JP2942289B2 - Magnetic disk drive and magnetic disk processing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk processing method, a magnetic disk, and a magnetic disk device, and more particularly, to a decrease in positioning accuracy due to a processing flaw generated in surface processing of a magnetic disk. It relates to technology suitable for measures such as.

[Conventional technology]

For example, a magnetic disk device used as an external storage device in an electronic computer system or the like has a magnetic head movably opposed to a surface of a disk-shaped magnetic disk that rotates at a high speed, and a radial displacement of the magnetic head causes By positioning the magnetic head at any one of a plurality of tracks (information recording areas) concentrically provided about the center of rotation of the magnetic disk, information recording / reproducing operations can be performed via the magnetic head. It has become.

By the way, the recording density of information on a magnetic disk is
In general, the gap is in inverse proportion to the gap between the magnetic disk and the magnetic head.Therefore, the gap is steadily becoming smaller, and irregularities on the surface of the magnetic disk may cause damage to the magnetic disk and the magnetic head, or damage to the magnetic disk. This will cause a fatal obstacle such as destruction of data recorded in the data.

For this reason, in the manufacturing process of the magnetic disk, it is essential to perform a surface finishing process for flattening the surface of the disk material constituting the magnetic disk and the magnetic film adhered to the disk material to a desired accuracy.

Conventionally, such processing techniques include, for example, JP-A-57-64332, JP-A-62-170022, and
As described in Japanese Patent Application Laid-Open No. 9-107722 and the like, while supporting and rotating the magnetic disk coaxially, a wrapping tape wider than the radial width of the information recording area on the magnetic disk is pressed at one time. The processing method has been generally performed with a short processing time.

By the way, since the abrasive material constituting the wrapping tape is an aggregate of abrasive grains, the abrasive material is coated on the material disk or the material disk due to uneven particle size, contamination of impurities, and clogging of the abrasive particles. It is known that a scratch having a width of about several μm and a length of several mm to several tens mm is generated on the surface of the deposited magnetic film.

That is, this scratch is a surface of the material disk, or a magnetic material film adhered to the surface is locally cut off more deeply than other normal processing regions, and the above-mentioned conventional scratch is used. In the processing method, a magnetic disk that rotates during the processing has an arc shape that is substantially concentric with the rotation center of the magnetic disk.

[Problems to be solved by the invention]

When a magnetic disk having a scratch obtained by the conventional processing technique as described above is mounted on an actual magnetic disk device, the positioning accuracy of the magnetic head with respect to tracks arranged concentrically on the magnetic disk is reduced. There is.

That is, in many magnetic disk devices, in order to cause a magnetic head to accurately follow a target track, position information is written on one of the recording surfaces of a plurality of magnetic disks fixed coaxially and parallel to a rotary drive. FIG. 11 shows an example of a positioning signal recorded on the servo surface.

A plurality of tracks concentrically arranged on the servo surface have different read signals a and b from each other.
ODD pattern and EVEN patterns cause is written alternately at a track pitch l _P. The combined signal c of the read signals a and b is read by the servo head HS having a core width l _hs extending over the adjacent tracks A and B, and the servo head HS is moved in the radial direction so that the levels of both signals are equal. Feedback control is performed.

Therefore, in a normal state, the servo head is controlled such that the center of the core width follows the boundary between the adjacent tracks A and B.

As shown in FIG. 12, for example, a scratch 40 having a width w concentrically with the track A is formed on a part of such a servo surface by the conventional processing method described above.
When 2 is present, the composite signal c ₁ which is read by the servo head HS passing through the region by the width of of the scratch 402, a state in which the output level of the read signal a is lowered by Delta] v. Then, the feedback control system which detects this causes the servo head HS to move to the track A side by Δx = w / 2 so as to correct this Δv so as to become the composite signal c _2. Is shifted from the original position by Δx, and the waveform of the composite signal c ₂ at that time is the same as the waveform of the composite signal c in the normal state. There was a problem that the shift could not be recognized.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic disk processing method capable of preventing a decrease in positioning accuracy due to a scratch or the like generated during processing.

Another object of the present invention is to provide a magnetic disk capable of realizing a high recording density and improving the yield without being affected by scratches or the like generated during surface processing.

It is another object of the present invention to provide a magnetic disk device having high reliability in information recording / reproducing operations.

