CA1250048A - Combination magnetic transducer head apparatus - Google Patents
Combination magnetic transducer head apparatusInfo
- Publication number
- CA1250048A CA1250048A CA000503510A CA503510A CA1250048A CA 1250048 A CA1250048 A CA 1250048A CA 000503510 A CA000503510 A CA 000503510A CA 503510 A CA503510 A CA 503510A CA 1250048 A CA1250048 A CA 1250048A
- Authority
- CA
- Canada
- Prior art keywords
- magnetic
- head
- playback
- tracks
- recording
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/012—Recording on, or reproducing or erasing from, magnetic disks
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/488—Disposition of heads
- G11B5/4886—Disposition of heads relative to rotating disc
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/54—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head into or out of its operative position or across tracks
- G11B5/55—Track change, selection or acquisition by displacement of the head
- G11B5/5521—Track change, selection or acquisition by displacement of the head across disk tracks
- G11B5/5526—Control therefor; circuits, track configurations or relative disposition of servo-information transducers and servo-information tracks for control thereof
- G11B5/553—Details
- G11B5/5534—Initialisation, calibration, e.g. cylinder "set-up"
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B5/596—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks
- G11B5/59633—Servo formatting
Abstract
Abstract of the Disclosure A combination magnetic transducer head apparatus which can easily achieve initial formatting of data tracks of a rotating magnetic recording medium such as a hard disk without using a specific separate initial formatting system. The apparatus comprises a magnetic head for initial formatting, another magnetic head for servo control and a magnetic recording and playback head all mounted on a head slider. In the apparatus, at least one track is first recorded on a magnetic disk by the magnetic head for initial formatting and then another track is recorded by the magnetic recording and playback head while the first track is scanned by the magnetic head for servo control whereafter such a series of operations are repeated until completion of recording of all tracks required.
Description
i~2S~ 8 Background of the Invention This invention relates to a magnetic head apparatus which is used to record and reproduce signals to and from a rotating magnetic recortling medium such as a magnetic disk, and more particularly to a combination magnetic transducer head apparatus which can easily achieve initial formatting of data tracks.
When data signals are to be recorded to or reproduced from a rotating magnetic recording medium such as, for example, a hard disk, it is necessary, particularly upon recording, to form tracks of a regular pitch on the rotating magnetic recording medium.
Accordingly, in a conventional apparatus wherein a large number of hard disks are arranged for rotation in an integral relationship, tracking signals are prerecorded in an equal pitch on one of the hard disks so that while the tracking signals are referred to, positions in radial directions of magnetic heads for recording data signals to the o-ther hard disks are controlled to record data signals to any of the hard disks. Such an apparatus has no problems where a large number of hard disks are rotated in an integral relationship, but where data signals are recorded to or reproduced from one or two hard disks, it is not suitable from a point of view ~$
~5~
of a space and a cost because it requires an additional hard disk for tracking signals.
Also, in order to record data signals on each hard disk so as to form tracks which have regularly arranged pitches, an apparatus is proposed which records position signals in the form of dots at positions in a radial direction at which individual tracks are to be formed.
Since the apparatus only records position signaLs in the form of dots at positions in a radial direction at which individual tracks are to be formed, it is difficult to record regularly pitched tracks over an entire circumference of a hard disk.
However, in such conventional apparatus, a specific initial formatting system is required, which leads to a drawback that factory equipments become expensive.
~ esides, if a magnetic disk is initialized on an initial formatting system other than a magnetic disk device, it may yield an eccentric motion relative to a spindle when it is mounted as a product on a magnetic disk system. This may cause a deterioration in accuracy of a positioning servo mechanism.
Objects and Summary of the Invention It is an object of the present invention to pro~ide ~'~5L)~
a novel combination magnetic transducer head apparatus suitable for use with a magnetic disk.
It is another object of the invention to provide a combination magnetic transducer head apparatus which can easily achieve initial formatting of data tracks of a magnetic disk.
It is a further object of the invention to provide a combination magnetic transducer head apparatus having a recording head for initial formatting of data tracks of a magnetic disk.
It is a still further object of the invention to provide a combination magnetic transducer head apparatus which can precisely achieve initial formatting of data trachs of and tracking servo control for a magnetic disk.
According to one aspect of the present invention, there is provided a combination magnetic transducer head apparatus, comprising a slider; a magnetic recording head formed on said slider for writing reference si~nal tracks on a rotating magnetic recording medium; the reference signal tracks having a predetermined track pitch P and a predetermined track width W; a servo control magnetic head formed on said slider; and a magnetic recording and playback head formed on said . .
~S~Q~8 slider for recording and playback of signals on the magnetic recording medium; said servo control magnetic head and said magnetic recording and playback head being provided on said slider with such a positional relation that said magnetic recording and playback head records a signal track adjacent one of said reference signal tracks with the predetermined pitch on detecting the reference signal -track using said servo control magnetic head.
According to another aspect of the invention, there is provided a combination magnetic transducer head apparatus, comprising a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic he&d mounted on said slider, a pair of tracking signal playback magnetic heads mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having a plurality of head sections; whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium i5 P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a .
~Z~ 8 direction of -the arrangement of the tracks is selected to be equal to the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be nP
(where n=2, 3, ...), and the number of said head sections of said initial tracking signal recording magnetic head is selected to be n.
According to a further aspect of the invention, there is provided a combination magnetic transducer head apparatus, comprising a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking sional playback magnetic head mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having a plurality of head sections; whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium is P, the pitch of said plurality of head sections of said ~25~al9t8 initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be (n+1/2)P (where n=1, 2, 3, ...), and the number of said head sections of said initial tracking signal recording magnetic head is selected to be n~1.
According to a still further object of the invention, there is provided a comblnation magnetic transducer head apparatus, comprising a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking signal playback magnetic head mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having three or more head sections; whereby, where the pitch of tracks to be formed on the rotating magnetic -~5f~B
recording medium is P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to twice of the pitch P
of the -tracks while the distance in the direction of the arrangement of the tracks between the oenter of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be 3P.
Brief Description of the Drawings Fig. 1 is a diagrammatic representation illustrating general construction of a magnetic disk system to which a combination magnetic transducer head apparatus according to the present invention is applied;
Fig. 2 is a schematic illustration showing a relation between a slider having thereon a combination magnetic transducer head apparatus according to the invention and a magnetic disk;
Fig. 3 is a diagrammatic representation showing structure of several heads on a head slider and relations of the heads to data tracks on a face of a disk;
:~2s6~
Figs. ~ to 6 are diagrammatic representations illustrating initial formatting operations;
Figs. 7 to 9 are diagrammatic representations illustrating several examples of constructions of a combination magnetic transducer head apparatus according to the invention;
Fig. 10 is a diagrammatic representation illustrating an operation for initial formatting of data tracks by the combination magnetic transducer head apparatus of Fig. 9; and Figs. 11 to 13 are cross sectional views illustrating different exemplary magnetic heads for use with a combination magnetic transducer head apparatus according to the invention.
Description of the Preferred Embodiments A magnetic disk system for pickin~ up an envelope of signals from a data track to effect servo control according to the present invention includes a magne-tic head 7 for initial formatting, another ma~netic head 3 for servo control and a magnetic recording and playback head 9 all mounted on a head slider 2. In the magnetic disk system, at least one track is first recorded on a magnetic disk 1 by the magnetic head 7 for ini-tial .
~Z5~)Q'~
formatting and then another track is recorded by the magnetic recording and playback head 8 while the first track is scanned by the magnetic head ~ for servo control whereafter such a series of operations are repeated until completion of recording of all tracks required.
Referring to Fig. 1 which illustrates general construction of the embodiment of the invention, the magnetic disk system includes a head slider 2 mounted for movement in a radial direction over a magnetic disk 1. The head slider 2 has mounted thereon three different magnetic heads including a magnetic head for initial formatting, another magnetic head for servo control and a magnetic recording and playback head as ~
hereinafter described. The magnetic disk system further includes a servo control circuit 3 and an actuator 4 which constitute, together with the magnetic head for servo control on the head slider 2, a head positioning mechanism for controlling the position of the head slider 2.
The magnetic disk system further includes an initial formatting circuit 5 for driving the magnetic head for initial formatting on the head slider 2.
Certain recording signals are supplied from the initial ~2S6)0~
formatting circuit 5 to the magnetic head for initial formatting. Such recording signals may be a continuous square wave or some other data having some meanings.
The magnetic disk system further includes a data recording circuit 6 for driving the magnetic recording and playback head on the head slider 2. The ma_netic recording and playback head is naturally used for recording of data, but in the present embodiment, it is also used for initial formatting.
Referring now to Fig. 2 which illus-trates, in an enlarged scale, a relation between the magnetic disk 1 and the head slider 2, the magnetic disk 1 is rotated in a direction as indicated by an arrow mark a, and the head slider 2 is moved in a radial direction of the magnetic disk 1 as indicated by an arrow mark b by the actuator 4. A combination magnetic transducer head including the magnetic head for initial formatting, the magnetic head for servo control and the magnetic data recording and playback head is mounted at an end of the head slider on the trailing edge relative to the recording medium 1.
Referring now to Fig. 3 which illustrates structure of the individual magnetic heads on the head slider 2 and relations of the heads to data tracks on a face of :~ZS~Q~
the magnetic disk 1, the magnetic head for initial formatting is designated at 7 and is of the electromagnetic induction type which can record a plurality of, for example, three, tracks at a time. The magnetic head for servo control is designated at 8 and includes a pair of magnetic heads 8a and 8b which may be each constituted from, for example, a head of the magnetoresistance effect type (an MR head). The magnetic data recording and playback head is designated at 9.
