JPH10320762A - Plastic magnetic recording medium and recording/ reproducing device for the medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably record and reproduce information by making the thickness of an inner peripheral part thicker than that of an outer peripheral part in a disk shaped plastic magnetic recording medium for recording information, thereby reducing deformation amount at the time of clamping the medium. SOLUTION: The inner peripheral part 3a of a plastic magnetic disk 3 is a part to be clamped by a clamper in order to make a spindle moter rotate the disk 3. The outer peripheral part 3b of the disk 3 is a recording part for recording and reproducing information. Then, the inner peripheral part 3a is made to be a projected shape in the vertical direction of the disk and the thickness A2 of the inner peripheral part 3a is made thicker when it is compared with the thickness A1 of the outer peripheral part 3b. Moreover, since the contact area of the inner peripheral part 3a is wider than that of a disk drive clamper, when the disk is clamped by the clamper, the deformation amount to the outer peripheral part 3b is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic magnetic recording medium for recording information, for example, a replaceable plastic magnetic recording medium of a cartridge type, and a recording / reproducing apparatus for the plastic magnetic recording medium.

[0002]

2. Description of the Related Art As a disk-shaped plastic magnetic recording medium, there is, for example, a magnetic disk. FIG. 8 (A)
FIG. 8B is a plan view and a sectional side view showing an example of a conventional plastic magnetic recording medium. The plastic magnetic magnetic recording medium 103 is, for example, a disk-shaped plastic magnetic disk 103. The plastic magnetic disk 103 has an inner peripheral portion 103a which is an inner peripheral portion of the disk surface and is clamped by a clamper, and an outer peripheral portion 103b which is an outer peripheral portion and is a recording portion for recording and reproducing information. Plastic magnetic disk 1
Reference numeral 03 denotes a magnetic recording medium in which servo pits are preformatted in the information recording area (recording section) or a mirror magnetic recording medium in which the information recording area has no servo pits. The conventional disk-shaped plastic magnetic disk 103 has a thickness A10 of about 1.2 mm from the viewpoint of mechanical characteristics and has a hole near the center. The plastic magnetic disk 103 is shown in FIG.
The thickness A11 of the inner peripheral portion 103a was almost the same as the thickness A10 of the outer peripheral portion 103b as shown in the sectional view of FIG. Steps, burrs, and warpage at the boundary between the clamp area (inner peripheral portion) 103a and the information recording area (outer peripheral portion) 103b may occur on a disk-shaped plastic magnetic disk. Several μm
It is about 数 10 μm, and there is no influence on mechanical characteristics, that is, vibration characteristics and external force applied to the clamp area. that's all,
Although the description has been given of the mirror magnetic recording medium having no servo pits, the pre-formatted magnetic recording medium also has a servo pit of several tens nm in depth.
It is several hundred nm, which is negligible for the amount of deformation due to the mechanical characteristics of the disk-shaped plastic magnetic disk 103.

[0003]

In recent years, there has been an increasing demand for miniaturization and low power of a recording / reproducing apparatus for a plastic magnetic disk. Therefore, a thin disk-shaped plastic magnetic disk having a thickness of 1.2 mm or less has been developed. Use is growing. In particular, there is a strong demand for a recording / reproducing apparatus for a replaceable plastic magnetic disk (removable plastic magnetic disk). However, as shown in FIG. 9, the plastic magnetic disk 1 having a thin disk shape is provided with clampers 115 a and 115 b for clamping the plastic magnetic disk 103.
In the case where 03 is clamped, there is a problem that the outer peripheral portion 103b of the disk-shaped plastic magnetic disk 103 is deformed due to the influence of the tightening at the time of clamping. This deformation appears as a deterioration in runout or a change in the amount of warpage, and has a problem in that it has an adverse effect on the flying characteristics, the Z height, and the like, and affects the recording and reproduction of information.

Accordingly, the present invention solves the above problems, reduces the amount of deformation at the time of clamping, and enables a stable recording and reproduction of information on a plastic magnetic recording medium and a recording and reproducing apparatus for the plastic magnetic recording medium. It is intended to provide.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a disk-shaped plastic magnetic recording medium for recording information, wherein an inner peripheral portion has a thickness greater than an outer peripheral portion. This is achieved by a plastic magnetic recording medium.