The above and other objects and novel features of the present invention are as follows.
It will be apparent from the description of this specification and the accompanying drawings.

[Means for solving the problem]

The outline of a typical invention disclosed in the present application is briefly described as follows.

That is, the method for processing a magnetic disk according to the present invention includes:
A method for processing a magnetic disk in which information is recorded in concentric regions arranged on a recording surface formed by applying a magnetic film to a surface of a disk material, wherein at least one surface of the disk material and the magnetic material film The processing locus in the processing intersects the concentric circle region.

In addition, the magnetic disk drive according to the present invention includes a method for processing at least one of a magnetic disk having a servo surface on which position information is recorded and a magnetic disk having a data surface on which normal data is recorded by using the above-described magnetic disk processing method. It was manufactured using

Further, according to the magnetic disk drive of the present invention, in a magnetic disk drive of a data surface servo system in which positional information and normal data are mixedly recorded on the same recording surface of the magnetic disk, On which a magnetic disk manufactured by using the above method is mounted.

[Action]

According to the magnetic disk processing method of the present invention described above,
Scratch at the time of processing occurs in a state where it crosses a concentric area where position information, data, etc. are recorded,
For the reasons described below, it is possible to prevent a decrease in the positioning accuracy of the magnetic head with respect to the magnetic disk and a decrease in the reliability of the data recording / reproducing operation due to the presence of the scratch.

That is, the recording surface of the magnetic disk track pitch l track group that position information is recorded in _P (second concentric region) is arranged, as shown for example in Figure 4, the angle theta ₁ to the track group _Are considered, and a case where this position information is read out by the servo head HS having the core width l _hs is considered.

In this case, the position signal obtained by demodulating the output from the servo head HS generates a positional shift amount w / 2 in period t, the frequency f ₁ from the period t is obtained by the following equation (5).

f ₁ = 1 / t = rω · tan θ ₁ / l _hs (5) where r: track radius ω: rotational angular velocity of the magnetic disk l _hs : core width of the servo head θ ₁ : connection between the track and the scratch Since the positioning servo system of the magnetic head generally used in the magnetic disk drive includes a mechanical operation part, it cannot follow the disturbance of the position signal at a certain frequency or more, The positioning accuracy of the magnetic head does not substantially decrease.

In a normal magnetic disk drive, this frequency is 2
It is about 5kHz. Therefore, the equation (5) to the intersection angle theta ₁ or more frequency f ₁ is about 2~5kHz of, by setting the intersection angle of the machining path and the concentric regions (tracks), if scratches are generated during processing Even so, a decrease in positioning accuracy can be prevented.

Further, as shown in FIG. 5, when the normal data scratches are formed to cross at an intersection angle theta ₂ to the track group to be recorded (concentric regions), the data head HD
, The reproduction output in the intersection area decreases, and the frequency f ₂ is expressed by the following equation (6).

f ₂ = 1 / t = rω · tanθ ₂ / l _hd (6) where l _{hd is} the core width of the data head. Normally, in a magnetic disk device, automatic gain control is performed to eliminate output fluctuations in the data head HD. The output fluctuation is prevented by using an amplifier.

Therefore, the frequency f ₂ of the output fluctuation is equal to or less than the response frequency of the automatic gain control amplifier, the output variation of the data head HD does not occur.

The response frequency of an automatic gain control amplifier of a data read system in a general magnetic disk device is about 100 kHz. Accordingly, by controlling the angle of intersection between the formula so that the frequency f ₂ of the output fluctuation as indicated by (6) is crossing angle theta ₂ below to be about 100kHz, processing locus concentric regions (track group), even if Even if there is a scratch, it is possible to prevent a change in the read output of the data head HD.

In addition, the cross-sectional shape of the disk material after cutting or the like is in an uneven state shown in FIG. 3, for example, and the thickness of the magnetic film deposited on the surface changes according to the processed cross-sectional shape. On the other hand, the writing of information on the magnetic film of the magnetic disk is a so-called saturation write, and therefore, the reproduction output is large in a thick portion of the magnetic film and small in a thin portion.

Accordingly, smaller and processing locus in the disc material, than the intersection angle theta ₁ which the crossing angle of concentric regions (track groups) disposed in magnetic film is deposited on the surface thereof is obtained from the formula (5) If this happens, it causes a reduction in the reproduction output of the position information in the servo head HS, and the head positioning accuracy deteriorates. In addition, in the data head HD, this is one of the factors that impairs the reliability of the data reproducing operation.