The magnetic head 7 for initial formatting has a pair of terminals lOa and 10b and is connected to the initial formatting circuit 6 ~Fig. 1). The magnetic head 8 for servo control has three output terminals lla, 1lb and 11c. The terminal llc is grounded while the other output terminals lla and llb are connected to input terminals of a differential amplifier each by way of a capacitor, an amplifier, a filter and an envelope detect circuit though none of them are shown so that a position (displacement) signal may be obtained at an output of the differential amplifier as servo control information. The output of the differential amplifier is coupled to a differential circui.t which produces a velocity signal and also to a zero cross co~parator ~ r ~2X L3~
which produces a track passing signal. The velocity signal and the track passing signal serve as servo control information. Those signals are supplied to the servo contr~l circuit 3 (Fig. 1) in order to achieve, in response to the velocity signal and the track passing signal, a seek operation for moving the magnetic head from a certain track to another aimed track and then to achieve, in response to the position signal, a tracking operation to cause -the magnetic head to properly follow the latter track after the movement of the magnetic head. Meanwhile, the magnetic recording and playback head 9 has a pair of terminals 12a and 12b and is here connected to the data recording circuit 6 (Fig. 1).
Referring further to Fig. 3, reference symbol P
denotes a track pitch, G a guard band width and W a track width, and in the present embodiment, data tracks are recorded in an equal pitch with an equal track width on a disk face of a magnetic disk 1 using the three magnetic heads as described above.
Now, an initial formatting process for such data tracks will be described with reference to Figs. 4 to 6.
Referring first to Fig. ~, the head slider 3 is first positioned to a suitable position over the disk face of the magnetic disk 1, for e~ample, around an ~sv~
outer periphery of the magnetic disk 1, by a suitable means (for e~ample, an arm on which the head slider is supported may be abutted against a mechanical stopper without ser~o controlling the head slider).
Then, a recording signal is supplied from the initial formatting circuit 5 to the magnetic head 7 for initial formatti.ng so that a plurality of data tracks, for example, from the first to the third data tracks T
from the outer periphery of the magnetic disk, may be recorded at a time by the magnetic head 7 for initial formatting. The accuracy in dimension of the data tracks T then depends upon the accuracy in dimension of the magnetic head 7 for initial formatting and is really high.
Referring now to Fig. 5, the head slider 2 has been moved by one tra.ck pitch in an inward direction of the magnetic disk 1. Then, the first outermost data track T
is scanned by the magnetic head 8 for servo control to effect servo control. At the same time, a recording signal is supplied from the data recording circuit 6 to the magnetic recording and playback head 9 to record a fourth data track T from the outer periphery of the magnetic disk 1.
After then, such a series of operations are ~LZS63OE'~
repeated to record data trachs one after another until initial formatting is completed by completion of recording of all required tracl~s.
Construction of the combination magnetic transducer head appara-tus according -to the present invention will be described in detail below with reference to Figs. 7 to 13.
Referring first to Fig. 7, a hard disk as a rotating magnetic recording medium is desi~nated at 1 and includes a substrate lOla such as of aluminum and a pair of magnetic layers lOlb and lOlc formed on opposite faces of the substrate lOla. The magnetic layers may each be formed by coating magnetic powder of YFe203 or the like together with a binder or else may be ferromagnetic metal layers of a ferromagnetic metal such as Fe, Ni or ~o or an alloy of them formed using a physical vapour deposition technique such as vacuum deposition or sputtering or using electroplating or electroless plating. Here, only recording on and playback from one of the ferromagnetic layers, that is, the layer lOlb, will be described. Reference symbol T
denotes a track, and the tracks T are formed in concentrical relationship on the ferromagnetic layer lOlb. Further, reference symbol W denotes a width of ~5C3~
each track T, P a pitch of the tracks T, and G a guard band width. Accordingly, P=W+G.
A magnetic data signal recording and playback head is designated at 9 and is constituted, in the present embodiment, from a thin film type magnetic transducer head which can na-turally be replaced by a bulk type magnetic transducer head. The thin film type magnetic head is formed as a combination magnetic transducer head including an electromagnetic induction type magnetic transducer head section for recording and a magnetoresistance effect type magnetic transducer head section for playback.
A servo control head is designated at 8 and includes a pair of magnetic tracking signal playback heads 8a and 8b which ha~e a same trace width and are each constituted, in the present embodiment, from a magnetoresistance effect type thin film magnetic transducer head while it may otherwise be constituted from a bulk type magnetic transducer head or an electroma~netic induction type magnetic transducer head.
An initial tracking signal recording magnetic head is denoted at 7 and is constituted, in the present embodiment, from an electromagnetic induction type thin film magnetic transducer head while it may otherwise be .
o'~
constituted from a bulk type magnetic transducer head.
The initial tracking signal recording magnetic head 7 has a plurality of, 2 in the present embodiment, divided head sections 7a and 7b which define a magnetic gap therebetween and have cores having a common winding thereon and located in an opposing relationship to a magnetic disk. It is to be noted that the divided head sections may otherwise be formed as independent heads around which coils are wound independently of each other.
While the trace width of the data signal recording and playback magnetic head 9, particularly the trace width upon recording (this is substantially equal to the width of the magnetic gap), is selected to be equal to the width W of tracks T to be recorded or formed, it may otherwise be different a little from the latter. The trace width of the tracking signal playback magnetic head sections 8a and 8b (this width is substantially equal to the gap width~ is represented by h, the distance between the two head sections 8a and 8b is represented by S, and the distance between opposite side edges of each trace of the magnetic heads 8a and 8b is designa~ed by H. In an example of interrelations among those dimensions, ~ is equal to W, and h and S are equal ~2~4Z~
to G. Accordingly, H=W=3G. For example, G, h and S are 4.5 ~m, and W and H are 13.5 ~m.
OE the dimensions of the tracking signal p~ayback magnetic head sections 8a and 8b as described above, h must be smaller -than G in order to eliminate crosstalks while it is desirable to be greater than G in order to prevent saturation, and H must be greater than W in order that the difference between playback outputs of the magnetic head sections 8a and 8b may be zero when a middle point between the magnetic heads 8a and 8b is just at a middle point of a track T in its widthwise direction but may assume a different value when the magnetic head sections 8a and 8b are at any other positions, or in other words, in order to prevent appearance of a blind section. It is to be noted that while the crosstalk elimination require~ent and the saturation prevention requirement are contradictory upon production of a magnetic head, the former requirement i5 considered more serious and thus h is made smaller than or equals to G.
Now, dimensions of the initial tracking signal recording magnetic head 7 will be described. The pitch of the individual head sections 7a and 7b is selected to be equal to the pitch P of the tracks T. The trace 5(~Q~
width of the head sections 7a and 7b ~this is substantially equal to the gap width) is selected to be equal to the width W of the tracks T, but it may be different a little from the latter.
Now, positional relations among the magnetic heads 7, 8a, 8b and 9 will be described. Referring to Fig. 7, the abscissa x indicates a radius of a rotating magnetic recording medium 1 and the value increases toward the outer periphery from the center of the rotating magnetic recording medium 1. In the present embodiment, the data signal recording and playback magnetic head 9 is located adjacent the outer periphery of the rotating magnetic recording medium 1 and the initial tracking signal recording magnetic head 7 is located at an innermost position while the tracking signal playback magnetic heads 8a and 8b are located inbetween. The combination magnetic transducer head including the magnetic heads 7, 8 and 9 is mounted on an end face of the slider 2 as shown in Fig. 2. Referring again to Fig. 2, reference symbols a and b indicate a direction of rotation of the rotating magnetic recording medium 1 and a direction of I -movement of the slider 2, respectively. It is to be noted that the data signal recording and playback magnetic head 9 is preferably located at an outer . .
.
;~2S~Q~3 position of the rotating magnetic recordin~ medium 1 than -the initial tracking signal recording magnetic heads 7 in order to record data signals, but an arrangement of the heads 7, 8a, 8b and 9 i6 not necessarily be limited to this and they can be arranged in any order in the direction of the arrangement of the tracks.
Referring back -to Fig. 7, positions of -the centers and opposite ends of gaps of the individual heads 7, 8a, 8b and 9 are indicated on the abscissa x. Herel the origin of the abscissa x is at the center of the gap of the data signal recording and playback magnetic head 9.
The distance in the direction of the arrangement of the tracks between the center of the trace width of the data signal reoording and playback magnetic head 9, that is, the origin O, and the center between the traces of the pair of tracking signal playback magnetic heads 8a and 8b, that is, the center between the gaps, is generally represented nP (where n=2, 3, ...), and here n=2 and thus the example where the distance is 2P is shown. The number n of head sections of the initial tracking signal recording magnetic head 7 is determined in accordance with the value n of the distance nP in the direction of the arrangement of the tracks between the center of the ~51UQ~3 trace (the center of the gap) of the data signal recording and playback magnetic head 9 and the center between the traces ~the center of the gaps) of the tracking signal playback magnetic heads 8a and 8b, and in this case the number is 2.
As for the initial track:ing signal recording magnetic head 7, positions of the center of the gap, that is, the center of the trace width, and both ends of the head section 7b are indicated on the abscissa ~ with reference to the center ~0 of the gap, that is, the center of the trace width, of the head section 7a which is located adjacent the tracking signal playback magnetic head 8b.
Now, operations of the combination magnetic transducer head apparatus according to the present embodiment will be described. When data signals are to be recorded on a rotating magnetic recording medium 1, at first suitable digital signals are supplied to the initial tracking signal recording magnetic head 7 to effect recording to form two reference tracks at an inner circumferential portion of the rotating magnetic recording medium 1 at a time. Then, a same one of the reference tracks of the rotating magnetic recording medium 1 is reproduced at a time by means of the :~2S~
tracking signal playback magnetic heads 8a and 8b, and the positions of the individual magnetic heads are controlled such that the difference between playback outputs thereof may be reduced to zero, and at the same time data signals are recordecl by means of the data signal recording and playback magnetic head 9. After then, the tracks recorded by the data signal recording and playback magnetic head 9 are reproduced in a similar manner by the tracking signal playback magnetic heads 8a and 8b while at the same time data signals are recorded by the data signal recording and playback magnetic head 9.