In the present invention, the thickness of the inner peripheral portion of the disk-shaped plastic magnetic recording medium is larger than the thickness of the outer peripheral portion. Deformation can be minimized.

[0007]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 is a perspective view showing an embodiment of a recording / reproducing apparatus for a magnetic recording medium made of plastic according to the present invention.
The recording / reproducing device 1 is a disk drive device 1 for recording / reproducing information on / from a plastic magnetic recording medium 3 (plastic magnetic disk) provided in a replaceable cartridge 5.

A disk drive device 1 (recording / reproducing device for a plastic magnetic disk) shown in FIG. 1 is, for example, a rotary actuator 10 having a cartridge 5 detachable from a cartridge mounting portion 12 and a head slider 17 (slider). , A spindle motor 11, a cartridge mounting section 12, a clamper 15, and an arm 19.

[0010] The disk drive device 1 having such a configuration
According to this, when the cartridge 5 is inserted from the direction of the arrow X as shown in FIG. 1, the plastic magnetic disk 3 in the cartridge 5 is clamped by the clamper 15 (clamp portion) integrated with the spindle motor 11, It is rotationally driven by a spindle motor 11. Then, the arm 19 is rotated by the rotary actuator 10, and the head slider 17 provided near the tip of the arm 19 is rotated.
Are arranged on a predetermined track on the plastic magnetic disk 3, and the magnetic head 21 mounted on the head slider 17 records and reproduces information signals on the track.

When the cartridge 5 is to be removed from the disk drive 1, the clamper 15 first moves so as to retreat from the cartridge 5, and the clamped plastic magnetic disk 3 is released. Provided cartridge mounting unit 12
By the operation described above, the cartridge 5 is ejected to the outside.

FIG. 2 is an exploded perspective view showing a detailed example of the cartridge 5. The cartridge 5 shown in FIG. 2 includes a cartridge section 5a, a cartridge section 5b, a cartridge shutter 5c, and a plastic magnetic disk 3.

The plastic magnetic disk 3 has a cartridge section 5a and a cartridge section 5b joined to each other and is incorporated therein. The cartridge unit 5a and the cartridge unit 5b
An access opening 5 which is an opening for exposing a plastic magnetic disk 3 for recording and reproducing information.
d and 5e. Further, one cartridge unit 5
b denotes an opening for the spindle motor 11 for rotating the plastic magnetic disk 3 by clamping and rotating the plastic magnetic disk 3 with the clamper 15 of the spindle motor 11 provided in the disk device 1 of FIG. It has an opening 5f for a certain spindle motor.

The cartridge shutter 5c shown in FIG. 2 is slidably provided so that the access openings 5d and 5e of the cartridge 5 can be opened and closed. The cartridge shutter 5c is slid to a position that covers the access openings 5d and 5e when the cartridge 5 is removed from the disk drive device 1 of FIG. Protect from etc. When the cartridge shutter 5c is mounted on the disk drive device 1 of FIG. 1, the cartridge shutter 5c is slid to a position where the access openings 5d and 5e are opened so that information can be recorded and reproduced.

Embodiment 1 FIGS. 3A and 3B are a plan view and a sectional side view showing an embodiment of a plastic magnetic recording medium according to the present invention. The plastic magnetic recording medium 3 in FIG. 3A is, for example, a disk-shaped (disk-shaped) plastic magnetic disk.

Inner peripheral portion 3 of plastic magnetic disk 3
Reference numeral a denotes a portion for clamping the plastic magnetic disk 3 by the clamper 15 (clamp portion) shown in FIG. The outer peripheral portion 3b of the plastic magnetic disk 3 is a recording unit for recording and reproducing information by the magnetic head 21 of FIG. As shown in FIG. 3B, the inner peripheral portion 3a has a convex shape in the direction perpendicular to the disk surface, and has a thickness A2 of the inner peripheral portion 3a.
Is thicker than the thickness A1 of the outer peripheral portion 3b. Each of the protrusions provided on the disk surfaces on both sides of the plastic magnetic disk 3 in FIG. 3 may have the same shape or different shapes.

