JPH0778906B2 - Information storage medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is for driving an information storage medium such as an optical disc and recording, reproducing, or erasing information by using a laser beam or the like during its rotation. The present invention relates to improvement of an information storage medium used in an information processing device that performs information processing.

[Conventional technology]

In recent years, an information processing device using an optical disk as a storage medium can significantly increase the information storage capacity as compared with a magnetic information processing device which has been widely used in the past, and has extremely low noise and excellent and stable information. The playback state is obtained, the storage state is not easily affected by external influences, and the storage state is extremely stable. Moreover, information processing can be performed in a non-contact state, and there is no adverse effect such as damage to the storage medium and the information processing head. It is being used a lot because it has.

In addition, along with this trend of increasing usage, it has recently been demanded to make the information processing apparatus of this kind, for example, an information recording / reproducing apparatus, as thin as possible, light in weight, and low in cost.

On the other hand, in the conventional device, as shown in FIGS. 6 and 7, the information storage medium (optical disk) a is replaced with the turntable b.
In the case of fixing the information storage medium (optical disk) a to the turntable b side via the clamper c, the information storage medium (optical disk) a is pressed.

6 shows a structure in which a pressing force is applied to a clamper c through a supporting means e provided with an urging body d such as a spring, and a structure shown in FIG. 7 is a magnet f to the clamper c. And a pressing force is applied to the clamper c by a magnetic attraction force generated between the clamper c and the turntable b made of a magnetic material.

[Problems to be solved by the invention]

However, in such a conventional device, not only the clamper c is required, but also a moving space necessary for moving the clamper c must be formed, and the clamper c is contacted and separated. A mechanism etc. is required. For this reason, the structure of this portion becomes complicated and large, which is not only a major obstacle to thinning, weight reduction and cost reduction, but also there is a problem that assembly and maintenance are troublesome.

Further, in the former type (FIG. 6), since the turntable a is always in a state of receiving a force, the turntable b and the rotary shaft g integral with the turntable b must be made solid.
Further, in the latter (FIG. 7), the holding force varies depending on the thickness of the information storage medium a, and when the information storage medium a is a comparatively thick one such that two substrates h are stuck together, it is sure to occur. There is a problem that it may not be able to be pinched.

Further, conventionally, the inner diameter portion i of the information storage medium a, that is, the inner diameter portion of the synthetic resin substrate h is directly fitted to the positioning portion j formed on the turntable b side to perform positioning. Therefore, the diameter of the inner diameter portion i of the information storage medium a may change due to wear for a long time, and the center and the rotation center of a pregroup (not shown) spirally formed on the substrate h at a pitch of 1.6 μm. However, there is a serious problem that the eccentricity becomes large and the recording / reproducing of information is adversely affected.

The present invention has been made in view of the above circumstances, and an object thereof is to use an information storage medium without using a clamper which is an obstacle to thinning, weight reduction, cost reduction, and the like. It can be mounted easily and securely regardless of the thickness,
Moreover, the present invention aims to provide an information storage medium that is free from eccentricity and is capable of stable information processing.

(Means for Solving Problems) In order to solve the above problems, the present invention provides an information storage medium which is mounted on a turntable containing a magnetic circuit forming member for forming a magnetic circuit in a recess and is rotationally driven. , A substrate having a hole in the center of rotation and facing each other and having a recording layer on the facing surface, and a convex portion having a dimension set smaller than the thickness of the substrate, the convex portion of the substrate A member to be attracted, which is attached to the non-opposing surface of the substrate by being fitted in the opening and is magnetically attracted to the turntable side, is provided.

[Action]

That is, according to the present invention, since the information storage medium can be magnetically attached to the turntable by the above-mentioned configuration, it is possible to reduce the thickness, weight, cost, etc. of the device conventionally required. It is possible to eliminate the obstruction of the clamper. Further, the dimension of the convex portion of the member to be attracted is set to be smaller than the thickness of the substrate of the information storage medium so that it can be fitted only to a good portion, not a poor finished state caused by the molding conditions of the substrate. By
A highly accurate eccentricity can be easily obtained, and stable information processing can be performed.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows the state in which the book is worn, and FIG. 2 shows the state in which the book is not attached. In FIG. 1, reference numeral 1 denotes an information storage medium (hereinafter referred to as a disc) housed in a cartridge 2, and the disc 1 is inserted together with the cartridge 2 into a medium insertion / ejection opening formed in a main body (not shown) of an information processing apparatus. It has become so.

The disc 1 inserted together with the cartridge 2 is automatically taken into a predetermined position and in a horizontal state by a medium taking-in / mounting mechanism (not shown), and at this time, the cartridge 2 exposes a part of the disc 1. The center of rotation is open. After that, the cartridge 2 is displaced in the surface direction, and the disc 1 is automatically mounted on the turntable 4 of the medium driving means 3.