On the other hand, upon reproduction, while tracking is aehieved by means of the tracking signal playback magnetic heads 8a and 8b, data signals of a seleeted track are reprodueed by the data signa recording and playbaek magnetie head 9.
Playback signals reproduced from the tracking signal playback magnetie heads 8a and 8b are supplied to respective envelope detect circuits by way of respeetive amplifiers and filters not shown, and outputs of the detection signals of the envelope deteet cireuits are supplied to a differential amplifier. Outpu-t of the differential amplifier is a traeking error signal when ~s~
tracks are scanned, hut is a signal which indicates a position of a rotating magnetic recording medium 1 in its radial direction ~hen the magnetic heads move transversely across tracks. Upon scanning of tracks, positions of the magnetic heads 7, 8a, 8b and 9 in a radial direction of a rotating magnetic recording medium are controlled in response to such a tracking error signal. The differential output of the differential amplifier is supplied to a differential circuit and a zero cross detector. Output of the differential circuit is a signal which indicates a scanning velocity of the magnetic heads when they move transversely across tracks. Output of the zero cross detector is a signal which indicates a numerical value corresponding to the r number of those tracks which are passed by the magnetic heads when the latter move transversely across tracks.
It is to be noted that when tracking of the data signal recording and playback magnetic head 9 is achieved just upon a track T, the center between the traces of the tracking signal playback magnetic heads 8a and 8b is positioned at the center of the width of the track T.
Now, structure of the individual m~gnetic heads described above will be described with reference to ~25~
Figs. 7 and 11 to 13. Referring first to Fig. 9, structure of the data signal recording and playback magnetic head 9 is shown. The data signal recording and playback magnetic head 9 is constituted from a combination thin film type magnetic transducer head including an electromagnetic induction type magnetic transducer head section and a magnetoresistance effect type magnetic transducer head section as described hereinabove. In particularl various elements as hereinafter described are formed on a magnetic substrate 51 by way of a nonmagnetic insulating layer such as of SiO2 not shown. At first, a magnetoresistance effect sensing portion 54 is formed above the magnetic substrate 51 with a gap g left therebetween, and a magnetic layer 56 is formed in a magnetically coupled relationship above the magnetoresistance effect sensing portion 54. The magnetic layer 56 is magnetically directly coupled to a magnetic yoke 52 described below.
A pair of conductive layers 53 and 55 are disposed above and below the magnetic layer 56, respectively. The magnetic yoke 52 is disposed above the magnetoresistance effect sensing portion 54, the magnetic layer 56 and the conductive layer 55, and has one end thereof magnetically directly coupled to the magnetic substrate ~;~5~
51 and the other end thereof located adjacent -the gap g.
Upon reproduction, the magnetic head 9 acts as an magnetoresistance effect type magnetic transducer head, and the conductive layers 53 and 55 are energized with DG currents flowing in mutually opposite directions as perpendicular to the face of the drawing to provide the magnetoresistance effect sensing portion 54 with a bias magnetic field to raise the sensitivity of the latter when data signals are reproduced. On the other hand, upon recording, the magnetic head 9 acts a.s an electromagnetic induction type magnetic head, and the conductive layers 63 and 55 are energized with recording currents flowing in a same direction as perpendicular to the face of the drawing. In this case, the magnetic layer 56 should be passed by little magnetic fluxes. It is to be mentioned here that in Fig. 7, reference symbols 54a and 54b denote each a connecting conductive layer led out from the magnetoresistance effect sensing portion 54, 55a and 55b each a connecting conductive layer led out from the conductive layer 5~, and 53a and 53b each a connecting conductive layer led out from the conductive layer 53.
Structure of the tracking signal playback magnetic head sections 8a and 8b will be described below with ~2S~
reference -to Figs. 7 and 12. The tracking signal playbacls magnetic head sections 8a and 8b are each constituted from a magnetoresistance effect type thin film magnetic transducer head. Several elements are formed on a magnetic substrate 61 by way of a nonmagnetic insulating layer such as of SiO2. A yoke is formed on the magnetic substrate 61 and includes two yoke sections 62a and 62b disposed in a spaced relationship by a predetermined distance from each other. A gap g is defined between one end of the yoke section 62a and one end of the magnetic substrate 61. A
magnetoresistance effect sensing portion 64 and a bias conductive layer 63 below are disposed between the magnetic yoke sections 62a and 62b and the magnetic substrate 61. Thus, a bias magnetic field is provided to the magnetoresistance effect sensing portion 64 so that the sensitivity of the magnetic head sections 8a and 8b may be raised by energizing the bias conductive layer 63 with a DC current. It is to be mentioned that in Fig. 7, reference numerals 64a, 64b and 64c denote connecting conductive layers led out from opposite ends of the magnetoresistance effect sensing portions 64 of the magnetic head sections 8a and 8b, and 63a and 63b denote connecting conductive layers led out from o~
opposite ends of the bias conduc-tive layer 63.
Now, construction of the initial tracking signal recording magnetic head 7 will be described with reference to Figs. 7 and 13. The initial tracking signal recording magnetic head 7 is constituted, in the present embodlment, from an electromagnetic induction type thin film magnetic head as described hereinabove.
Several elements are formed on a magnetic substrate 71 by way of a nonmagnetic insulating layer such as of SiO2. A yoke 72 is formed on the magnetic substrate 71 and has one end thereof magnetically directly coupled to the magnetic substrate 71. A gap g is defined between -the other channel-shaped end of the yoke 72 and one end of the magnetic substrate 71. A conductive layer 73 is located between the yoke 72 and the magnetic substrate 71. Thus, tracking signals can be recorded by energizing the conductive layer 73 with an electric current of recording tracking signals (digital signals).
It is to be mentioned that in Fig. 7, reference symbols 73a and 73b are connecting conductive layers led out from opposite ends of the conductive layer 73.
Another embodiment of a combination magnetic transducer head apparatus according to the present invention will now be described with reference to Fig.
~s~
8. In Fig. 8, like parts or elements are denoted by like reference symbols to those in Fig. 7, and repeated description thereof will be omitted herein. The combination magnetic transducer head apparatus of Fig. 8 also includes a data signal recording and playback magnetic head 9, a pair of tracking signal playback magnetic heads 8a and 8b and a magnetic head 7 for initial formatting. The trace width of each of the magnetic heads is selected in a similar manner to that of the embodiment of Fig. 7. In the arrangement of Fig.
8, the tracking signal playback magnetic heads 8a and 8b are disposed to trace end portions of two adjacent recording tracks to produce tracking signals.
In Fig. 8, positions of the centers and opposite~
ends of gaps of the magnetic heads 7, 8 and 9 are indicated on the abscissa x. In this case, the origin of the abscissa x is at the center of the gap of the data signal recording and playback magnetic head 9. The distance in the direction of the arrangement of tracks between the center of the trace width of the data signal recording and playback magnetic head 9, that is, the origin 0, and the center between the traces of the pair of tracking signal playback magnetic heads 8a and 8b, that is, the center between the gaps, is generally represented (n+l/2)P ( where n=1, 2, 3, ...), and here n=2 and thus the e~ample where the distance is (~/2)P is shown. The quantity or number n+l of head sections of the initial tracking signal recording magnetic head 7 is determined in accordance with the value n of the distance (n+l/2)P in the direction of the arrangement of the tracks between the center of the trace (the center of the gap) of the data signal recording and playback magnetic head 9 and the center between the traces (the center of the gaps) of the tracking signal playback magnetic heads 8a and 8b, and in this case the number is 3.
As for the initlal tracking signal recording magnetic head 7, positions of the center of the gap, that is, the center of the trace width, and both ends of the head sections 7b and 7c are indicated on the abscissa x with reference to the center xO of the gap, that is, the center of the trace width, of the head section 7a which is located adjacent the tracking signal playback magnetic head 8b.
Now, operations of the combination magnetic transducer head apparatus according to the present embodiment will be described. When data signals are to be recorded on a rotating magnetic recording medium 1, :~5C~
at first suitable digital signals are supplied to the initial tracking signal recording magnetic head 7 to effect recording to form three reference tracks at an inner circumferential portion of the rotating magnetic recording medium 1 at a time. Then, inner two of the reference tracks of the rotating magnetic recording medium 1 are reproduced at a time by means of the tracking signal playback magnetic heads 8a and 8b, and the positions of the individual magnetic heads are controlled such that the difference between playback outputs thereof may be reduced to zero, and at the same time data signals are recorded by means of the data signal recording and playback magnetic head 9. After then, the tracks recorded by the data signal recording ~.
and playback magnetic head 9 are reproduced in a similar manner by the tracking signal playback magnetic heads 8a and 8b while at the same time data signals are recorded by the data signal recording and playback magnetic head 9.
On the other hand, upon reproduction, while tracking is achieved by means of the tracklng signal playback magnetic heads 8a and 8b, data signals of a selected track are reproduced by the data signal recording and playback magnetic head 9.
)0~8 Outputs of the tracking signal playback magnetic heads 8a and 8b are used to produce, in a similar manner to that of the arrangement of Fig. 7, a tracking error signal, a velocity signal when the magnetic heads move transversely across tracks, and a servo control signal for recording or reproducing a desired track by signal processing such as counting for jumping over of a number of tracks.
It is to be noted that when tracking of the data signal recording and playback magnetic head 9 is achieved just upon a track T, the center between the traces of the tracking signal playback magnetic heads 8a and 8b is positioned at the center of thé width of the track T. ~
Further, the individual magnetic heads may be any of such heads as shown in Figs. 11 to 13.