Embodiment 2 FIGS. 4A and 4B are a plan view and a sectional side view showing another embodiment of the plastic magnetic recording medium of the present invention. Plastic magnetic recording medium 3 of FIG.
Has almost the same configuration as the plastic magnetic disk 3 of FIG. The difference is that a protrusion of the inner peripheral portion 3a of the plastic magnetic disk 3 is provided on one disk surface.

Next, the situation where the plastic magnetic disk 3 of the first embodiment is clamped by the clamper 15 (clamp portion) is simulated, and the calculated value of the deformation T of the outer peripheral portion 3b of the plastic magnetic disk 3 is calculated. Ask. Note that a model that clamps from both sides of the disk surface is used for the clamp unit 15 in order to clarify the deformation amount T.

FIG. 5 is a sectional side view of a half of the center of the plastic magnetic disk 3 when the plastic magnetic disk 3 of FIG. 3 is clamped and viewed from the disk surface horizontal direction. 2 shows a state where the clamper 15 is clamped by clampers 15a and 15b constituting the clamp unit 15. In FIG. 5, only half of the plastic magnetic disk 3 and the clampers 15a and 15b are shown, but the omitted parts have substantially the same structure. As shown in FIG. 5, when the clampers 15 a and 15 b of the clamp portion of the disk drive 1 clamp the inner peripheral portion 3 a of the plastic magnetic disk 3, the clamping force applies an evenly distributed load to the plastic magnetic disk 3. Is shown. The clampers 15a and 15b operate in the Y direction, contact the inner peripheral portions 3a and 3a of the disk surfaces on both sides of the plastic magnetic disk 3, and clamp them.

The plastic magnetic disk 3 to be simulated has an inner peripheral portion 3a as shown in FIG.
Prepares a plastic magnetic disk 103 which is flatter than the outer peripheral portion 3b, and a plastic magnetic disk 3 whose inner peripheral portion 3a has a thickness A2 which is thicker than the outer peripheral portion 3b as shown in FIG. And make a comparison.

Here, the plastic magnetic disk 3
In the case where a 2.5-inch-diameter disk-shaped plastic magnetic disk having a thickness A1 of the outer peripheral portion 3b of 0.5 mm is used, a positional shift W1 of the center of the upper and lower clampers 15a and 15b in the disk surface direction is obtained. The amount of deformation T of the outer peripheral portion 3b when clamping in the state of 0.1 mm is calculated by simulation.

The plastic magnetic disk 3 has a radius R3 = 10 mm from the center to the radius R
The thickness A2 up to 4 = 12 mm was 1 mm. The range clamped by the clampers 15a and 15b is a radius R2 = 1 from the center of the disk-shaped plastic magnetic disk 3.
It is a portion with a radius R1 = 11.5 mm from 0.5 mm.
The calculated value is torque 0.4kg ・ f ・ c by M2 screw.
It is assumed that the clamp is performed by tightening with m.

As a result, the inner peripheral portion 3 as shown in FIG.
FIG. 5 shows a plastic magnetic disk 103 having a flat a.
The simulation calculation value of the deformation amount (deflection) T of 4.
In contrast to 3 μm, when the thickness A2 of the inner peripheral portion 3a of the plastic magnetic disk 3 in FIG. 3 is larger than the thickness A1 of the outer peripheral portion 3b, it is as small as 3.1 μm. Since the deformation is proportional to the load, if the tightening force increases, the effect of further increasing the thickness of the inner peripheral portion 3a increases. It has been confirmed that the simulation matches well with the actual measurement.

FIG. 6 is a sectional side view of a half of the center of the plastic magnetic disk 3 when the plastic magnetic disk 3 of FIG. 3 is clamped and viewed from the disk surface horizontal direction. As shown in FIG. 6, when the clampers 15 a and 15 b of the clamp portion of the disk drive 1 clamp the inner peripheral portion 3 a of the plastic magnetic disk 3, the clamping force applies an evenly distributed load to the plastic magnetic disk 3. Is not the case. In reality, the possibility of clamping under such extremely poor conditions is small, but the inner peripheral portion 3a of the plastic magnetic disk 3 is
This is an appropriate simulation calculation model for estimating the deformation amount T when the clamp A is performed in a state where the thickness A2 is larger than the thickness A1 of the outer peripheral portion 3b. The sample of the plastic magnetic disk 3 is the same as above.

