JPH06314457A - Discoid recording medium - Google Patents

Abstract

PURPOSE:To diminish an eccentric amt. when a hub is fitted into a center hole of a recording medium main body part of the discoid recording medium such as an MO disk, etc. CONSTITUTION:The discoid recording medium 1 is composed of the recording medium main body part 2 and the hub 4 fitted into the center hole 3 of the recording medium main body part 2. The hub 4 is provided with a 1st centering hole 5 to be used at the time of chucking the hub 4 to a turntable of a drive and a 2nd centering hole 6 to be used at the time of fitting the hub 4 to the recording medium main body part 2. The hub 4 is composed of 1st and 2nd hub constituting bodies 11 and 12. The 1st hub constituting body 11 is provided with the 1st centering hole 5. The 2nd hub constituting body 12 is provided with the 2nd centering hole 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed to mount a hub in the center and insert the upper end of a spindle shaft into a centering hole (hub hole) provided in the hub for centering on a turntable. In particular, the present invention relates to a disc-shaped recording medium which can reduce the amount of eccentricity of the centering hole when the hub is assembled (attached) to the recording medium body.

[0002]

2. Description of the Related Art As a disk-shaped recording medium, an optical recording medium for reproduction (reading) only (hereinafter referred to as CD-ROM)
There is known an optical recording medium or a magneto-optical recording medium (hereinafter referred to as an MO disk) that can be rewritten by optical modulation or magnetic field modulation.

The MO disk is used not only for reproduction or for audio recording, but also for data recording for recording data processed by a computer like an external storage device of a computer.

FIG. 8 shows an MO disc 101 for reproduction only.
And a rotation drive mechanism 1 of a disk drive for reproducing the same.
02 is shown.

A center hole 103 is provided at the center of the reproduction-only MO disk 101.

The rotary drive mechanism 102 includes a spindle motor 104 and a turntable 1 attached to a shaft (hereinafter referred to as a spindle shaft) 105 of the spindle motor 104.
06, and a chucking plate 107 made of a magnet for chucking the disk 101 placed on the turntable 106.

On the outer circumference of the turntable 106,
A ring-shaped disk mounting reference surface 108 is provided, and a truncated cone-shaped convex portion 1 for centering is provided in the center portion.
09 are provided.

Then, as shown in FIG. 9, the read-only MO disk 101 centered on the inclined surface of the outer periphery of the centering convex portion 109 is a chucking plate 107, and a disk supporting reference surface of the turntable 106. It is pressed against 108 and is in a so-called chucked state, and is rotated together with the turntable 106 by the spindle motor 104.

FIG. 10 shows an MO disk 1 for recording data.
11 and a rotation drive mechanism 112 of the disk drive for reproducing the same.

The MO disk 111 for recording the above data
Due to the nature of recording data, a more accurate centering is required as compared with the read-only MO disc 101.

Therefore, the MO disk 11 for data recording
1 is configured by mounting a metal hub 113 for high-accuracy center positioning in a center hole 103 of a reproduction-only MO disc (hereinafter, referred to as a recording medium main body) 101.

At the center of the hub 113, a centering hole 114 is provided for inserting the upper end of the spindle shaft of the rotary drive mechanism 112, which will be described next.

The rotary drive mechanism 112 includes a spindle motor 115 and a shaft of the spindle motor 115 (hereinafter,
Spindle shaft) 116, and the spindle shaft 116
Turntable 117 mounted on the table, and chucking magnet 1 provided on the turntable 117
18 and 18.

Then, as shown in FIG. 11, when the data recording MO disk 111 is attracted to the turntable 117 side by the chucking magnet 118, the tip of the spindle shaft 116 is centered on the hub 113. The centering hole 114 provided in the section is inserted to center the MO disk 111 for data recording.

Reference numeral 119 is a disk support reference surface provided on the turntable 117.

[0016]

In the conventional MO disk for recording data, the centering hole 114 is formed by inserting the tip of the spindle shaft 116 into the centering hole 114 of the hub 113. The inner diameter of the shaft 116 corresponds to the outer diameter of the tip of the shaft 116.

In particular, the turntable 117 and the hub 113
The tip of the spindle shaft 116 is moved to the centering hole 114 by the attractive force of the chucking magnet 118 provided on the
In the case of inserting into the centering hole 114, the force of making the tip of the spindle shaft 116 enter the centering hole 114 is weaker than in the case where the tip of the spindle shaft 116 is forcibly inserted into the centering hole 114 using a mechanical mechanism.