Further, the above-mentioned situation is not limited to the finish processing for flattening the surface of the disk material and the magnetic film adhered to the surface of the disk material, and for example, an excessively flat magnetic material formed by sputtering or the like. The same applies to a surface roughening process (texture process) performed to prevent the head adsorption phenomenon on the film.

Therefore, in the magnetic disk processing method of the present invention, for example, a processing locus is spirally formed by moving a processing tool against a rotating magnetic disk or the like while moving the processing tool in a radial direction, or a magnetic disk or a disk. By pressing the machining tool while rotating the material while being eccentric from the rotation center (center of the concentric region) in actual use, the machining trajectory is made to intersect the concentric region. By controlling the ratio between the rotation speed of the magnetic disk or the like and the feed speed of the tool in the radial direction or the amount of eccentricity of the magnetic disk during processing to a desired value, the intersection angle θ ₃ between the processing locus and the concentric area is controlled. Is θ
By satisfying the relationship of ₁ <θ ₃ <θ _2, it is possible to reliably prevent the positioning accuracy and the reliability of the data recording / reproducing operation from being lowered due to scratches inevitably generated during processing.

Further, in a magnetic disk manufactured by such a processing method, the scratches present on the magnetic disk do not substantially cause a fatal product defect, so that the information recording density and the yield of the magnetic disk are improved.

Further, in the magnetic disk device of the present invention, when positioning information and data are arranged on different recording surfaces, or when positioning information and data are mixed and recorded on the same recording surface, Because the magnetic disk to be mounted is manufactured by the above processing,
Positioning accuracy and reliability in data recording / reproducing operations are improved.

Embodiment 1 Hereinafter, a magnetic disk processing method and an example of a magnetic disk device according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing an example of a configuration of a processing apparatus for performing a magnetic disk processing method according to an embodiment of the present invention. FIG. 2 is a perspective view illustrating an example of the operation thereof. FIG. 8 is a sectional view showing an example of the configuration of a magnetic disk drive on which a magnetic disk processed by the processing device is mounted.

First, an example of the configuration of the magnetic disk drive of the present embodiment will be described with reference to FIG.

A rotary drive shaft 3 that is driven to rotate by a motor 2 is provided inside the housing 1, and a plurality of magnetic disks 4 are parallel to and coaxial with each other at a predetermined interval on the rotary drive shaft 3. Fixed.

The magnetic disk 4 has, for example, a structure in which a magnetic film 401 is adhered to the surface of a disk material 400 that has been subjected to predetermined surface processing.
The surface processing of 01 is performed by a processing method described later.

One of the plurality of recording surfaces of the plurality of magnetic disks 4 is used as a servo surface 4a, and a plurality of concentric tracks (not shown) whose centers coincide with the rotation center of the magnetic disk 4 are used for positioning information. Is recorded. The other recording surface is used as a data surface 4b on which normal data is recorded on a plurality of concentrically provided tracks.

A carriage 5 that is movable in the radial direction of the magnetic disk 4 is provided on the side of the plurality of magnetic disks 4 and is mounted on a rail 5a fixed to the housing 1 via a plurality of bearings 5b. It is slidably mounted.

A coil 5c is fixed to the carriage 5 and moves inside a yoke 5d made of a permanent magnet or the like which is fixed to the housing 1 and forms a magnetic circuit, so that the voice coil motor VCM is moved together with the yoke 5d. Is composed.

By appropriately controlling the energizing direction and energizing amount of the coil 5c, the displacement direction and the displacement speed of the carriage 5 in the radial direction of the magnetic disk 4 are controlled.

A plurality of head arms 6 are fixed to the side of the carriage 5 facing the plurality of magnetic disks 4 on the opposite side of the coil 5c so that the leading ends are located in the gaps between the plurality of magnetic disks 4.

At the tip of the head arm 6, a plurality of magnetic disks 4
A plurality of magnetic heads 7 are supported via leaf springs 6a so as to face each of the recording surfaces of the magnetic heads 7. Of these magnetic heads, the one corresponding to the servo surface 4a is a servo head 7a for reading position information. The other that functions as the (HS) and faces the data surface 4b functions as the data head 7b (HD) that performs a normal data recording / reproducing operation.

