JPS62222475A - Information storage medium - Google Patents

Abstract

PURPOSE:To make a clamper unnecessary by which a disk is loaded on a turntable, and to prevent distortion due to thermal expansion in a disk substrate from generating, by constituting the member to be attracted of a disk adhered magnetically to the turntable, of a centering member and a magnetic member. CONSTITUTION:A member 8 to be attracted consisting of a centering member 20 and a magnetic member 21 is provided at the inner diameter part of a disk 1, and the member 8 is attracted to a magnetic circuit at the recessed part 4a of the turntable when the disk 1 is loaded on the turntable. A recording/ reproduction is stabilized by restricting the movement of the disk 1 in the upward/downward direction by the horizontal part 24a of a connecting claw, and magnetic leakage to the outside can be prevented by providing the magnetic circuit in the recessed part 4a, and it is prevented that an iron powder is attached on an axis of rotation 9a. Therefore, the clamper is made unnecessary since the disk 1 is adhered on the turntable by the member 8 to be attracted, and the distortion due to the difference of thermal expansion fectors in a substrate 6 and the magnetic member 21 can be prevented, and a stable information processing can be performed.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is directed to recording and reproducing information by driving an information storage medium such as an optical disk and using a laser beam or the like during its rotation. , or information to perform information processing such as deletion [
12! Information records used in l management equipment! Concerning improvements in media.

(Prior Art) In recent years, information processing devices using optical disks as storage media have been able to significantly increase the information storage capacity and have less noise compared to conventionally widely used magnetic information processing devices. Not only is the information reproduced in an extremely good and stable state, the storage state is extremely stable as it is not easily affected by external influences, and information processing can be performed in a non-contact state, preventing damage to the storage medium and information processing head. It is increasingly being used because it has features such as no adverse effects.

In addition, with this trend toward increased use, there has recently been a demand for this type of information processing equipment, such as information recording/reproducing devices, to be as thin, lightweight, and cost-effective as possible.

On the other hand, in the conventional apparatus, as shown in FIGS. 6 and 7, an information storage medium (optical disk) a is placed on a turntable b.
When fixing the information storage medium (optical disc) a to the turntable b! via the clamper C! It is configured to be pressed down to 1IIIl.

The structure shown in FIG. 6 is configured to apply a pressing force to the clamper C via a support means e separated by a biasing body d such as a spring, and the structure shown in FIG. A magnetic attraction force is generated between the clamper C and the turntable b made of a magnetic material, which applies a pressing force to the clamper C.

However, in all of these conventional devices, not only the clamper C is required, but also a movement space necessary for moving the clamper C must be created, and there is also a need to move the clamper C toward and away. A mechanism etc. is required. For this reason, the structure of this part is complicated and large, which not only becomes a major obstacle to reducing thickness, weight, and cost, but also makes assembly difficult.

There were problems such as troublesome maintenance.

Furthermore, in the former case (Fig. 6), since turntable b is always under force, turntable b and the rotating shaft Q that is integral with it must be made strong.
In addition, in the case of the latter (Fig. 7), the clamping force varies depending on the thickness of the information storage medium a, and if the information storage medium a is relatively thick, such as two substrates pasted together, There is a problem in that there are cases where it cannot be held.

Further, conventionally, the inner diameter portion i of the information storage medium a, that is,
The inner diameter part of the synthetic resin substrate is directly fitted into a positioning part j formed on the turntable b side for positioning. Therefore, the diameter of the inner diameter portion i of the information storage medium a may change due to wear over a long period of time.
There is a serious problem that the eccentricity between the center of the pre-group (not shown) formed in a spiral shape at a pitch of 1.6 pn on the substrate and the center of rotation becomes large, which adversely affects the recording/reproduction of information. .

Therefore, in order to solve this problem, we have recently made it thinner.

A device as shown in FIG. 8 has been considered as a device that can be installed without using a clamper, which is an obstacle to reducing weight and cost. This uses an information storage medium a in which a metal plate n with a center hole m is attached to a substrate with adhesive, and this information storage medium a is magnetically placed on the turntable b side by a magnet f embedded in a turntable b. It has a structure that attracts a lot of people.