The disc 1 comprises two substrates 6 each having an information recording layer 5,
6 is adhered with an inner spacer 7 and an outer spacer (not shown) sandwiched so that the information recording layers 5 and 5 are on the inner side, and magnetically attracted to both sides of the inner diameter portion (magnetic material). ) As a metal member (hereinafter referred to as a hub) 8,8 is attached.

The substrates 6 and 6 are made of injection-molded transparent synthetic resin plates and are bonded to the inner spacer 7 and the outer spacer via an ultraviolet curing adhesive.

The hub 8 has a shape having a central hole 10 that fits with the centering portion 9a of the rotary shaft 9 of the medium driving means 3.
The substrates 6 and 6 are bonded to each other with an adhesive that does not adversely affect the substrates 6 and 6, for example, an epoxy adhesive.

Further, as shown in detail in FIG. 1, the hub 8 is formed with a convex portion 8a. The outer diameter portion of the hub 8 is fitted to the inner diameter portion 6a of the substrate 6 so as to be positioned with respect to the substrate 6. There is.

FIG. 4 shows a state during molding of the substrate 6, in which the inner diameter portion 6a which is a central hole is simultaneously opened in order to shorten the processing time.

In the figure, A is a fixed type, B is a movable type, and C is a fixed type A. A sprue bush (die) guided by a bush guide D.
And E is a punch guided by the punch guide F.

Then, in the illustrated state, the molten synthetic resin material a has a sprue bush (die) C as indicated by an arrow a.
After pouring into the cavity H formed in the mutually facing surface portion of the fixed die A and the movable die B through the sprue G formed in the, the punch E moves in the arrow B direction to form the inner diameter portion 6a. Become.

At this time, as shown in FIG.
6b occurs. This occurs because the resin of the gate part is cut off by the punch E,
The step portion 6b is projected on the surface opposite to the outer surface of the substrate so that the inner diameter becomes small.

The stepped portion 6b has a slight step, but the surface is not smooth and the accuracy is poor.

As described above, since the inner diameter of the substrate 6 is more accurate on the outer surface side of the substrate 6, the dimension h ₁ of the convex portion 8a of the hub 8 is set to be smaller than the thickness h ₂ of the substrate 6 to improve the accuracy. The convex portion 8a of the hub 8 is fitted only to a portion having a good eccentricity so that good positional accuracy with little eccentricity is maintained.

The inner diameter portion 6a of the substrate 6 is precisely formed coaxially with the recording / reproducing pregroup (not shown) formed on the substrate 6, and the outer diameter portion of the convex portion 8a of the hub 8 and the hub 8 are formed. The center hole 10 is precisely processed coaxially, so that the center of the pregroup and the rotation axis of the rotation shaft 9 can be aligned with each other. Further, it is possible to prevent problems such as a decrease in recording / reproducing accuracy and an increase in access time caused by the eccentricity.

The medium driving means 3 is an outer rotor type brushless DC motor having a motor shaft as the rotating shaft 9.
11 and a turntable 4 attached to a rotary shaft 9 of the motor 11.

The turntable 4 is made of a non-magnetic metal material, and a recess 4a is formed on the upper surface side thereof. A magnetic circuit forming member 14 including a magnet 12 for magnetically attracting the center hub 8 of the information storage medium 1 and a yoke 13 is housed in the recess 4a. This is to fully exert the force for mounting the disk 1 on the turntable 4 and to prevent the leakage of the magnetic field to the outside.

The outer diameter of the hub 8 is smaller than the outer diameter of the recess 4a formed on the upper surface of the turntable 4, and as shown in FIG.
When the disk 1 is mounted in a state where the disk 1 is fitted into the positioning portion 9a of the rotary shaft 9, the hub 8 is housed in the recess 4a. The substrate 6 having the information recording layer 5 of the disc 1 is brought into direct contact with the annular table surface 4b on the outer side of the turntable 4.

Then, the substrate 6 having the information recording layer 5 of the disc 1 is surely pressed against the turntable 4 so that the shake in the direction perpendicular to the surface of the substrate 6 is minimized, whereby stable information recording is achieved. It has a structure that allows reproduction.

If the hub 8 and the table surface 4b of the turntable 4 are in contact with each other, it is necessary to make the parallelism between the surface of the hub 8 and the surface of the substrate 6 extremely accurate, and the swing of the disk 1 may occur. Since it becomes large, the thickness of the hub 8 and the thickness of the adhesive must be made uniform, which is an extremely difficult work.