The servo head 7a has a demodulation circuit 8 for demodulating a position signal read from the servo head 7a into a position signal.
, A compensation circuit 9 and a power amplifier 10 for supplying a drive current to the coil 5c are connected to form a servo loop.

Then, for example, the carriage 5 is controlled so that the radial displacement of the servo surface 4a of the servo head 7a from the target track becomes zero, and thereby a plurality of data supported by the carriage 5 are controlled. The operation of following the target track on the data surface 4b of the head 7b is performed.

The data head 7b is connected to an upper position (not shown) via a preamplifier 11, an automatic gain control amplification (AGC) circuit 12, a data discrimination circuit 13, a data recording system circuit (not shown), and the like, and It performs modulation / demodulation, amplification, error correction processing, and the like of data exchanged between them.

On the other hand, a processing apparatus for processing the surface of the magnetic disk 4 mounted on the magnetic disk device of the present embodiment as described above, for example, as shown in FIG. 1, detachably holds the magnetic disk 4 to be processed. Chuck 20 for rotating the magnetic disk 4 via the chuck 20
21.

Further, a linear way mechanism 22 that is movable in the radial direction of the magnetic disk 4 held by the chuck 20 is provided near the rotation drive mechanism 21, and is driven by a feed motor 22a.

The linear way mechanism 22 includes two pairs of a pull-out pulley 23, a take-up pulley 24, a pull-out pulley 25, and a take-up pulley 2, which are paired with each other so as to sandwich the magnetic disk 4.
6 are supported, each having a plurality of motors 23a, 24a, 25
a, 26a.

A wrapping tape 27 and a wrapping tape 28 are provided between the feeding pulley 23 and the winding pulley 24 and between the feeding pulley 25 and the winding pulley 26, respectively.
Is stretched and a pressure roller is placed in the middle of the path.
The magnetic disk 4 is pressed against both the front and back surfaces of the magnetic disk 4 by a pressure roller 29 and a pressure roller 30, respectively.

The rotation drive mechanism 21 that drives the magnetic disk 4 held by the chuck 20 is controlled by an angular velocity control unit 31.

Also, a feed motor 22a that drives the linear way mechanism 22
Is controlled by a tape feeding speed control unit 32, and motors 24a, 26a and motors 23a, 25a for driving the winding pulleys 24, 26 and the feeding pulleys 23, 25 are controlled by a tape winding speed control unit 33.

Hereinafter, an example of a method of processing a magnetic disk in the present embodiment and an operation of a magnetic disk device using the same will be described.

First, the magnetic disk 4 is held on the chuck 20 at a predetermined rotation speed so that the rotation center in actual use mounted on the rotation drive shaft 3 of the magnetic disk device coincides with the rotation center of the chuck 20. Rotate with.

Then, as shown in FIG. 2, the linear way mechanism 22 is operated while the wrapping tapes 27 and 28 are pressed against both surfaces of the rotating magnetic disk 4 by the pressure rollers 29 and 30, so that the magnetic disk The surface of the magnetic film 401 constituting 4 is polished by the wrapping tapes 27 and 28, and the processing locus at this time becomes spiral.

Therefore, during the processing, scratches that occur accidentally due to, for example, the magnetic film 401 being cut excessively deeper than other normal processing regions, cause the magnetic disk 4 to be damaged when mounted on the magnetic disk device. The state intersects a plurality of track groups arranged concentrically around the rotation center.

Here, in the case of the present embodiment, the angular velocity ω of rotation of the magnetic disk 4 held by the chuck 20 by the rotation drive mechanism 21 and the linear way mechanism 22 of the magnetic disk 4 of the wrapping tapes 27 and 28 the relationship between the movement (feed) velocity V ₁ in the radial direction is set for example as follows.

That is, as an example of the specification of the magnetic disk 4 and the magnetic disk device on which the magnetic disk 4 is mounted, for example, the servo surface 4a
The minimum write radius of the positioning signal is 90 mm, the maximum write radius of the data signal on the data surface 4b is 110 mm, the track pitch is 20 μm, the required frequency of the servo system is 5 kHz or more,
When the required frequency in the AGC circuit 12 connected to the data head 7b is set to 100 kHz or less, the processing locus and the track group arranged concentrically on the servo surface of the magnetic disk 4 so that the scratch does not deteriorate the positioning accuracy. The minimum intersection angle θ ₁ is obtained from the above equation (1), and θ ₁ = 0.
34 degrees. Incidentally, showing the theta ₁ of calculation results under various conditions in Figure 6.