Now, a further embodiment of a combination magnetic transducer head apparatus according to the present invention will be desoribed with reference to Figs. 9 and 10.
At first, dimensions of an initial tracking signal recording magnetic head 7 will be described. The pitch PO of head sections 7a, 7b and 7c of the magnetic head 7 is selected to be twice of the pitch of tracks T, that 125~
is, equal to 2P. The trace width of the head sections 7a, 7b and 7c is selected to be equal to the width W of each track T, but it may be a little different from the latter.
Meanwhile, the distance L in a direction of an arrangement of the tracks between the center of the trace width of the data si~nal recording and playback magnetic head 9 and the center between the traces, that is, the center between gaps, of a pair of tracking signal playback magnetic heads 8a and 8b is selected to be three times of the pitch P of the tracks T, that is, to be 3P.
Now, positional relations of the magnetie heads 9 8a, 8b and 7 will be described. Referring to Fig. 9, the direction from the center of a rotating magnetic recording medium 1 to the outer periphery thereof eorresponds to a direetion of the abscissa x indicated by an arrow mark. In the present embodiment, the data signal reeording and playback magnetic head 9 is loeated adjacent the outer periphery of the rotating magnetic recording medium 1 and the initial tracking signal recording magnetic head 7 is located at an innermost position while the traching signal playback magnetic heads 8a and 8b are located inbetween. The combination :~2~;~Q~
magnetic transducer head incl-lding the magnetic heads 7, 8 and 9 is mounted on an end face of the slider 2 as shown in Fig. 2.
Now, operations o the combination magnetic transducer head apparatus according to the present embodiment will be described. When data signals are to be recorded on a rotating magnetic recording medium 1, at first suitable digital signals are supplied to the initial tracking signal recording magnetic head 7 to effect recording to form two reference tracks at an inner circumferential portion of the rotating magnetic recording medium 1 at a time. Then, a same one of the reference tracks of the rotating magnetic recording medium 1 is reproduced at a time by means of the tracking signal playbaek magnetic heads 8a and 8b, and the positions of ths individual magnetic heads are controlled sueh that the differenee between playbaek outputs thereof may be redueed to zero, and at the same time data signals are reeorded by means of the data signal recording and playbaek magnetie head 9. After then, a data traek formed between the referenee traeks and a reference traek are alternately reproduced in a similar manner while at the same time data signals are recorded by means of the data signal recording and ~v~
playbacls magnetic head 9. Thereafter, data tracks recorded one after another are reproduced in a similar manner while at the same time data signals are recorded by the data signal recording and playback magnetic head 9.
In particular, after reference tracks STl, ST2 and ST3 have been recorded at track positions 1, 3 and 5 as shown in Fig. 10 by the initial tracking signal recording magnetic head 7, while the reference tracks STl, ST2 and ST3 are being tracked by the tracking signal playbacls magnetic head 8, data tracks DTl and DT2 are recorded, that is, the data track DTl is formed with reference to the reference track STl at the position 1 and the data track DT2 is formed at a position 6 with reference to the reference track ST2 at the position 3.
After then, data tracks DT3~ DT4, DT5 ... are formed one after another while the data track DTl at the position 4, the reference track ST3 at the position 5, the data track DT3 at the position 6 ... are tracked one after another.
On the other hand, upon reproduction, data signals of a desired track are reproduced by the data signal recording and playback magnetic head 9 while tracking is achieved by the tracking signal playbacls magnetic heads ~zs~
8a and 8b.
In the initial tracking signal recording magnetic head 7 according to the present embodiment, gaps of the head sections 7a, 7b and 7c and clearances between adjacent ones thereof are formed with accurate dimensions particularly because the pitch of the head sections 7a, 7b and 7c of the magnetic head 7 is PO
which is equal to twice of the pitch P of tracks to be formed by ~agnetic recording (thus, Po=2P).
Accordingly, recording of good initial tracking signals is achieYed wi-th an accura-te width of tracks and also with an accurate distance between adjacent tracks.
As apparent from the foregoing description, according to the present invention, a magnetic head for ini-tial formatting is located on a head slider together with a magnetic head for servo control and a magnetic recording and reproducing head. Accordingly, initial formatting can be achie~ed by a magnetic disk system itself without using a specific initial form~tting system, and hence construction can be simplified and a cost therefor can be reduced.
In addition, since initial formatting can be achie~ed by a magnetic disk system itself, no deterioration in accuracy of a positioning ser~o control 3~
~54~8 mechanism will occur due to initialization by a separate initial format-ting sys-te-n as in a conventional technique.
When data signals are to be recorded to or reproduced from a rotating magnetic recording medium such as, for example, a hard disk, it is necessary, particularly upon recording, to form tracks of a regular pitch on the rotating magnetic recording medium.
Accordingly, in a conventional apparatus wherein a large number of hard disks are arranged for rotation in an integral relationship, tracking signals are prerecorded in an equal pitch on one of the hard disks so that while the tracking signals are referred to, positions in radial directions of magnetic heads for recording data signals to the o-ther hard disks are controlled to record data signals to any of the hard disks. Such an apparatus has no problems where a large number of hard disks are rotated in an integral relationship, but where data signals are recorded to or reproduced from one or two hard disks, it is not suitable from a point of view ~$
~5~
of a space and a cost because it requires an additional hard disk for tracking signals.
Also, in order to record data signals on each hard disk so as to form tracks which have regularly arranged pitches, an apparatus is proposed which records position signals in the form of dots at positions in a radial direction at which individual tracks are to be formed.
Since the apparatus only records position signaLs in the form of dots at positions in a radial direction at which individual tracks are to be formed, it is difficult to record regularly pitched tracks over an entire circumference of a hard disk.
However, in such conventional apparatus, a specific initial formatting system is required, which leads to a drawback that factory equipments become expensive.
~ esides, if a magnetic disk is initialized on an initial formatting system other than a magnetic disk device, it may yield an eccentric motion relative to a spindle when it is mounted as a product on a magnetic disk system. This may cause a deterioration in accuracy of a positioning servo mechanism.
Objects and Summary of the Invention It is an object of the present invention to pro~ide ~'~5L)~
a novel combination magnetic transducer head apparatus suitable for use with a magnetic disk.
It is another object of the invention to provide a combination magnetic transducer head apparatus which can easily achieve initial formatting of data tracks of a magnetic disk.
It is a further object of the invention to provide a combination magnetic transducer head apparatus having a recording head for initial formatting of data tracks of a magnetic disk.
It is a still further object of the invention to provide a combination magnetic transducer head apparatus which can precisely achieve initial formatting of data trachs of and tracking servo control for a magnetic disk.
According to one aspect of the present invention, there is provided a combination magnetic transducer head apparatus, comprising a slider; a magnetic recording head formed on said slider for writing reference si~nal tracks on a rotating magnetic recording medium; the reference signal tracks having a predetermined track pitch P and a predetermined track width W; a servo control magnetic head formed on said slider; and a magnetic recording and playback head formed on said . .
~S~Q~8 slider for recording and playback of signals on the magnetic recording medium; said servo control magnetic head and said magnetic recording and playback head being provided on said slider with such a positional relation that said magnetic recording and playback head records a signal track adjacent one of said reference signal tracks with the predetermined pitch on detecting the reference signal -track using said servo control magnetic head.
According to another aspect of the invention, there is provided a combination magnetic transducer head apparatus, comprising a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic he&d mounted on said slider, a pair of tracking signal playback magnetic heads mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having a plurality of head sections; whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium i5 P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a .
~Z~ 8 direction of -the arrangement of the tracks is selected to be equal to the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be nP
(where n=2, 3, ...), and the number of said head sections of said initial tracking signal recording magnetic head is selected to be n.
According to a further aspect of the invention, there is provided a combination magnetic transducer head apparatus, comprising a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking sional playback magnetic head mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having a plurality of head sections; whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium is P, the pitch of said plurality of head sections of said ~25~al9t8 initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be (n+1/2)P (where n=1, 2, 3, ...), and the number of said head sections of said initial tracking signal recording magnetic head is selected to be n~1.
According to a still further object of the invention, there is provided a comblnation magnetic transducer head apparatus, comprising a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking signal playback magnetic head mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having three or more head sections; whereby, where the pitch of tracks to be formed on the rotating magnetic -~5f~B
recording medium is P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to twice of the pitch P
of the -tracks while the distance in the direction of the arrangement of the tracks between the oenter of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be 3P.
Brief Description of the Drawings Fig. 1 is a diagrammatic representation illustrating general construction of a magnetic disk system to which a combination magnetic transducer head apparatus according to the present invention is applied;
Fig. 2 is a schematic illustration showing a relation between a slider having thereon a combination magnetic transducer head apparatus according to the invention and a magnetic disk;
Fig. 3 is a diagrammatic representation showing structure of several heads on a head slider and relations of the heads to data tracks on a face of a disk;
:~2s6~
Figs. ~ to 6 are diagrammatic representations illustrating initial formatting operations;
Figs. 7 to 9 are diagrammatic representations illustrating several examples of constructions of a combination magnetic transducer head apparatus according to the invention;
Fig. 10 is a diagrammatic representation illustrating an operation for initial formatting of data tracks by the combination magnetic transducer head apparatus of Fig. 9; and Figs. 11 to 13 are cross sectional views illustrating different exemplary magnetic heads for use with a combination magnetic transducer head apparatus according to the invention.
Description of the Preferred Embodiments A magnetic disk system for pickin~ up an envelope of signals from a data track to effect servo control according to the present invention includes a magne-tic head 7 for initial formatting, another ma~netic head 3 for servo control and a magnetic recording and playback head 9 all mounted on a head slider 2. In the magnetic disk system, at least one track is first recorded on a magnetic disk 1 by the magnetic head 7 for ini-tial .