However, since this product has a structure in which the substrate and metal plate n, which have different coefficients of thermal expansion, are directly attached with adhesive, these coefficients of thermal expansion will change when affected by heat due to external temperature changes, etc. Due to the difference in pressure, a force is applied near the inner diameter of the board, causing a slight distortion in the board. This distortion of the substrate affects the optical properties (particularly the birefringence) of the substrate, and there is a problem in that it has a particularly bad effect on the recording/reproducing of information.

(Problems to be Solved by the Invention) As described above, the information storage medium can be mounted regardless of its thickness without the use of a clamper, which is an impediment to thinning, lightweighting, and cost reduction. Even in the structure shown in Fig. 8, which has the feature of When exposed to heat, a slight distortion occurs in the substrate due to the difference in thermal expansion coefficient, which affects the optical properties (especially birefringence) of the substrate, and has a particularly negative effect on recording/reproducing information. There's a problem.

The present invention has been made based on the above circumstances, and its purpose is to easily and reliably attach eight pieces without using a clamper, which would be an obstacle such as increasing costs, and to avoid distortion of the board due to thermal effects. The purpose of the present invention is to provide an information storage medium that can prevent the occurrence of problems and perform stable information processing.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a turntable that is mounted on a turntable that accommodates a magnetic circuit forming member that forms a magnetic circuit in a concave portion and is driven to rotate. This is an information storage medium in which an attracted member that is magnetically attracted toward the turntable is attached to the rotational center of a substrate, the attracted member having a center hole at the center that is the rotational center. The centering member includes a centering member that fits into the inner diameter portion of the substrate, and a magnetic member attached to the centering member.

(Function) That is, with the above configuration, the present invention enables the information storage medium to be magnetically attached to the turntable, thereby making the device thinner, lighter, and less expensive than conventionally required devices. It becomes possible to install the clamper without the need for a clamper, which is an obstacle such as cost reduction. In addition, since the attracted member attached to the center of the board consists of a centering member and a magnetic member attached to the centering member, distortion of the board due to the difference in thermal expansion coefficient between the board and the magnetic member can be avoided. This enables stable information processing.

(Example) An example of the present invention will be described below with reference to FIGS. 1 to 5. In the figure, 1 is an information storage medium (hereinafter referred to as a disk) housed in a cartridge 2, and this disk 1 is an information storage medium (hereinafter referred to as a disk). ! The cartridge 2 is inserted together with the cartridge 2 into a medium insertion/ejection opening formed in the main body (not shown) of the processing apparatus.

The disk 1 inserted together with the cartridge 2 is automatically taken into a predetermined position and in a horizontal state by a medium take-in/loading mechanism (not shown), and at this time, the cartridge 2 is placed so that a part of the disk 1 is exposed. The center of rotation becomes open. Thereafter, the cartridge 2 is displaced in the plane direction, and the disk 1 is automatically mounted on the turntable 4 of the medium drive means 3.

The disk 1 includes two substrates 6 having an information recording layer 5.
, 6 are glued together with an inner spacer 7 and an outer spacer (not shown) in between so that the information recording layer 5.5 is on the inside, and an attracted member 8. 6 is magnetically attracted to both surfaces of the inner diameter portion. 8 is attached.

The substrate 6.6 is made of an injection-molded transparent plastic plate, and is bonded to the inner spacer 7 and the outer spacer via an ultraviolet curing adhesive.

Further, as shown in FIGS. 3 and 4, the attracted member 8 includes a centering member 20 and a magnetic member 21 attached to the centering member 20.

The centering member 20 is formed of a synthetic resin material into a disk shape, and has a centering portion 9 for the rotation shaft 9 of the medium drive means 3 in the center.
a convex portion 20a that has a center hole 10 that fits into the inner diameter portion 6a of the substrate 6, and has a convex portion 20a on the lower surface side that fits into the inner diameter portion 6a of the substrate 6.
It has a shape with .

Then, by fitting the outer diameter portion of the convex portion 20a into the inner diameter portion 6a of the substrate 6, positioning is performed with respect to the substrate 6, and in this state, the substrate 6.6 is adversely affected by the substrate 6.6. It is designed to be bonded with an adhesive such as an epoxy adhesive.

In order to shorten the processing time, the substrate 6 has an inner diameter portion 6a, which is a center hole, formed at the same time, and a stepped portion 6b is formed in the inner diameter portion of the substrate 6, as shown in FIG. This occurs because the resin at the gate portion is peeled off when cut by a punch during molding, and the step portion 6b protrudes from the surface opposite to the outer surface of the substrate 6 so that its inner diameter becomes smaller.