For this reason, the chucking magnet 1 is used.
When the tip of the spindle shaft 116 is inserted into the centering hole 114 by the suction force of 18, the inner diameter of the centering hole 114 is larger than when the tip of the spindle shaft 116 is inserted into the centering hole 114 by using a mechanical mechanism. Is set to have a slightly larger diameter, and when the tip of the spindle shaft 116 is inserted into the centering hole 114, the sliding friction generated between them is minimized so that the spindle shaft 116 can be smoothly inserted into the centering hole 114. Has become. (When the spindle shaft 116 is inserted into the centering hole 114 by using a mechanical mechanism, the spindle shaft 116 can be forcibly inserted even if the sliding friction between them is somewhat large. Therefore, the inner diameter of the centering hole 114 can be made smaller. Therefore, the clearance between the centering hole 114 and the spindle shaft 116 can be reduced).

However, as described above, if the inner diameter of the centering hole 114 is increased in order to facilitate the insertion of the spindle shaft 116 into the centering hole 114, the hub 113 will not be attached to the center hole 103 of the recording medium body 101. In addition, the eccentric amount between the center of the centering hole 114 and the center of the information (group) recorded in the recording medium body 101 may be increased.

Because, when the hub 113 is assembled to the recording medium main body 101, as shown in FIG. 11, it is used as a hub positioning shaft of the hub assembling device 121 having the same diameter as the spindle shaft. Jig for inserting centering hole
2 into the centering hole 114 of the hub 113,
After aligning the center of the hub 113 with the center of the information of the recording medium body 101, the hub 113 is moved to the recording medium body 1
No. 01 is attached to the centering hole 114 by an adhesive agent 120 or the like. However, as described above, when the inner diameter of the centering hole 114 is increased, when the jig 122 is inserted into the centering hole 114, the play between them occurs. This is because the (clearance) also becomes large, and the hub 113 may be eccentric, and the hub 113 may be assembled in the recording medium body 101.

According to the present invention, a centering hole for inserting a jig for inserting a centering hole of a hub assembling apparatus used when assembling a hub to a recording medium body and a disc-shaped recording medium are mounted on a turntable. By forming the centering hole in the original meaning used for the above in the hub separately and using these centering holes properly, the above-mentioned conventional problems can be solved.

[0022]

According to a first aspect of the present invention, there is provided a disk-shaped recording medium having a recording medium main body and a hub attached to a center hole of the recording medium main body. A first centering hole used when chucking the turntable and a second centering hole used when assembling the hub to the recording medium body are provided.

According to a second aspect of the present invention, in the disk-shaped recording medium according to the first aspect, the hub has a first hub structure having a first centering hole and a second hub structure having a second centering hole. The first and second hub components are provided with a fitting portion and a fitted portion, and the fitting portion and the fitted portion are fitted to each other by dividing the body into With the centers of the second centering holes aligned, the first and second
The hub structure of the above can be integrally connected.

The invention of claim 3 is the same as claim 1 or claim 2.
In the disk-shaped recording medium (1), the first centering hole was provided in the lower hub structure and the second centering hole was provided in the upper hub structure.

The invention of claim 4 is the same as claim 1 or claim 2.
Alternatively, in the disk-shaped recording medium according to claim 3, the second centering hole is constituted by a reference surface for positioning the jig of the hub assembling device and a spring member for pressing the jig on the reference surface.

According to a fifth aspect of the present invention, in the disk-shaped recording medium according to the fourth aspect, the reference surface and the spring material are brought into contact with three positions on the outer peripheral surface of the jig of the hub assembling device at substantially equal intervals.
They were arranged in a substantially triangular shape on a plane.

[0027]

In the disk-shaped recording medium according to claim 1, a second centering hole is used when the hub is attached to the main body of the recording medium, and the hub assembling device is fixed to the second centering hole. The hub can be assembled to the recording medium body by inserting a tool and aligning the center of the hub with the center of information in the recording medium body.

In the disk-shaped recording medium according to the second aspect, if the fitting portion and the fitted portion of the first hub component and the second hub component are fitted, The two hub components are integrally connected, and the first and second centering holes provided in the first and second hub components are aligned with each other.

In the disk-shaped recording medium according to the third aspect, the tip of the spindle shaft of the turntable penetrates only into the first centering hole provided in the lower hub structure when chucking the turntable. The disk-shaped recording medium is centered.