~Z5~)Q'~
formatting and then another track is recorded by the magnetic recording and playback head 8 while the first track is scanned by the magnetic head ~ for servo control whereafter such a series of operations are repeated until completion of recording of all tracks required.
Referring to Fig. 1 which illustrates general construction of the embodiment of the invention, the magnetic disk system includes a head slider 2 mounted for movement in a radial direction over a magnetic disk 1. The head slider 2 has mounted thereon three different magnetic heads including a magnetic head for initial formatting, another magnetic head for servo control and a magnetic recording and playback head as ~
hereinafter described. The magnetic disk system further includes a servo control circuit 3 and an actuator 4 which constitute, together with the magnetic head for servo control on the head slider 2, a head positioning mechanism for controlling the position of the head slider 2.
The magnetic disk system further includes an initial formatting circuit 5 for driving the magnetic head for initial formatting on the head slider 2.
Certain recording signals are supplied from the initial ~2S6)0~
formatting circuit 5 to the magnetic head for initial formatting. Such recording signals may be a continuous square wave or some other data having some meanings.
The magnetic disk system further includes a data recording circuit 6 for driving the magnetic recording and playback head on the head slider 2. The ma_netic recording and playback head is naturally used for recording of data, but in the present embodiment, it is also used for initial formatting.
Referring now to Fig. 2 which illus-trates, in an enlarged scale, a relation between the magnetic disk 1 and the head slider 2, the magnetic disk 1 is rotated in a direction as indicated by an arrow mark a, and the head slider 2 is moved in a radial direction of the magnetic disk 1 as indicated by an arrow mark b by the actuator 4. A combination magnetic transducer head including the magnetic head for initial formatting, the magnetic head for servo control and the magnetic data recording and playback head is mounted at an end of the head slider on the trailing edge relative to the recording medium 1.
Referring now to Fig. 3 which illustrates structure of the individual magnetic heads on the head slider 2 and relations of the heads to data tracks on a face of :~ZS~Q~
the magnetic disk 1, the magnetic head for initial formatting is designated at 7 and is of the electromagnetic induction type which can record a plurality of, for example, three, tracks at a time. The magnetic head for servo control is designated at 8 and includes a pair of magnetic heads 8a and 8b which may be each constituted from, for example, a head of the magnetoresistance effect type (an MR head). The magnetic data recording and playback head is designated at 9.
The magnetic head 7 for initial formatting has a pair of terminals lOa and 10b and is connected to the initial formatting circuit 6 ~Fig. 1). The magnetic head 8 for servo control has three output terminals lla, 1lb and 11c. The terminal llc is grounded while the other output terminals lla and llb are connected to input terminals of a differential amplifier each by way of a capacitor, an amplifier, a filter and an envelope detect circuit though none of them are shown so that a position (displacement) signal may be obtained at an output of the differential amplifier as servo control information. The output of the differential amplifier is coupled to a differential circui.t which produces a velocity signal and also to a zero cross co~parator ~ r ~2X L3~
which produces a track passing signal. The velocity signal and the track passing signal serve as servo control information. Those signals are supplied to the servo contr~l circuit 3 (Fig. 1) in order to achieve, in response to the velocity signal and the track passing signal, a seek operation for moving the magnetic head from a certain track to another aimed track and then to achieve, in response to the position signal, a tracking operation to cause -the magnetic head to properly follow the latter track after the movement of the magnetic head. Meanwhile, the magnetic recording and playback head 9 has a pair of terminals 12a and 12b and is here connected to the data recording circuit 6 (Fig. 1).
Referring further to Fig. 3, reference symbol P
denotes a track pitch, G a guard band width and W a track width, and in the present embodiment, data tracks are recorded in an equal pitch with an equal track width on a disk face of a magnetic disk 1 using the three magnetic heads as described above.
Now, an initial formatting process for such data tracks will be described with reference to Figs. 4 to 6.
Referring first to Fig. ~, the head slider 3 is first positioned to a suitable position over the disk face of the magnetic disk 1, for e~ample, around an ~sv~
outer periphery of the magnetic disk 1, by a suitable means (for e~ample, an arm on which the head slider is supported may be abutted against a mechanical stopper without ser~o controlling the head slider).
Then, a recording signal is supplied from the initial formatting circuit 5 to the magnetic head 7 for initial formatti.ng so that a plurality of data tracks, for example, from the first to the third data tracks T
from the outer periphery of the magnetic disk, may be recorded at a time by the magnetic head 7 for initial formatting. The accuracy in dimension of the data tracks T then depends upon the accuracy in dimension of the magnetic head 7 for initial formatting and is really high.
Referring now to Fig. 5, the head slider 2 has been moved by one tra.ck pitch in an inward direction of the magnetic disk 1. Then, the first outermost data track T
is scanned by the magnetic head 8 for servo control to effect servo control. At the same time, a recording signal is supplied from the data recording circuit 6 to the magnetic recording and playback head 9 to record a fourth data track T from the outer periphery of the magnetic disk 1.
After then, such a series of operations are ~LZS63OE'~
repeated to record data trachs one after another until initial formatting is completed by completion of recording of all required tracl~s.
Construction of the combination magnetic transducer head appara-tus according -to the present invention will be described in detail below with reference to Figs. 7 to 13.
Referring first to Fig. 7, a hard disk as a rotating magnetic recording medium is desi~nated at 1 and includes a substrate lOla such as of aluminum and a pair of magnetic layers lOlb and lOlc formed on opposite faces of the substrate lOla. The magnetic layers may each be formed by coating magnetic powder of YFe203 or the like together with a binder or else may be ferromagnetic metal layers of a ferromagnetic metal such as Fe, Ni or ~o or an alloy of them formed using a physical vapour deposition technique such as vacuum deposition or sputtering or using electroplating or electroless plating. Here, only recording on and playback from one of the ferromagnetic layers, that is, the layer lOlb, will be described. Reference symbol T
denotes a track, and the tracks T are formed in concentrical relationship on the ferromagnetic layer lOlb. Further, reference symbol W denotes a width of ~5C3~
each track T, P a pitch of the tracks T, and G a guard band width. Accordingly, P=W+G.
A magnetic data signal recording and playback head is designated at 9 and is constituted, in the present embodiment, from a thin film type magnetic transducer head which can na-turally be replaced by a bulk type magnetic transducer head. The thin film type magnetic head is formed as a combination magnetic transducer head including an electromagnetic induction type magnetic transducer head section for recording and a magnetoresistance effect type magnetic transducer head section for playback.
A servo control head is designated at 8 and includes a pair of magnetic tracking signal playback heads 8a and 8b which ha~e a same trace width and are each constituted, in the present embodiment, from a magnetoresistance effect type thin film magnetic transducer head while it may otherwise be constituted from a bulk type magnetic transducer head or an electroma~netic induction type magnetic transducer head.
An initial tracking signal recording magnetic head is denoted at 7 and is constituted, in the present embodiment, from an electromagnetic induction type thin film magnetic transducer head while it may otherwise be .
o'~
constituted from a bulk type magnetic transducer head.
The initial tracking signal recording magnetic head 7 has a plurality of, 2 in the present embodiment, divided head sections 7a and 7b which define a magnetic gap therebetween and have cores having a common winding thereon and located in an opposing relationship to a magnetic disk. It is to be noted that the divided head sections may otherwise be formed as independent heads around which coils are wound independently of each other.
While the trace width of the data signal recording and playback magnetic head 9, particularly the trace width upon recording (this is substantially equal to the width of the magnetic gap), is selected to be equal to the width W of tracks T to be recorded or formed, it may otherwise be different a little from the latter. The trace width of the tracking signal playback magnetic head sections 8a and 8b (this width is substantially equal to the gap width~ is represented by h, the distance between the two head sections 8a and 8b is represented by S, and the distance between opposite side edges of each trace of the magnetic heads 8a and 8b is designa~ed by H. In an example of interrelations among those dimensions, ~ is equal to W, and h and S are equal ~2~4Z~
to G. Accordingly, H=W=3G. For example, G, h and S are 4.5 ~m, and W and H are 13.5 ~m.
OE the dimensions of the tracking signal p~ayback magnetic head sections 8a and 8b as described above, h must be smaller -than G in order to eliminate crosstalks while it is desirable to be greater than G in order to prevent saturation, and H must be greater than W in order that the difference between playback outputs of the magnetic head sections 8a and 8b may be zero when a middle point between the magnetic heads 8a and 8b is just at a middle point of a track T in its widthwise direction but may assume a different value when the magnetic head sections 8a and 8b are at any other positions, or in other words, in order to prevent appearance of a blind section. It is to be noted that while the crosstalk elimination require~ent and the saturation prevention requirement are contradictory upon production of a magnetic head, the former requirement i5 considered more serious and thus h is made smaller than or equals to G.
Now, dimensions of the initial tracking signal recording magnetic head 7 will be described. The pitch of the individual head sections 7a and 7b is selected to be equal to the pitch P of the tracks T. The trace 5(~Q~
width of the head sections 7a and 7b ~this is substantially equal to the gap width) is selected to be equal to the width W of the tracks T, but it may be different a little from the latter.
Now, positional relations among the magnetic heads 7, 8a, 8b and 9 will be described. Referring to Fig. 7, the abscissa x indicates a radius of a rotating magnetic recording medium 1 and the value increases toward the outer periphery from the center of the rotating magnetic recording medium 1. In the present embodiment, the data signal recording and playback magnetic head 9 is located adjacent the outer periphery of the rotating magnetic recording medium 1 and the initial tracking signal recording magnetic head 7 is located at an innermost position while the tracking signal playback magnetic heads 8a and 8b are located inbetween. The combination magnetic transducer head including the magnetic heads 7, 8 and 9 is mounted on an end face of the slider 2 as shown in Fig. 2. Referring again to Fig. 2, reference symbols a and b indicate a direction of rotation of the rotating magnetic recording medium 1 and a direction of I -movement of the slider 2, respectively. It is to be noted that the data signal recording and playback magnetic head 9 is preferably located at an outer . .