The clamping range is such that a portion having a radius of 10.5 mm to 11.5 mm from the center of the disk-shaped plastic magnetic disk 3 is clamped by the clampers 15 a and 15 b of the disk drive 1. This calculated value is M2
It is assumed that the screws are tightened and clamped with a torque of 0.4 kg · f · cm. The clamper 15 of FIG.
Because the contact surface of b is not flat, for example, from the center of the plastic magnetic disk 3 to the radius R2 = 10.5 mm to the outer periphery, only the width W2 = 0.25 mm,
It is assumed that they are clamped by the clampers 15a and 15b.

As a result, the inner peripheral portion 3 as shown in FIG.
6A is 75.4 μm, whereas the plastic magnetic disk 103 whose “a” is flatter than the outer peripheral portion 3b has a calculated value of the variation (deflection) T of FIG. 6 of 75.4 μm.
In the case where the thickness A2 of the inner peripheral portion 3a of the plastic magnetic disk 3 of (B) is larger than the thickness A1 of the outer peripheral portion 3b, 4
It is as small as 7.7 μm. From this, it can be seen that the effect is obtained by making the thickness A2 of the inner peripheral portion 3a of the plastic magnetic disk 3 larger than the thickness A1 of the outer peripheral portion 3b.

FIG. 7 is a half sectional side view from the center of the plastic magnetic disk when the plastic magnetic disk 3 of FIG. 3 is clamped and viewed from the disk surface horizontal direction. As shown in FIG.
When the clampers 15a and 15b of the clamp section 15 clamp the inner peripheral portion 3a of the plastic magnetic disk 3, the clamping force is an evenly distributed load on the plastic magnetic disk 3. The shape of the plastic magnetic disk 3 and the clamping force when the clamper clamps are the same as those in the two simulations described above.

The shape of the clampers 15a and 15b is such that the area of the contact surface 22 of the clampers 15a and 15b of the disk drive 1 is reduced as shown in FIG.
Has a structure wider than the area of the contact surface 23 of the inner peripheral portion 3a. Center displacement W1 = 0 of clampers 15a, 15b
mm, and the plastic magnetic disk 3 is clamped in the same state. The calculated value of the simulation of the deformation amount T of the plastic magnetic disk 3 having this structure is 0 μm. With this structure, the amount of deformation T when the plastic magnetic disk 3 is clamped can be greatly reduced. By using such a clamp portion 15 and the plastic magnetic disk 3, deformation of the plastic magnetic disk 3 during clamping can be suppressed. The use of such a clamp 15 and the plastic magnetic disk 3 for the disk drive device 1 is particularly effective when a thin plastic magnetic disk 3 is used.

By adopting the above-described configuration of the plastic magnetic disk 3 in the disk drive device 1, when the plastic magnetic disk 3 is clamped, the amount of deformation T of the plastic magnetic disk 3 with respect to the outer peripheral portion 3b is minimized. can do. Increasing the thickness A2 of the inner peripheral portion 3a of the plastic magnetic disk 3 in FIG. 3B does not increase the size of the disk drive device 1 of the plastic magnetic disk 3. For example, in the case of a recording / reproducing apparatus of a type using a plurality of disk-shaped plastic magnetic disks, the plastic magnetic disks are usually used in a stacked state. Increasing the thickness of the plastic magnetic disk is likely to increase the size of the recording / reproducing device.However, between each plastic magnetic disk, there is a space for the slider on which the head that records information on the plastic magnetic disk is located. Required. Therefore, it is possible to secure a space between the plastic magnetic disks as an area where the slider or the like operates.

Even in a recording / reproducing apparatus using only one plastic magnetic disk, an area in which a slider and the like are arranged is the same as in the case where a plurality of plastic magnetic disks are provided. 2 to secure Z height
A fixed interval is required between the attachment portions of the two arms. The necessary interval is the thickness of the plastic magnetic disk + Z height × 2. Usually, the portion of the recording / reproducing apparatus for a plastic magnetic disk which requires the largest thickness is a voice coil motor (VCM) for controlling the position of the head.
r) part or bearing bearing part. These can all be made thinner as the distance between the arms becomes narrower.