Further, for the scratch in the data surface 4b is not adversely affect the detection level of the data signal, the maximum crossing angle theta ₂ is approximated by the above formula _(2), θ 2 ₌ 2.8
Degree. FIG. 7 shows the calculation results of θ ₂ under various conditions.

Therefore, when processing the magnetic disk 4 mounted on the magnetic disk device having the above-described specification, the spiral processing trajectory at the time of processing and the concentric area (the track group on the servo surface 4a and the data surface 4b) are formed. the crossing angle theta _3, 0.34 <
What is necessary is just to set it in the range of (theta) ₃ <2.8.

Assuming that the number of revolutions N at the time of processing the magnetic disk 4 held by the chuck 20 is, for example, 1000 rpm, the angular velocity ω becomes 10.5 rad / sec from ω = 2πN / 60. At this time the wrapping tape 27 and 28, feed speed V ₁ in the radial direction of the magnetic disk 4, Motomari from the equation (3), if _{V 1 = 5.6~56mm / sec, 0.34} <θ 3 <2.8 in Can meet your requirements.

In addition, the width W _T of the wrapping tapes 27 and 28 is set so that W _T ≧ V ₁
If it is set as × 2π / ω, no unprocessed portion occurs.

By mounting the magnetic disk 4 which has been subjected to the surface processing under such conditions, even if a scratch occurs during the processing, the magnetic disk device can read the position information read from the servo surface 4a of the magnetic disk 4, for example. This prevents the positioning accuracy from being lowered due to the variation due to the scratches, and does not cause a large drop in the read output of the data signal from the data surface 4b.

As a result, the recording density is improved by further narrowing the track group concentrically arranged on the servo surface 4a and the data surface 4b of the magnetic disk 4, and the reliability of the information recording / reproducing operation in the magnetic disk device is improved. An improvement can be realized.

In the above description, the case of processing the surface of the magnetic film 401 on the surface of the magnetic disk 4 has been described, but the same applies to the surface processing of the disk material 400 serving as the base.

That is, by setting the relationship between the rotation speed of the disk material 400 during processing and the feed speed in the radial direction of the cutting tool so as to satisfy the above-described conditions, a spiral shape is generated on the surface of the disk material 400. The region where the thickness of the magnetic film 401 fluctuates due to the irregularities intersects with the track group concentrically arranged on the magnetic film 401 at an appropriate crossing angle, so that the magnetic film 40
It is possible to avoid a decrease in the reproduction output of the position signal and the data signal in the thin portion of 1.

Furthermore, when the magnetic film 401 is formed on the disk material 400 by, for example, a method such as sputtering or plating, the magnetic film 401 becomes excessively flat, and for example, a contact start / stop ( In a CSS) type magnetic disk drive, the servo head 7a and the data head 7b are stuck to the servo surface 4a and the data surface 4b due to the action of a lubricant applied to the surface of the magnetic disk 4 and are difficult to start. May cause.

Therefore, to avoid this, an excessively flat magnetic film
Texture processing for intentionally roughening the surface of the surface 401 to a predetermined state is performed. In this texture processing, too, the rotation speed of the magnetic disk 4 and the feed speed in the radial direction of the wrapping tape are changed. By setting so as to satisfy the above conditions, even if scratches occur during texture processing, adverse effects on positioning accuracy, reproduction output, and the like can be prevented.

Further, usually, in the manufacturing process of the magnetic disk drive, the servo surface is set in a state as shown in FIG.
Generally, writing of position information to 4a is performed to perform a final inspection for the presence or absence of a defect in the magnetic disk 4.

If a defect due to scratches or the like is found at that time, it is necessary to disassemble the plurality of magnetic disks 4 that have been assembled and to assemble another normal magnetic disk 4 again. However, in the case of the present embodiment, even if a scratch is present, as described above, erroneous reading of the position information from the servo surface 4a and a decrease in the reading level of the position signal and the data signal are substantially caused. As a result, unnecessary assembly and disassembly work due to the presence of scratches on the magnetic disk 4 becomes unnecessary, and productivity in the manufacturing process of the magnetic disk device is greatly improved.