On the other hand, the length of the centering portion 9a of the rotary shaft 9 of the medium driving means 3 is limited to the length that fits only with the central hole 10 of the hub 8 on the turntable 4 side. 8, central hole 10,
It is configured so that the coaxiality of 10 does not matter so much.

In addition, making the inner diameters of the two substrates 6, 6 and the center holes 10, 10 of the two hubs 8, 8 coaxial is a difficult task, and the length of the centering portion 9a is longer than necessary. If it is too long, it will take a long time to be mounted on the turntable 4, and in addition, it will cause a problem in terms of wear.

Further, since the magnetic circuit is formed in the concave portion 4a of the turntable 4, magnetic leakage to the outside is minimized, so that magnetic powder such as iron powder adheres to the rotating shaft 9. The hub 8 can be prevented from being improperly fitted.

Further, a proper gap G is formed between the magnet 12 and the yoke 13 housed in the concave portion 4a of the turntable 4 and the hub 8 so that the substrate 6 of the disk 1 and the table surface 4b come into direct contact with each other. Has become. In addition, the gap G
Means to reliably transmit the driving force of the turntable 4 to the disc 1 and, moreover, to the cartridge 2 accommodating the disc 1
This is because the disc 1 is mounted with an appropriate suction force (mounting force) with which the disc 1 can be easily removed from the turntable 4 simply by raising.

Reference numeral 15 shown in FIG. 2 is a motor mounting frame of the medium driving means 3, and 16 is a control board for controlling the driving of the motor 11.

Reference numeral 17 shown in FIG. 3 denotes a head which is moved in the radial direction of the disk 1 by a head moving means such as a linear motor (not shown), and is a lower surface side substrate of the information storage medium 1 mounted and driven by the medium driving means 3. Information processing such as recording or reproducing is performed on the information recording layer 5 formed in 6.

In the above-described embodiment, the yoke 13 of the magnetic circuit forming member 14 housed in the recess 4a of the turntable 4 for magnetically attracting the information storage medium of the present invention is provided on both the inner diameter portion and the outer diameter portion. Although the structure having the upper portions 13a and 13b has been described, the present invention is not limited to this, and the rising portion may be provided only on one of the inner diameter portion and the outer diameter portion, for example.

Further, the center hub 8 as a member to be attracted, which is attached to the center of rotation of the disk 1, is not limited to the shaving process, but may be, for example, a press process.

[Effects of the Invention] As described above, the present invention is mounted on a turntable that accommodates a magnetic circuit forming member that forms a magnetic circuit in a recess, and is driven to rotate. An information storage medium having a recording layer and a substrate, to which is attached a magnetically attracted member having a center hole that serves as a rotation center, the member being fitted to the information storage medium. And the dimension of the protrusion is set smaller than the thickness of the substrate of the information storage medium. Therefore, since the information storage medium can be magnetically attached to the turntable by suction, it is possible to eliminate the need for a clamper, which is an obstacle to thinning, weight reduction, and cost reduction of the device, which is conventionally required. Becomes Also,
The dimension of the positioning convex portion of the member to be attracted is set to be smaller than the thickness of the substrate of the information storage medium so that it can be fitted only to a good portion, not a poor finished state caused by the molding conditions of the substrate. As a result, it is possible to obtain an information storage medium that is easily obtained with good eccentricity accuracy and that enables stable information processing without eccentricity.

[Brief description of drawings]

1 to 5 show an embodiment of the present invention.
The figure is a cross-sectional view showing a mounted state of a hub, which is a main part, FIG. 2 is a schematic configuration explanatory view showing a partial cross-section of an unmounted state of an information storage medium, and FIG. 3 is a state mounted with an information storage medium. FIG. 4 is an explanatory view showing a state of the disk substrate during molding, FIG. 5 is an enlarged sectional view showing a state of the inner diameter portion of the disk substrate after molding, FIG. 6 and FIG. FIG. 6 is a schematic cross-sectional view showing a mounted state of a conventional example. 1 ... Information storage medium (disk), 4 ... Turntable, 4a ... Recess, 8 ... Suction target (hub), 8 ... Convex, 10 ... Center hole, 14 ... Magnetic circuit forming member .

Claims (1)

[Claims] 1. An information storage medium which is mounted on a turntable containing a magnetic circuit forming member for forming a magnetic circuit in a recess and is driven to rotate. The information storage medium has an opening at the center of rotation and faces each other. A substrate having a recording layer and a convex portion having a dimension set smaller than the thickness of the substrate, and the convex portion is fitted into the opening of the substrate, so that the non-opposing surface of the substrate is An information storage medium, comprising: a member to be attached, which is magnetically attracted to the turntable side.