Although this stepped portion 6b is slightly uneven, it is not smooth and has poor accuracy.

In this way, since the inner diameter portion of the substrate 6 has better precision on the outer surface of the substrate 6, the centering member 20 is used as shown in FIG.
The height dimension h1 of the convex portion 20a is set smaller than the thickness dimension h2 of the substrate 6, and the centering member 20 is applied only to the part with high precision.
The convex portions 20a are fitted to maintain good positional accuracy with little eccentricity.

The inner diameter portion 6a of the substrate 6 is precisely molded to be coaxial with a pre-group for recording and reproduction (not shown) formed on the substrate 6, and the convex portion 2 of the centering member 20
The outer diameter portion of the centering member 20 and the center hole 10 of the centering member 20 are precisely machined to be coaxial, so that the center of the pre-group and the rotational axis of the rotational shaft 9 can be aligned. This makes it possible to prevent problems such as a decrease in recording/reproducing accuracy and an increase in access time caused by eccentricity.

In addition, the magnetic member 21 has a through hole 21a in the center part from the metal plate.
The centering member 20 is fitted into an annular recess 20b formed on the upper surface of the centering member 20, and is attached to the substrate 6 via means 22 for attachment (described later). The movement in the direction perpendicular to the plane of the substrate 6 is restrained.
It is mounted so that it can move slightly in the direction parallel to the plane of the

As shown in FIGS. 4 and 5, the mounting means 22 includes three locked portions 23 formed on the centering member 20 so as to be located on the same central circle at equal intervals, It consists of locking claws 24 formed on the magnetic member 21 so as to be in the same positional relationship as the locked parts 23 to engage with these locked parts 23.

The locked portion 23 has a claw insertion hole 23a formed in a size that allows the locking claw 24 to be inserted through it, and a slit portion 23b formed in communication with the hole, and one side of the slit portion 23b. There is a return prevention protrusion 23c on the lower surface.
has been formed.

On the other hand, the locking pawl 24 is formed by a cut-and-raised tongue piece 21a bent into an L-shape.

Therefore, when installing, first, the locking claws 24 formed on the magnetic member 21 are inserted into the claw insertion holes 23a of the centering member 20, and then the magnetic member 21 is inserted as shown in FIG. In this state, by rotating the locking pawl 24 clockwise so that the vertical portion 24a of the locking pawl 24 is interposed in the slit portion 23b, the horizontal portion 24b is locked to the lower surface portion of one side of the slit portion 23b. do. At this time, the horizontal portion 24b of the locking pawl 24 is elastically deformed and goes over the return prevention protrusion 23c formed on the lower surface of one side of the slit portion 23b, and attempts to return to the direction of the pawl insertion hole 23a... The prevention protrusion 23c will not get in the way and will not return.

In this way, the magnetic member 21 attached to the centering member 20 is fixed to the substrate 6 by the horizontal portion 24b of each locking claw 24 being locked to the lower surface of one side edge of the slit portion 23b.
The movement in the direction perpendicular to the plane of the substrate 6 is restricted, and the gap valve formed between the part 23b and the vertical part 24a is allowed to move slightly in the direction parallel to the plane of the substrate 6. .

Further, the medium driving means 3 includes an outer rotor type brushless DC motor 11 having a motor shaft as the rotation shaft 9, and a turntable 4 attached to the rotation shaft 9 of the motor 11. ing.

The turntable 4 is made of a non-magnetic metal material, and has a recess 4a formed on its upper surface. A magnetic circuit forming member 14 consisting of a magnet 12 and a yoke 13, which magnetically attract the attracted member 8 of the information storage medium 1, is housed in the recess 4a.

This is to ensure that sufficient force is exerted to mount the disc 1 on the turntable 4 and to prevent leakage of magnetism to the outside.

Further, the attracted member 8 has an outer diameter D1 smaller than an inner diameter D2 of the recess 4a formed on the upper surface of the turntable 4 to accommodate the magnetic circuit forming member 14, as shown in FIG. As shown, when the disk 1 is mounted with the center hole 10 of the attracted member 8 fitted into the positioning portion 9a of the rotating shaft 9, the attracted member 8 is accommodated in the recess 4a. There is. The substrate 6 having the information recording layer 5 of the disc 1 is brought into direct contact with the outer annular table surface 4b of the turntable 4.