Embodiment 2 FIG. 9 is an explanatory view showing an example of a magnetic disk processing method according to another embodiment of the present invention.

In the case of the second embodiment, the rotation center of the magnetic disk 4 that is rotated during processing, that is, the processing center 400B, is applied to the magnetic disk device of the magnetic disk 4 in the surface finishing after the formation of the magnetic film 401. It is set at a point decentered in any direction by a predetermined amount ΔY from the center 400A (that is, the center of the concentrically arranged track group) in the mounted actual use state.

As a result of performing such eccentric processing, a processing mark or scratch remaining on the surface of the magnetic disk 4 becomes, for example, a scratch 402 indicated by a broken line.

FIG. 10 shows that the magnetic disk processed as described above is mounted without being eccentric on the magnetic disk device as a servo disk on which the servo surface 4a is formed.
FIG. 9 is an explanatory diagram showing a state where position information is written without eccentricity.

A part of the scratch 402 crosses the track 403 at an angle θ determined according to the eccentricity ΔY.

Servo head 7a (H
The position signal 404 demodulated from the position information read by S) includes the position signal 404 during the time when the scratch 402 intersects with the servo head 7a moving on the track 403, that is, during the head core passage time ΔT. A pair of positive and negative position erroneous detection amounts ΔX are generated.

Then, by appropriately setting the value of the eccentric amount [Delta] Y, can be smaller than the response available time T _s of the servo control system of the head core passing time ΔT in the magnetic disk device, due to the presence of the scratch 402 Position error detection amount ΔX
It is possible to prevent the servo head 7a from following up accidentally.

On the other hand, if the value of the eccentric amount ΔY during processing is set to be larger than necessary, the following inconvenience occurs.

That is, in the magnetic disk device, usually, the detection sensitivity of the position signal is made uniform regardless of the position of the magnetic disk.
Automatic gain control (AGC) is performed to keep the sum of the D component and the EVEN component constant.

When the amount of eccentricity ΔY is set to be large, the head-core passage time ΔT becomes small as described above, and this ΔT
There below the response available time T _a of the AGC control system can no longer AGC control processing of a position information read signal, it produces an adverse effect that the position detection sensitivity in the head core passing time ΔT is reduced.

Thus, the head core passing time ΔT is shorter than the response available time T _s of the servo control system, and it is necessary to set longer than the response available time T _a of the AGC control system.

In many magnetic disk drives, ΔT _s is about 1 ms and T
_{Since a} is set to about 10 μs, the settable range of ΔT satisfying the above condition is sufficiently wide.

Further, the magnetic disk 4 subjected to the eccentric processing as in this embodiment can be used not only as a servo disk but also as a data disk used for recording / reproducing normal data.

That is, a reproduced signal read from a data disk usually includes an AG that keeps the amplitude of the reproduced signal constant.
C control is performed. A in such a data reproduction system
This is because the response time _Td of the GC control system is about several μs, and the head core passage time ΔT in the magnetic disk 4 subjected to the eccentric processing as in this embodiment is sufficiently larger than _Td .

Thus, by setting the eccentricity ΔY during processing to a range that satisfies the above-described condition, for example, even when the magnetic disk 4 is selectively used for a servo disk and a data disk, each magnetic disk 4 has its own eccentricity ΔY. There is an advantage that there is no need to provide individual processing steps, and processing equipment and the like can be simplified.

In the magnetic disk drive, the magnetic disk 4
In the same recording surface, the position information is discretely or continuously written together with normal data in advance, and this position information is read out during actual use, demodulated into a position signal, and the off-track correction or track following is performed. Although there is a data surface servo method that performs the operation itself, the processing method of the present embodiment is applied to a magnetic disk mounted on a magnetic disk device of the data surface servo method. The effect of preventing the deterioration of the positioning accuracy is obtained.

The processing method of the present embodiment is applicable not only to the surface finishing of the magnetic film 401 constituting the magnetic disk 4 but also to the texture processing of the magnetic film 401 formed to be excessively flat by a method such as sputtering or plating. Needless to say, the same effect can be obtained.

Although the invention made by the inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments, and it is needless to say that various changes can be made without departing from the gist of the invention. Nor.