A replaceable plastic magnetic disk,
For example, in the case of a removable magnetic disk, the thickness of the shell (cartridge) depends on the opening into which the head enters. The required dimensions of the opening can be reduced by increasing the ramp pressure for guiding the head arm, the clearance between the medium and the ramp, and increasing the thickness of the data area of the medium.

Although the plastic magnetic disk 3 and the recording / reproducing apparatus 1 (disk drive) for the plastic magnetic disk 3 according to the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. The clamp 15 and the plastic magnetic disk 3 can be used for a magnetic disk device (hard disk device or the like) from which the plastic magnetic disk 3 cannot be taken out.

[0033]

As described above, according to the present invention,
Since the thickness of the inner peripheral portion of the disk-shaped plastic magnetic disk is thicker than the outer peripheral portion, when the plastic magnetic disk is clamped, the amount of deformation to the outer peripheral portion is minimized. be able to. Also, the area of the contact surface of the inner peripheral portion of the disk-shaped plastic magnetic disk is larger than the area of the contact surface of the clamper of the disk drive. The amount can be minimized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a recording / reproducing apparatus for a plastic magnetic recording medium according to the present invention.

FIG. 2 is an exploded perspective view showing an example of a cartridge having one embodiment of a plastic magnetic recording medium according to the present invention.

FIG. 3 is a plan view and a cross-sectional side view showing one embodiment of a plastic magnetic recording medium according to the present invention.

FIG. 4 is a plan view and a sectional side view showing another embodiment of the plastic magnetic recording medium according to the present invention.

FIG. 5 is a first sectional view showing a state when the plastic magnetic recording medium of FIG. 3 is clamped.

FIG. 6 is a second sectional view showing a state when the plastic magnetic recording medium of FIG. 3 is clamped.

FIG. 7 is a third sectional view showing a state when the plastic magnetic recording medium of FIG. 3 is clamped.

FIG. 8 is a plan view and a sectional side view showing an example of a conventional plastic magnetic recording medium.

FIG. 9 is a cross-sectional side view showing a state of a plastic magnetic recording medium when a conventional plastic magnetic recording medium is clamped.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disk drive apparatus (recording / reproducing apparatus of a plastic magnetic recording medium) 3 ... Plastic magnetic disk (plastic magnetic recording medium), 3a ...
Inner peripheral part, 3b ... outer peripheral part, 15 ... clamp part (clamper), 15a ... clamper, 15b ... clamper

Claims (10)

[Claims] 1. A disk-shaped plastic magnetic recording medium for recording information, wherein the thickness of an inner peripheral portion is larger than the thickness of an outer peripheral portion. 2. The plastic magnetic recording medium according to claim 1, wherein a convex portion is provided on at least one surface of the inner peripheral portion. 3. The plastic magnetic recording medium according to claim 1, wherein the inner peripheral portion is a clamp that contacts a clamper that clamps the plastic magnetic recording medium. 4. The plastic magnetic recording medium according to claim 3, wherein the area of the contact surface of the clamper is larger than the area of the contact surface of the inner peripheral portion. 5. The plastic magnetic recording medium according to claim 1, wherein the outer peripheral portion is a recording portion for recording information. 6. The plastic magnetic recording medium according to claim 1, wherein the plastic magnetic recording medium is a replaceable magnetic disk. 7. A disk-shaped plastic magnetic recording medium having an inner peripheral part having a thickness greater than that of an outer peripheral part, and recording / reproducing means for recording / reproducing information on / from the plastic magnetic recording medium. A recording / reproducing apparatus for a plastic magnetic recording medium, comprising: 8. The recording / reproducing apparatus for a plastic magnetic recording medium according to claim 7, wherein a projection is provided on at least one surface of an inner peripheral portion of the plastic magnetic recording medium. 9. A method according to claim 1, further comprising a clamper for contacting an inner peripheral portion of the plastic magnetic recording medium to clamp the plastic magnetic recording medium, wherein a contact surface area of the clamper is larger than an area of the inner peripheral contact surface. Item 8. A recording / reproducing apparatus for a plastic magnetic recording medium according to Item 7. 10. The recording / reproducing apparatus for a plastic magnetic recording medium according to claim 7, wherein the plastic magnetic recording medium is a replaceable magnetic disk.