In the disk-shaped recording medium according to claim 4, when the jig of the hub assembling device is inserted into the second centering hole when the hub is attached to the recording medium main body, the jig is
It is pressed against the reference surface with a spring material and fixed in place.

In the disk-shaped recording medium according to the fifth aspect, the jig of the hub assembling device is attached at three substantially equal intervals on the outer peripheral surface by the reference surface and the spring material arranged in a plane triangular shape. Is supported by the central portion of the reference surface and the spring member.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to FIGS. FIG. 1 shows a disk-shaped recording medium of the present invention (rewritable M
It is sectional drawing of (O disk).

The disc-shaped recording medium 1 has a recording medium body 2 and a hub 4 attached to a center hole 3 of the recording medium body 2.

The recording medium body 2 is made of plastic.

The hub 4 is made of a metal plate.

At the bottom of the hub 4, there is a first centering hole 5 used for chucking the turntable.
Is provided.

On the upper part of the hub 4, a second centering used when the hub 4 is assembled (attached) to the recording medium body 2 while being continuous with the first centering hole 5. A hole 6 is provided.

The first centering hole 5 is formed with an inner diameter φA into which the tip of the spindle shaft can be smoothly inserted.

A jig for inserting the centering hole of the hub assembling device (the jig has the same diameter as the spindle shaft and is formed longer than this) is inserted into the second centering hole 6 without rattling. Therefore, the inner diameter φB is smaller than the inner diameter of the first centering hole 5.

The hub 4 has a first hub, as shown in FIG.
The hub structure 11 and the second hub structure 12 are included.

The first hub assembly 11 comprises a plastic base plate 13 and a cylindrical fitting portion 14 integrally formed with the base plate 13 at the center of the upper surface of the base plate 13. A metal plate 15 having a magnet attracting property is inserted in the base plate 13.

The first centering hole 5 is provided at the center of the base plate 13.

The fitted portion 14 is formed in a cylindrical shape having an inner diameter φC, an outer diameter φD, and a height H, with the center (hole core) aligned with the first centering hole 5.

The second hub assembly 12 is composed of a plastic base plate 16 and a cylindrical fitting portion 17 integrally formed with the base plate 16 at the center of the lower surface thereof.

The base plate 16 and the fitting portion 17
A second centering hole 6 is formed in the central portion of the so as to penetrate the both.

The outer diameter φE of the fitting portion 17 is formed to be slightly larger than the inner diameter φC of the fitted portion 14.

Then, the fitting portion 17 is connected to the fitted portion 1
By press-fitting into the first and second hub components 1
The first and the second centering holes 12 are joined together so that the centers of the first and the second centering holes 5 and 6 are aligned.

The second centering hole 6 is, as shown in FIG. 3, the first and second reference planes for positioning the jig 32 for inserting the centering hole of the hub assembling apparatus 31 described below. 21, 22 and these first and second reference planes 21,
In order to press the outer peripheral surface of the jig 32 against the 22, a spring member 23 integrally formed with the second hub structure 12 is used.

The first and second reference surfaces 21 and 22 and the spring member 23 are arranged in a substantially triangular shape in a plane, and the first and second reference surfaces 21 and 22 and the spring member 23 serve to cure the above. The outer peripheral surface of the tool 32 is held at three positions at equal intervals.

Next, assembling of the hub 4 into the center hole 3 of the recording medium body 2 in the disc-shaped recording medium 1 will be described.

As shown in FIG. 4, first, the fitted portion 14 of the first hub assembly 11 is inserted into the center hole 3 from the lower surface side of the recording medium body portion 2.

Next, the fitting portion 17 of the second hub assembly 12
From the upper surface side of the recording medium body 2 to the fitted portion 14
The hub 4 is loosely fitted into the center hole 3 by press-fitting it therein.

After that, the jig 32 of the hub assembling device 31
Is inserted into the second centering hole 6 so that the center of the information (group) of the recording medium body 2 and the center of the second centering hole 6 coincide with each other, the center of the information (group) The center of the first centering hole 5 is naturally aligned.

As described above, the center of the information (group) and the centers of the first and second centering holes 5 and 6 are aligned with each other, and then the hub 4 is attached to the recording medium body 2 by using an adhesive or the like. It should be fixedly assembled.

FIG. 5 shows a state in which the disc-shaped recording medium 1 of the present invention is chucked on the turntable 41 of the drive, and the tip of the spindle shaft 42 penetrates only into the first centering hole 5 to form a disc. The recording medium 1 is centered.