〔The invention's effect〕

The effects obtained by typical aspects of the invention disclosed in the present application will be briefly described as follows.

That is, the method for processing a magnetic disk according to the present invention includes:
A method for processing a magnetic disk in which information is recorded in concentric regions arranged on a recording surface formed by applying a magnetic film to a surface of a disk material, wherein at least one of the disk material and the magnetic film Since the machining trajectory in the surface machining crosses the concentric area, for example, the machining trajectory may be formed in a spiral shape by pressing the machining tool against a rotating magnetic disk or the like while moving the machining tool in the radial direction. The eccentricity of the machining trajectory by pressing the machining tool while rotating the magnetic disk or disk element while eccentrically rotating from the center of rotation (the center of the concentric area) in actual use makes the machining trajectory relative to the concentric area. And the ratio between the rotation speed of the magnetic disk and the feed rate of the tool in the radial direction, or the amount of eccentricity of the magnetic disk during machining is determined. By controlling the value, the crossing angle theta ₃ of the machining locus concentric regions, the aforementioned θ _{1 <θ 3}
<So as to satisfy the theta ₂ the relationship, it is possible to reliably prevent a decrease in reliability of the inevitably recording and reproducing operation of the positioning accuracy and data resulting from the scratches that occur during processing.

Further, in the magnetic disk manufactured by the above-described processing method, the scratch existing on the magnetic disk does not substantially cause a fatal product defect, so that the information recording density and the yield of the magnetic disk are improved.

Further, in the magnetic disk device of the present invention, when positioning information and data are arranged on different recording surfaces, or when positioning information and data are mixed and recorded on the same recording surface, Because the magnetic disk to be mounted is manufactured by the above processing,
Positioning accuracy and reliability in data recording / reproducing operations are improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of the configuration of a processing apparatus for performing a magnetic disk processing method according to an embodiment of the present invention, FIG. 2 is a perspective view illustrating an example of its operation, FIG. Is a cross-sectional view showing an example of the structure of a magnetic disk, FIG. 4 is a diagram illustrating the operation of a magnetic disk processing method according to an embodiment of the present invention, and FIG. FIG. 6, FIG. 6 is a diagram for explaining the operation, FIG. 7 is a diagram for explaining the operation, and FIG. 8 is an example of the configuration of a magnetic disk drive according to an embodiment of the present invention. FIG. 9 is an explanatory view for explaining an example of a method of processing a magnetic disk according to an embodiment of the present invention, FIG. 10 is an explanatory view for explaining an example of its operation, FIG. FIG. 12 is a diagram showing an example of a method of writing position information in a general magnetic disk drive, Is a diagram illustrating an example of a defect in the conventional processing methods. 1 ... housing, 2 ... motor, 3 ... rotary drive shaft, 4 ...
Magnetic disk, 4a ... servo surface, 4b ... data surface, 5 ...
… Carriage, 5a …… rail, 5b …… bearing, 5c…
... Coil, 5d ... Yoke, 6 ... Head arm, 6a ...
Leaf spring, 7 Magnetic head, 7a Servo head (H
S), 7b: Data head (HD), 8: Demodulation circuit, 9
Compensation circuit, 10 Power amplifier, 11 Preamplifier, 12 AGC circuit, 13 Data discrimination circuit, VCM Voice coil motor, 20 Chuck, 21 Rotary drive mechanism, 22 … Linear way mechanism, 22a …… Feed motor, 23,
25 …… Pull out pulley, 23a, 25a …… Motor, 24,26 ……
Take-up pulley, 24a, 26a Motor, 27, 28 Wrapping tape, 29, 30 Pressure roller, 31 Angular speed control unit 32 Tape feed speed control unit 33 Tape winding Picking speed control unit, 400: disk material, 401: magnetic film,
402: scratch, 403: track, 404: position signal, 400A: center in actual use (center of concentric track group), 400B: center of rotation during processing.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiaki Kojima 2880 Kozuhara, Kozuhara-shi, Kanagawa Prefecture Inside the Odawara Plant, Hitachi, Ltd. 56) References JP-A-63-160010 (JP, A) JP-A-63-300426 (JP, A) JP-A-2-134727 (JP, A) JP-A-2-158916 (JP, A) Hei 2-297722 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) G11B 5/84 G11B 5/82

Claims (5)