Then, the substrate 6 having the information recording layer 5 of the disk 1 is firmly pressed against the turntable 4, and the vibration in the direction perpendicular to the surface of the substrate 6 is minimized, thereby stably recording information. It has a configuration that allows playback.

If the structure is such that the member to be attracted 8 and the table surface 4b of the turntable 4 are in contact with each other, the parallelism between the surface of the member to be attracted 8 and the surface of the substrate 6 must be made very precisely. 1, the thickness of the suction target member 8 and the thickness of the adhesive must be made uniform, which is an extremely difficult task.

On the other hand, the length of the centering part 9a of the rotating shaft 9 of the medium drive means 3 is limited to a length that fits only the center hole 10 of the attracted member 8 on the turntable 4 side, and The configuration is such that the coaxiality of the center holes 10° 10 of the suction members 8, 8 does not pose much of a problem.

Note that it is quite difficult to make the inner diameter parts of the two substrates 6.6 and the center holes 10.10 of the two suction members 8.8 coaxial, and the length of the centering part 9a is If it is longer than necessary, it will take time to attach it to the turntable 4, and this will cause problems in terms of wear and the like.

In addition, since a magnetic circuit is formed in the recess 4a of the turntable 4, magnetic leakage to the outside is minimized, so powder of magnetic materials such as iron powder may adhere to the rotating shaft 9. This makes it possible to prevent the suction target member 8 from failing to fit properly.

Furthermore, between the magnet 12 and yoke 13 housed in the recess 4a of the turntable 4 and the attracted member 8,
As shown in FIG. 2, a suitable gap G is formed so that the substrate 6 of the disk 1 and the table surface 4b are brought into direct contact. In addition, the above-mentioned gap G is an appropriate gap that allows the driving force of the turntable 4 to be reliably transmitted to the disk 1, and also allows the disk 1 to be easily removed from the turntable 4 by simply lifting the cartridge 2 containing the disk 1. This is to mount the disc 1 with a strong suction force (mounting force).

Note that 15 shown in FIGS. 10 and 2 is the medium driving means 3.
The motor is mounted on the frame, and 16 is a control board for controlling the drive of the motor 11.

Further, 17 shown in FIG. 2 is a head that moves in the radial direction of the disk 10 by a head moving means such as a linear motor (not shown), and the lower substrate 6 of the information storage medium 1 is attached to the medium driving means 3 and driven. Information processing, such as recording or reproduction, is performed on the information recording layer 5 formed on the substrate. □ Therefore, the disk 1 configured as described above, which is composed of the substrate 6 and the attracted member 8 attached to the center of the substrate 6, is magnetically attracted and attached to the turntable 4 side that houses the magnetic circuit forming member 14. This makes it possible to reduce the thickness, weight, and cost of the device, which was required in the past, without using a clamper.
It can be installed regardless of the thickness. In addition, a centering member 20 having a center hole 10 serving as a rotation center at the center of the suction member 8 attached to the center of the substrate 6 and a convex portion 20a that fits with the inner diameter portion 6a of the substrate 6; Since it is composed of the magnetic member 21 attached to the centering member 20, even if it is affected by heat due to an external temperature change, etc., this part will not be affected by the difference in coefficient of thermal expansion between the substrate 6 and the magnetic member 21. This allows stable information processing to be performed without causing distortion in the substrate 6 as in the conventional case.

In the above embodiment, the yaw 13 of the magnetic circuit forming member 14 accommodated in the recess 4a of the turntable 4 that magnetically attracts the information storage medium of the present invention is 1 yen.
Although the explanation has been made regarding a structure having the raised parts 13a and 13b on both the inner diameter part and the outer diameter part, the structure is not limited to this. It is also possible to have an upright portion only on the outer diameter portion.

Further, although the material of the centering member 20 is made of synthetic resin, it is not limited to this. In other words, since it is sufficient to use a material with a coefficient of thermal expansion comparable to that of the material of the substrate 6, the material should be determined according to the material of the substrate 6. For example, if the substrate 6 is made of glass, the centering member should be determined according to the material of the substrate 6. 20 may be made of glass, ceramics, or the like.