6 to 7 show modified examples of the reference surface and the spring member for holding and supporting the hub positioning jig 32.

FIG. 6 shows a case where a leaf spring is used as the spring member 23.

FIG. 7 shows a case where the spring member 23 itself constitutes the reference surface.

[0059]

The disk-shaped recording medium of the present invention has the following effects.

In the disk-shaped recording medium according to claim 1, the first and second centering holes provided in the hub are selectively used, and the first centering hole is used exclusively for chucking the turntable of the drive. However, since the second centering hole is exclusively used only when the hub is assembled to the main body of the recording medium, the inner diameter of the second centering hole is reduced as much as possible, and the backlash with the jig of the hub mounting device ( By reducing the clearance, it is possible to reduce the amount of eccentricity between the center of the first centering hole and the center of the information provided in the recording medium body when the hub is assembled to the recording medium body.

In the disk-shaped recording medium according to the second aspect of the present invention, by fitting the fitting portion and the fitted portion to each other, the first and second hub components are integrally coupled to form a hub. can do. Then, if the first and second hub structures are integrally connected, the centers of the first and second centering holes are naturally aligned, and they are continuous in the vertical direction.

In the disk-shaped recording medium of the third aspect, the first centering hole is provided below and the second centering hole is provided above the first centering hole. By adjusting the height of the first centering hole, interference between the spindle shaft and the second centering hole can be prevented.

In the disk-shaped recording medium according to the fourth aspect, the jig of the hub assembling device is sandwiched between the reference surface and the spring material,
Firmly supported within the second centering hole.

In the disk-shaped recording medium according to the fifth aspect, the jig of the hub assembling apparatus can hold the reference surface and the spring member at three positions on the outer peripheral surface at substantially equal intervals, and Supported.

[Brief description of drawings]

FIG. 1 is a sectional view of a disk-shaped recording medium.

FIG. 2 is a sectional view of the hub.

FIG. 3 is a cross-sectional view of a second hub structure.

FIG. 4 is a cross-sectional view showing an assembled state of the hub to the recording medium body.

FIG. 5 is a cross-sectional view showing a chucking state of a drive on a turntable.

FIG. 6 is a cross-sectional view of a modified example of the second hub structure.

FIG. 7 is a cross-sectional view of a modified example of the second hub structure.

FIG. 8 is a perspective view of a reproduction-only MO disc and a rotation drive mechanism.

FIG. 9 is a sectional view of a usage state.

FIG. 10 is a perspective view of an MO disk for recording data and a rotation drive mechanism.

FIG. 11 is a cross-sectional view of a usage state.

FIG. 12 is a sectional view showing an assembled state of the hub.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disc-shaped recording medium 2 ... Recording medium main body 3 ... Center hole 4 ... Hub 5 ... 1st centering hole 6 ... 2nd centering hole 11 ... 1st hub structure 12 ... 2nd hub structure 14 ... Fitted part 17 ... Fitting parts 21, 22 ... Reference surface 23 ... Spring material 31 ... Hub assembly device 32 ... Centering hole insertion jig (shaft)

Claims (5)

[Claims] 1. A recording medium body, and a hub attached to a center hole of the recording medium body, wherein the hub has a first centering hole used when chucking a drive turntable. A disk-shaped recording medium having a second centering hole used when the hub is assembled to the recording medium main body. 2. The disc-shaped recording medium according to claim 1, wherein the hub is divided into a first hub structure having a first centering hole and a second hub structure having a second centering hole. In addition, the first and second hub components have a fitting portion and a fitted portion, and by fitting the fitting portion and the fitted portion, the first and second The disc-shaped recording medium, wherein the first and second hub components are integrally coupled with each other with their centering holes aligned. 3. The disk-shaped recording medium according to claim 1 or 2, wherein the first centering hole is provided in the lower hub structure.
The disk-shaped recording medium in which the second centering hole is provided in the upper hub structure. 4. The disk-shaped recording medium according to claim 1, 2 or 3, wherein the second centering hole is a reference surface for positioning a jig for inserting the centering hole of the hub assembling device. A disc-shaped recording medium comprising a spring member for pressing the jig on the reference surface. 5. The disk-shaped recording medium according to claim 4, wherein the reference surface and the spring member are in contact with the outer peripheral surface of the jig for inserting the centering hole of the hub assembling apparatus at three positions at substantially equal intervals. A disk-shaped recording medium arranged in a substantially triangular plane.