(57) [Claims] A recording surface is formed by applying a magnetic film on the surface of a disk material, and a first concentric region where a normal data signal is recorded and a first concentric region where a positioning signal is recorded in advance. A magnetic disk in which a second concentric area different from the concentric area is arranged on the recording surface; a rotation drive unit that supports and rotates the magnetic disk coaxially with the first and second concentric areas; A head having a first function of recording / reproducing a normal data signal to / from a concentric region of the head; a head having a second function of reading the positioning signal from the second concentric region; A head is supported so as to be displaceable in a radial direction of the magnetic disk, and the first function is performed based on the positioning signal obtained from the second concentric region via the head having the second function. And a positioning mechanism for controlling positioning of the head with respect to the first concentric region, wherein a processing locus in surface processing of at least one of the disk material and the magnetic film intersects the concentric region. It has a magnetic disk, the second concentric region, the value crossing angle theta ₁ between processing locus in the surface processing for the magnetic disk to which the second concentric region is disposed is represented by the following formula (1) A magnetic disk drive characterized by the above. θ ₁ = tan ⁻¹ (fa · l _hd2 / r _min · ω) (1) where fa: minimum required frequency of the positioning signal, l _hd2 : core width of the head having the second function, r _min : Minimum writing radius of positioning signal, ω: Rotational angular velocity of magnetic disk. 2. An automatic gain control amplifier is connected to the head having the first function, and an intersection angle .theta. Of a processing locus in a surface processing on a concentric region of the magnetic disk is equal to or more than the value of the expression (1). And a magnetic disk that has been subjected to surface processing so as to have an intersection angle θ ₂ or less represented by the following equation (2) is used as a magnetic disk in which the first concentric region and the second concentric region are respectively arranged. 2. The magnetic disk drive according to claim 1, wherein the magnetic disk drive is used. θ ₂ = tan ⁻¹ (fb · l _hd1 / r _max · ω) (2) where fb is the response frequency of the automatic gain control amplifier of the readout system, and l _{hd1 is} the core of the head having the first function. Width, r _max : maximum write radius of data signal, ω: rotational angular velocity of the magnetic disk. 3. A method of processing a magnetic disk in which information is recorded in a concentric area arranged on a recording surface formed by applying a magnetic film to a surface of a disk material, wherein the information is processed on a rotating magnetic disk surface. Pressing the tool, the rotation speed V _{2 of the} magnetic disk
And an intersection angle θ ₃ obtained from the moving speed V _{1 of the} processing tool in the radial direction of the magnetic disk based on the following equation (3).
A magnetic disk processing method in which a surface of the magnetic film is processed by drawing a spiral processing locus such that the value of the following equation (4) is satisfied. θ ₃ = tan ⁻¹ (V ₁ / V ₂ ) (3) θ ₁ <θ ₃ <θ ₂ (4) where θ ₁ : a value obtained from the equation (1), θ ₂ : Value obtained from equation (2). 4. A recording surface is formed by applying a magnetic film on the surface of a disk material, and a first concentric area in which a normal data signal is recorded and a second concentric circle in which a positioning signal is recorded in advance. A magnetic disk having an area arranged on the same recording surface; a rotation drive unit for supporting and rotating the magnetic disk; and a first function of recording / reproducing a normal data signal to / from the first concentric area A head having a second function of reading the positioning signal from the second concentric region; and supporting one or more of the heads so as to be displaceable in a radial direction of the magnetic disk. A magnetic disk comprising: a positioning mechanism that controls the positioning of the head with respect to the first concentric area based on the positioning signal obtained from the second concentric area using the function of (2). A magnetic disk in which a processing trajectory in at least one surface processing of the disk material and the magnetic material film intersects the concentric region, wherein the second concentric region and the second concentric region There the magnetic disk device characterized by crossing angle theta ₁ between processing locus in the surface processing for the magnetic disk to be arranged is set to be more than a value represented by the formula (1). 5. An automatic gain control amplifier is connected to the head, and an intersection angle θ of a processing locus in a surface processing with respect to a concentric region of the magnetic disk is represented by the formula (1).
In the value above, and the formula of the magnetic disk surface processing has been performed so that the crossing angle theta ₂ below represented by (2), said first concentric region and a second concentric region identical disc 5. The magnetic disk drive according to claim 4, wherein the magnetic disk drive is used as a magnetic disk disposed on a surface.