.
;~2S~Q~3 position of the rotating magnetic recordin~ medium 1 than -the initial tracking signal recording magnetic heads 7 in order to record data signals, but an arrangement of the heads 7, 8a, 8b and 9 i6 not necessarily be limited to this and they can be arranged in any order in the direction of the arrangement of the tracks.
Referring back -to Fig. 7, positions of -the centers and opposite ends of gaps of the individual heads 7, 8a, 8b and 9 are indicated on the abscissa x. Herel the origin of the abscissa x is at the center of the gap of the data signal recording and playback magnetic head 9.
The distance in the direction of the arrangement of the tracks between the center of the trace width of the data signal reoording and playback magnetic head 9, that is, the origin O, and the center between the traces of the pair of tracking signal playback magnetic heads 8a and 8b, that is, the center between the gaps, is generally represented nP (where n=2, 3, ...), and here n=2 and thus the example where the distance is 2P is shown. The number n of head sections of the initial tracking signal recording magnetic head 7 is determined in accordance with the value n of the distance nP in the direction of the arrangement of the tracks between the center of the ~51UQ~3 trace (the center of the gap) of the data signal recording and playback magnetic head 9 and the center between the traces ~the center of the gaps) of the tracking signal playback magnetic heads 8a and 8b, and in this case the number is 2.
As for the initial track:ing signal recording magnetic head 7, positions of the center of the gap, that is, the center of the trace width, and both ends of the head section 7b are indicated on the abscissa ~ with reference to the center ~0 of the gap, that is, the center of the trace width, of the head section 7a which is located adjacent the tracking signal playback magnetic head 8b.
Now, operations of the combination magnetic transducer head apparatus according to the present embodiment will be described. When data signals are to be recorded on a rotating magnetic recording medium 1, at first suitable digital signals are supplied to the initial tracking signal recording magnetic head 7 to effect recording to form two reference tracks at an inner circumferential portion of the rotating magnetic recording medium 1 at a time. Then, a same one of the reference tracks of the rotating magnetic recording medium 1 is reproduced at a time by means of the :~2S~
tracking signal playback magnetic heads 8a and 8b, and the positions of the individual magnetic heads are controlled such that the difference between playback outputs thereof may be reduced to zero, and at the same time data signals are recordecl by means of the data signal recording and playback magnetic head 9. After then, the tracks recorded by the data signal recording and playback magnetic head 9 are reproduced in a similar manner by the tracking signal playback magnetic heads 8a and 8b while at the same time data signals are recorded by the data signal recording and playback magnetic head 9.
On the other hand, upon reproduction, while tracking is aehieved by means of the tracking signal playback magnetic heads 8a and 8b, data signals of a seleeted track are reprodueed by the data signa recording and playbaek magnetie head 9.
Playback signals reproduced from the tracking signal playback magnetie heads 8a and 8b are supplied to respective envelope detect circuits by way of respeetive amplifiers and filters not shown, and outputs of the detection signals of the envelope deteet cireuits are supplied to a differential amplifier. Outpu-t of the differential amplifier is a traeking error signal when ~s~
tracks are scanned, hut is a signal which indicates a position of a rotating magnetic recording medium 1 in its radial direction ~hen the magnetic heads move transversely across tracks. Upon scanning of tracks, positions of the magnetic heads 7, 8a, 8b and 9 in a radial direction of a rotating magnetic recording medium are controlled in response to such a tracking error signal. The differential output of the differential amplifier is supplied to a differential circuit and a zero cross detector. Output of the differential circuit is a signal which indicates a scanning velocity of the magnetic heads when they move transversely across tracks. Output of the zero cross detector is a signal which indicates a numerical value corresponding to the r number of those tracks which are passed by the magnetic heads when the latter move transversely across tracks.
It is to be noted that when tracking of the data signal recording and playback magnetic head 9 is achieved just upon a track T, the center between the traces of the tracking signal playback magnetic heads 8a and 8b is positioned at the center of the width of the track T.
Now, structure of the individual m~gnetic heads described above will be described with reference to ~25~
Figs. 7 and 11 to 13. Referring first to Fig. 9, structure of the data signal recording and playback magnetic head 9 is shown. The data signal recording and playback magnetic head 9 is constituted from a combination thin film type magnetic transducer head including an electromagnetic induction type magnetic transducer head section and a magnetoresistance effect type magnetic transducer head section as described hereinabove. In particularl various elements as hereinafter described are formed on a magnetic substrate 51 by way of a nonmagnetic insulating layer such as of SiO2 not shown. At first, a magnetoresistance effect sensing portion 54 is formed above the magnetic substrate 51 with a gap g left therebetween, and a magnetic layer 56 is formed in a magnetically coupled relationship above the magnetoresistance effect sensing portion 54. The magnetic layer 56 is magnetically directly coupled to a magnetic yoke 52 described below.
A pair of conductive layers 53 and 55 are disposed above and below the magnetic layer 56, respectively. The magnetic yoke 52 is disposed above the magnetoresistance effect sensing portion 54, the magnetic layer 56 and the conductive layer 55, and has one end thereof magnetically directly coupled to the magnetic substrate ~;~5~
51 and the other end thereof located adjacent -the gap g.
Upon reproduction, the magnetic head 9 acts as an magnetoresistance effect type magnetic transducer head, and the conductive layers 53 and 55 are energized with DG currents flowing in mutually opposite directions as perpendicular to the face of the drawing to provide the magnetoresistance effect sensing portion 54 with a bias magnetic field to raise the sensitivity of the latter when data signals are reproduced. On the other hand, upon recording, the magnetic head 9 acts a.s an electromagnetic induction type magnetic head, and the conductive layers 63 and 55 are energized with recording currents flowing in a same direction as perpendicular to the face of the drawing. In this case, the magnetic layer 56 should be passed by little magnetic fluxes. It is to be mentioned here that in Fig. 7, reference symbols 54a and 54b denote each a connecting conductive layer led out from the magnetoresistance effect sensing portion 54, 55a and 55b each a connecting conductive layer led out from the conductive layer 5~, and 53a and 53b each a connecting conductive layer led out from the conductive layer 53.
Structure of the tracking signal playback magnetic head sections 8a and 8b will be described below with ~2S~
reference -to Figs. 7 and 12. The tracking signal playbacls magnetic head sections 8a and 8b are each constituted from a magnetoresistance effect type thin film magnetic transducer head. Several elements are formed on a magnetic substrate 61 by way of a nonmagnetic insulating layer such as of SiO2. A yoke is formed on the magnetic substrate 61 and includes two yoke sections 62a and 62b disposed in a spaced relationship by a predetermined distance from each other. A gap g is defined between one end of the yoke section 62a and one end of the magnetic substrate 61. A
magnetoresistance effect sensing portion 64 and a bias conductive layer 63 below are disposed between the magnetic yoke sections 62a and 62b and the magnetic substrate 61. Thus, a bias magnetic field is provided to the magnetoresistance effect sensing portion 64 so that the sensitivity of the magnetic head sections 8a and 8b may be raised by energizing the bias conductive layer 63 with a DC current. It is to be mentioned that in Fig. 7, reference numerals 64a, 64b and 64c denote connecting conductive layers led out from opposite ends of the magnetoresistance effect sensing portions 64 of the magnetic head sections 8a and 8b, and 63a and 63b denote connecting conductive layers led out from o~
opposite ends of the bias conduc-tive layer 63.
Now, construction of the initial tracking signal recording magnetic head 7 will be described with reference to Figs. 7 and 13. The initial tracking signal recording magnetic head 7 is constituted, in the present embodlment, from an electromagnetic induction type thin film magnetic head as described hereinabove.
Several elements are formed on a magnetic substrate 71 by way of a nonmagnetic insulating layer such as of SiO2. A yoke 72 is formed on the magnetic substrate 71 and has one end thereof magnetically directly coupled to the magnetic substrate 71. A gap g is defined between -the other channel-shaped end of the yoke 72 and one end of the magnetic substrate 71. A conductive layer 73 is located between the yoke 72 and the magnetic substrate 71. Thus, tracking signals can be recorded by energizing the conductive layer 73 with an electric current of recording tracking signals (digital signals).
It is to be mentioned that in Fig. 7, reference symbols 73a and 73b are connecting conductive layers led out from opposite ends of the conductive layer 73.
Another embodiment of a combination magnetic transducer head apparatus according to the present invention will now be described with reference to Fig.
~s~
8. In Fig. 8, like parts or elements are denoted by like reference symbols to those in Fig. 7, and repeated description thereof will be omitted herein. The combination magnetic transducer head apparatus of Fig. 8 also includes a data signal recording and playback magnetic head 9, a pair of tracking signal playback magnetic heads 8a and 8b and a magnetic head 7 for initial formatting. The trace width of each of the magnetic heads is selected in a similar manner to that of the embodiment of Fig. 7. In the arrangement of Fig.
8, the tracking signal playback magnetic heads 8a and 8b are disposed to trace end portions of two adjacent recording tracks to produce tracking signals.
In Fig. 8, positions of the centers and opposite~
ends of gaps of the magnetic heads 7, 8 and 9 are indicated on the abscissa x. In this case, the origin of the abscissa x is at the center of the gap of the data signal recording and playback magnetic head 9. The distance in the direction of the arrangement of tracks between the center of the trace width of the data signal recording and playback magnetic head 9, that is, the origin 0, and the center between the traces of the pair of tracking signal playback magnetic heads 8a and 8b, that is, the center between the gaps, is generally represented (n+l/2)P ( where n=1, 2, 3, ...), and here n=2 and thus the e~ample where the distance is (~/2)P is shown. The quantity or number n+l of head sections of the initial tracking signal recording magnetic head 7 is determined in accordance with the value n of the distance (n+l/2)P in the direction of the arrangement of the tracks between the center of the trace (the center of the gap) of the data signal recording and playback magnetic head 9 and the center between the traces (the center of the gaps) of the tracking signal playback magnetic heads 8a and 8b, and in this case the number is 3.
As for the initlal tracking signal recording magnetic head 7, positions of the center of the gap, that is, the center of the trace width, and both ends of the head sections 7b and 7c are indicated on the abscissa x with reference to the center xO of the gap, that is, the center of the trace width, of the head section 7a which is located adjacent the tracking signal playback magnetic head 8b.
Now, operations of the combination magnetic transducer head apparatus according to the present embodiment will be described. When data signals are to be recorded on a rotating magnetic recording medium 1, :~5C~
at first suitable digital signals are supplied to the initial tracking signal recording magnetic head 7 to effect recording to form three reference tracks at an inner circumferential portion of the rotating magnetic recording medium 1 at a time. Then, inner two of the reference tracks of the rotating magnetic recording medium 1 are reproduced at a time by means of the tracking signal playback magnetic heads 8a and 8b, and the positions of the individual magnetic heads are controlled such that the difference between playback outputs thereof may be reduced to zero, and at the same time data signals are recorded by means of the data signal recording and playback magnetic head 9. After then, the tracks recorded by the data signal recording ~.
and playback magnetic head 9 are reproduced in a similar manner by the tracking signal playback magnetic heads 8a and 8b while at the same time data signals are recorded by the data signal recording and playback magnetic head 9.
On the other hand, upon reproduction, while tracking is achieved by means of the tracklng signal playback magnetic heads 8a and 8b, data signals of a selected track are reproduced by the data signal recording and playback magnetic head 9.
)0~8 Outputs of the tracking signal playback magnetic heads 8a and 8b are used to produce, in a similar manner to that of the arrangement of Fig. 7, a tracking error signal, a velocity signal when the magnetic heads move transversely across tracks, and a servo control signal for recording or reproducing a desired track by signal processing such as counting for jumping over of a number of tracks.
It is to be noted that when tracking of the data signal recording and playback magnetic head 9 is achieved just upon a track T, the center between the traces of the tracking signal playback magnetic heads 8a and 8b is positioned at the center of thé width of the track T. ~
Further, the individual magnetic heads may be any of such heads as shown in Figs. 11 to 13.
Now, a further embodiment of a combination magnetic transducer head apparatus according to the present invention will be desoribed with reference to Figs. 9 and 10.
At first, dimensions of an initial tracking signal recording magnetic head 7 will be described. The pitch PO of head sections 7a, 7b and 7c of the magnetic head 7 is selected to be twice of the pitch of tracks T, that 125~
is, equal to 2P. The trace width of the head sections 7a, 7b and 7c is selected to be equal to the width W of each track T, but it may be a little different from the latter.
Meanwhile, the distance L in a direction of an arrangement of the tracks between the center of the trace width of the data si~nal recording and playback magnetic head 9 and the center between the traces, that is, the center between gaps, of a pair of tracking signal playback magnetic heads 8a and 8b is selected to be three times of the pitch P of the tracks T, that is, to be 3P.
Now, positional relations of the magnetie heads 9 8a, 8b and 7 will be described. Referring to Fig. 9, the direction from the center of a rotating magnetic recording medium 1 to the outer periphery thereof eorresponds to a direetion of the abscissa x indicated by an arrow mark. In the present embodiment, the data signal reeording and playback magnetic head 9 is loeated adjacent the outer periphery of the rotating magnetic recording medium 1 and the initial tracking signal recording magnetic head 7 is located at an innermost position while the traching signal playback magnetic heads 8a and 8b are located inbetween. The combination :~2~;~Q~
magnetic transducer head incl-lding the magnetic heads 7, 8 and 9 is mounted on an end face of the slider 2 as shown in Fig. 2.
Now, operations o the combination magnetic transducer head apparatus according to the present embodiment will be described. When data signals are to be recorded on a rotating magnetic recording medium 1, at first suitable digital signals are supplied to the initial tracking signal recording magnetic head 7 to effect recording to form two reference tracks at an inner circumferential portion of the rotating magnetic recording medium 1 at a time. Then, a same one of the reference tracks of the rotating magnetic recording medium 1 is reproduced at a time by means of the tracking signal playbaek magnetic heads 8a and 8b, and the positions of ths individual magnetic heads are controlled sueh that the differenee between playbaek outputs thereof may be redueed to zero, and at the same time data signals are reeorded by means of the data signal recording and playbaek magnetie head 9. After then, a data traek formed between the referenee traeks and a reference traek are alternately reproduced in a similar manner while at the same time data signals are recorded by means of the data signal recording and ~v~
playbacls magnetic head 9. Thereafter, data tracks recorded one after another are reproduced in a similar manner while at the same time data signals are recorded by the data signal recording and playback magnetic head 9.
In particular, after reference tracks STl, ST2 and ST3 have been recorded at track positions 1, 3 and 5 as shown in Fig. 10 by the initial tracking signal recording magnetic head 7, while the reference tracks STl, ST2 and ST3 are being tracked by the tracking signal playbacls magnetic head 8, data tracks DTl and DT2 are recorded, that is, the data track DTl is formed with reference to the reference track STl at the position 1 and the data track DT2 is formed at a position 6 with reference to the reference track ST2 at the position 3.
After then, data tracks DT3~ DT4, DT5 ... are formed one after another while the data track DTl at the position 4, the reference track ST3 at the position 5, the data track DT3 at the position 6 ... are tracked one after another.
On the other hand, upon reproduction, data signals of a desired track are reproduced by the data signal recording and playback magnetic head 9 while tracking is achieved by the tracking signal playbacls magnetic heads ~zs~
8a and 8b.
In the initial tracking signal recording magnetic head 7 according to the present embodiment, gaps of the head sections 7a, 7b and 7c and clearances between adjacent ones thereof are formed with accurate dimensions particularly because the pitch of the head sections 7a, 7b and 7c of the magnetic head 7 is PO
which is equal to twice of the pitch P of tracks to be formed by ~agnetic recording (thus, Po=2P).
Accordingly, recording of good initial tracking signals is achieYed wi-th an accura-te width of tracks and also with an accurate distance between adjacent tracks.
As apparent from the foregoing description, according to the present invention, a magnetic head for ini-tial formatting is located on a head slider together with a magnetic head for servo control and a magnetic recording and reproducing head. Accordingly, initial formatting can be achie~ed by a magnetic disk system itself without using a specific initial form~tting system, and hence construction can be simplified and a cost therefor can be reduced.
In addition, since initial formatting can be achie~ed by a magnetic disk system itself, no deterioration in accuracy of a positioning ser~o control 3~
~54~8 mechanism will occur due to initialization by a separate initial format-ting sys-te-n as in a conventional technique.
Claims (4)
1. A combination magnetic transducer head apparatus, comprising:
a slider;
a magnetic recording head formed on said slider for writing reference signal tracks on a rotating magnetic recording medium;
the reference signal tracks having a predetermined track pitch P and a predetermined track width W;
a servo control magnetic head formed on said slider; and a magnetic recording and playback head formed on said slider for recording and playback of signals on the magnetic recording medium;
said servo control magnetic head and said magnetic recording and playback head being provided on said slider with such a positional relation that said magnetic recording and playback head records a signal track adjacent one of said reference signal tracks with the predetermined pitch on detecting the reference signal track using said servo control magnetic head.
a slider;
a magnetic recording head formed on said slider for writing reference signal tracks on a rotating magnetic recording medium;
the reference signal tracks having a predetermined track pitch P and a predetermined track width W;
a servo control magnetic head formed on said slider; and a magnetic recording and playback head formed on said slider for recording and playback of signals on the magnetic recording medium;
said servo control magnetic head and said magnetic recording and playback head being provided on said slider with such a positional relation that said magnetic recording and playback head records a signal track adjacent one of said reference signal tracks with the predetermined pitch on detecting the reference signal track using said servo control magnetic head.
2. A combination magnetic transducer head apparatus, comprising:
a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking signal playback magnetic heads mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having a plurality of head sections;
whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium is P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be nP (where n=2, 3, ...), and the quantity or number of said head sections of said initial tracking signal recording magnetic head is selected to be n.
a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking signal playback magnetic heads mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having a plurality of head sections;
whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium is P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be nP (where n=2, 3, ...), and the quantity or number of said head sections of said initial tracking signal recording magnetic head is selected to be n.
3. A combination magnetic transducer head apparatus, comprising:
a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking signal playback magnetic head mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having a plurality of head sections;
whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium is P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be (n+1/2)P (where n=1, 2, 3, ...), and the quantity or number of said head sections of said initial tracking signal recording magnetic head is selected to be n+1.
a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking signal playback magnetic head mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having a plurality of head sections;
whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium is P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be (n+1/2)P (where n=1, 2, 3, ...), and the quantity or number of said head sections of said initial tracking signal recording magnetic head is selected to be n+1.
4. A combination magnetic transducer head apparatus, comprising:
a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking signal playback magnetic head mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having three or more head sections;
whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium is P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to twice of the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be 3P.
a slider disposed in an opposing relationship to a rotating magnetic recording medium and mounted for movement in a radial direction of the rotating magnetic recording medium; and a data signal recording and playback magnetic head mounted on said slider, a pair of tracking signal playback magnetic head mounted on said slider and having a same trace width, and an initial tracking signal recording magnetic head mounted on said slider and having three or more head sections;
whereby, where the pitch of tracks to be formed on the rotating magnetic recording medium is P, the pitch of said plurality of head sections of said initial tracking signal recording magnetic head in a direction of the arrangement of the tracks is selected to be equal to twice of the pitch P of the tracks while the distance in the direction of the arrangement of the tracks between the center of the trace width of said data signal recording and playback magnetic head and the center between the traces of said pair of tracking signal playback magnetic heads is selected to be 3P.
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60045985A JPS61206908A (en) | 1985-03-08 | 1985-03-08 | Magnetic disc device |
| JP45985/85 | 1985-03-08 | ||
| JP87758/85 | 1985-04-24 | ||
| JP60087757A JPS61246912A (en) | 1985-04-24 | 1985-04-24 | Composite magnetic head device |
| JP60087758A JPS61246913A (en) | 1985-04-24 | 1985-04-24 | Composite magnetic head device |
| JP87757/85 | 1985-04-24 | ||
| JP60282325A JPS62141622A (en) | 1985-12-16 | 1985-12-16 | Composite magnetic head unit |
| JP282325/85 | 1985-12-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1250048A true CA1250048A (en) | 1989-02-14 |
Family
ID=27461808
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000503510A Expired CA1250048A (en) | 1985-03-08 | 1986-03-07 | Combination magnetic transducer head apparatus |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4729048A (en) |
| EP (1) | EP0194603B1 (en) |
| KR (1) | KR940005560B1 (en) |
| AU (1) | AU576947B2 (en) |
| CA (1) | CA1250048A (en) |
| DE (1) | DE3685448D1 (en) |
Families Citing this family (38)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5010430A (en) * | 1987-07-30 | 1991-04-23 | Kabushiki Kaisha Toshiba | Head slider arrangement for magnetic disk storage device |
| EP0304695A1 (en) * | 1987-08-17 | 1989-03-01 | Siemens Aktiengesellschaft | Magnetic storage device with a tracking system |
| DE3737452A1 (en) * | 1987-11-04 | 1989-05-18 | Siemens Ag | Magnetic data storage device with a tracking system |
| US4962437A (en) * | 1988-02-24 | 1990-10-09 | Magnetic Peripherals Inc. | Thin film servo head employing the inactive transducer coils to cancel write noise from nearby data heads |
| NL8902570A (en) * | 1989-10-17 | 1991-05-16 | Philips Nv | THIN MOVIE MAGNETIC HEAD. |
| US5073833A (en) * | 1989-11-13 | 1991-12-17 | International Business Machines Corporation | Dual sector servo system for disk file with separate read and write heads |
| JPH03290816A (en) * | 1990-04-06 | 1991-12-20 | Sony Corp | Recording and reproducing device and recording medium thereof |
| JP2935129B2 (en) * | 1990-05-28 | 1999-08-16 | インターナショナル・ビジネス・マシーンズ・コーポレーション | Fixed magnetic disk drive and related apparatus and method |
| US5257149A (en) * | 1991-02-13 | 1993-10-26 | Seagate Technology, Inc. | Disc drive with offset address field |
| TW243530B (en) * | 1992-12-30 | 1995-03-21 | Ibm | Magnetoresistive sensor with improved microtrack profile for improved servo-positioning precision |
| US5485322A (en) * | 1993-03-08 | 1996-01-16 | International Business Machines Corporation | Method and system for writing a clock track on a storage medium |
| US6215606B1 (en) | 1993-03-08 | 2001-04-10 | International Business Machines Corporation | Method and system for determining the widest recording head of a recording device |
| US6700732B1 (en) * | 1993-07-30 | 2004-03-02 | Washington University | Method and apparatus for a vernier magnetic recording head |
| US6301087B1 (en) * | 1994-07-14 | 2001-10-09 | Nomai S.A. | Magneto-resistive removable hard disk cartridge and disk drive and quadrature embedded servo bursts |
| US5488525A (en) * | 1994-08-18 | 1996-01-30 | International Business Machines Corporation | Decoupled magnetic head assembly for quarter-inch tape |
| JPH10501091A (en) * | 1995-03-24 | 1998-01-27 | フィリップス エレクトロニクス ネムローゼ フェンノートシャップ | Magnetic head and system for controlling position of magnetic head |
| KR0182951B1 (en) * | 1995-11-27 | 1999-04-15 | 김광호 | Method and device for auto-writing of servo data for a hard disk drive |
| US5875064A (en) * | 1996-07-09 | 1999-02-23 | International Business Machines Corporation | Method and system for accurate self-servowriting with normalization in a disk drive |
| US5946159A (en) * | 1996-11-27 | 1999-08-31 | International Business Machines Corporation | Servo edge correction using edge samples taken by independently positioned servo elements |
| US5798890A (en) * | 1997-03-05 | 1998-08-25 | International Business Machines Corporation | Disk drive with identical three-element, side-by-side heads on opposite disk surfaces |
| US6104562A (en) * | 1997-04-03 | 2000-08-15 | International Business Machines Corporation | Multiple element transducer for magnetic recording |
| US6088184A (en) * | 1998-06-16 | 2000-07-11 | International Business Machines Corporation | Apparatus and method for the control and positioning of magnetic recording heads in an azimuth recording system |
| JP3934801B2 (en) * | 1998-08-28 | 2007-06-20 | Ｔｄｋ株式会社 | Thin film magnetic head and manufacturing method thereof, and material for thin film magnetic head and manufacturing method thereof |
| US6411459B1 (en) | 1999-02-22 | 2002-06-25 | Seagate Technology Llc | Advanced servo writing method for hard disc drives |
| US6633451B1 (en) * | 1999-04-28 | 2003-10-14 | Hitachi Global Storage Technologies Netherlands B.V. | Self-servo-writing timing pattern generation with non-overlapping read and write elements |
| US6600636B1 (en) | 1999-10-12 | 2003-07-29 | Maxtor Corporation | Magnetic head with write element offset from read element |
| US6865041B1 (en) | 2000-02-29 | 2005-03-08 | Hitachi Global Storage Technologies Netherlands B.V. | Method and apparatus for servowriting using a unipolar write current |
| SG92760A1 (en) * | 2000-03-29 | 2002-11-19 | Fuji Photo Film Co Ltd | Magnetic transfer method and system |
| SG92773A1 (en) * | 2000-03-29 | 2002-11-19 | Fuji Photo Film Co Ltd | Method and apparatus for magnetic transfer |
| SG92774A1 (en) * | 2000-03-29 | 2002-11-19 | Fuji Photo Film Co Ltd | Method and apparatus for magnetic transfer |
| SG92772A1 (en) * | 2000-03-29 | 2002-11-19 | Fuji Photo Film Co Ltd | Method and apparatus for magnetic transfer |
| JP2004022022A (en) * | 2002-06-13 | 2004-01-22 | Fuji Photo Film Co Ltd | Magnetic head |
| JP2004030777A (en) * | 2002-06-25 | 2004-01-29 | Internatl Business Mach Corp <Ibm> | Data storage device, recording medium, servo write method and data reading and writing method |
| US7474488B2 (en) * | 2005-08-30 | 2009-01-06 | International Business Machines Corporation | Magnetic head, tape drive system, and method |
| TWI287318B (en) * | 2005-12-07 | 2007-09-21 | Ind Tech Res Inst | Radio frequency identification (RFID) antenna and fabricating method thereof |
| US9245556B2 (en) * | 2014-03-10 | 2016-01-26 | Western Digital Technologies, Inc. | Disk drive employing multiple read elements to increase radial band for two-dimensional magnetic recording |
| US9070406B1 (en) | 2014-03-10 | 2015-06-30 | Western Digital Technologies, Inc. | Disk drive configuring one-dimensional and two-dimensional recording areas based on read element spacing |
| US11929104B2 (en) * | 2022-02-18 | 2024-03-12 | Seagate Technology Llc | Data storage drive with dedicated erase transducer |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2299694A1 (en) * | 1975-01-31 | 1976-08-27 | Ibm | DEVICE FOR ACCESSING THE TRACKS OF A RECORDING MEDIUM SUCH AS A MAGNETIC DISC |
| US4007493A (en) * | 1975-05-06 | 1977-02-08 | Burroughs Corporation | Track positioning system for magnetic transducer head |
| US4068268A (en) * | 1976-01-08 | 1978-01-10 | Idemoto Tom Y | Method and apparatus for writing servo-tracks on rotating magnetic memory surfaces |
| JPS53138314A (en) * | 1977-05-09 | 1978-12-02 | Fujitsu Ltd | Magnetic recording system |
| JPS56119918A (en) * | 1980-02-22 | 1981-09-19 | Nec Corp | Magnetic disc memory device |
| JPS6074116A (en) * | 1983-09-29 | 1985-04-26 | Hitachi Ltd | Magnetic recording medium |
| US4613915A (en) * | 1985-10-16 | 1986-09-23 | International Business Machines Corporation | Twin track vertical magnetic recording servo control method and apparatus with offset voltage compensation |
-
1986
- 1986-03-05 AU AU54390/86A patent/AU576947B2/en not_active Ceased
- 1986-03-07 EP EP86103043A patent/EP0194603B1/en not_active Expired - Lifetime
- 1986-03-07 DE DE8686103043T patent/DE3685448D1/en not_active Expired - Lifetime
- 1986-03-07 CA CA000503510A patent/CA1250048A/en not_active Expired
- 1986-03-08 KR KR1019860001651A patent/KR940005560B1/en not_active IP Right Cessation
- 1986-03-10 US US06/837,810 patent/US4729048A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0194603B1 (en) | 1992-05-27 |
| DE3685448D1 (en) | 1992-07-02 |
| AU5439086A (en) | 1986-09-11 |
| US4729048A (en) | 1988-03-01 |
| EP0194603A2 (en) | 1986-09-17 |
| KR940005560B1 (en) | 1994-06-20 |
| KR860007632A (en) | 1986-10-15 |
| AU576947B2 (en) | 1988-09-08 |
| EP0194603A3 (en) | 1989-06-28 |
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