In addition, it goes without saying that the present invention can be modified in various ways without changing the essential parts of the present invention.

[Effects of the Invention] As explained above, the present invention is mounted on a turntable containing a magnetic circuit forming member for forming a magnetic circuit in a recessed portion and driven to rotate, and the turntable is mounted at the center of rotation of the substrate. An information storage medium having a magnetically attracted member attached to the side thereof, the member having a center hole in the center serving as a center of rotation, and a core that fits into the inner diameter portion of the substrate. The centering member includes a centering member and a magnetic member attached to the centering member. Therefore, since the information storage medium can be magnetically attracted and attached to the turntable, the information storage medium can be attached to the turntable without the need for a clamper, which is an obstacle to making the device thinner, lighter, and lower in cost, which was previously required. It becomes possible to do so.

In addition, since the attracted member attached to the center of the board is composed of a centering member and a magnetic member attached to the centering member, the difference in thermal expansion coefficient between the board and the magnetic member causes This has the effect of preventing distortion and enabling stable information processing.

[Brief explanation of drawings]

Figures 1 to 5 show one embodiment of the present invention.
2 is a schematic structural explanatory diagram showing a state in which the information storage medium is not packaged in a tube with a partial cross section; FIG. Fig. 3 is an enlarged view of the main part, Fig. 4 is a plan view of the main part of the attracted member, and Fig. 5 is an exploded perspective view showing the means for attaching the centering member and magnetic member that constitute the attracted member. , FIGS. 6 to 8 are schematic cross-sectional views showing the mounting states of different conventional examples and prior art examples, respectively. DESCRIPTION OF SYMBOLS 1... Information storage medium disk), 4... Turntable, 4a... Recessed part, 8... Attracted member, 10...
... Center hole, 14... Magnetic circuit forming member, 20...
Centering member, 21... Magnetic member, 22... Mounting means, 23... Engaged portion, 24... Locking claw. Applicant's Representative Patent Attorney Takehiko Suzue Figure 4 Figure 5 Figure 6 Factors Figure 7 Figure 8 Figure 1. Display of the case Japanese Patent Application No. 61-65144 2, Name of the invention Information storage medium 3, Person making the amendment Relationship to the case Patent applicant (307) Toshiba Corporation (and 1 other person) 4. Agent Chiyoda, Tokyo UBE Building 6, 3-7-2 Kasumigaseki,
Subject of amendment 2, Claims (1) A device that is rotatably driven by being wrapped around a turntable that houses magnetic formation members in its four parts, and is magnetically attracted to the turntable side by the center of rotation of the substrate. An information storage medium having a member to be attracted attached thereto, wherein the member to be attracted has a center hole in the center thereof serving as a center of rotation, and a centering member that fits into an inner diameter portion of the substrate, and the centering member. An information storage medium comprising: a magnetic part attached to a magnetic part; (2) The information storage medium according to claim 1, wherein the outer diameter of the attracted member is set smaller than the inner diameter of the four parts provided on the turntable. (3) The magnetic member is attached to the centering member through means such that its movement in the direction perpendicular to the plane of the substrate is restricted, but it can be moved slightly in the direction parallel to the plane of the substrate. An information storage medium according to claim 1, characterized in that: (4) Claims characterized in that the attachment means comprises a locked portion formed on the centering member and a locking pawl formed on the magnetic member and engaged with the locked portion. The information storage medium according to item 3. (5) The information storage medium according to claim 1, wherein the centering member has a convex portion that fits into the inner diameter portion of the substrate. (6) The information storage medium according to claim 5, characterized in that the height of the convex portion of the centering member that fits into the inner diameter portion of the substrate is set smaller than the thickness of the substrate. .

Claims (6)

[Claims] (1) A device that is mounted on a turntable that houses a magnetic circuit forming member that forms a magnetic circuit in a recess and is driven to rotate, and a member that is magnetically attracted toward the turntable is attached to the center of rotation of the board. The information storage medium is equipped with a centering member that has a central hole in the center that serves as a rotation center of the attracted member and that fits into an inner diameter portion of the substrate, and a centering member that is attached to the centering member. An information storage medium comprising a magnetic member. (2) The information storage medium according to claim 1, wherein the outer diameter of the attracted member is set smaller than the inner diameter of the recess provided in the turntable. (3) The magnetic member is attached to the centering member via an attachment means so that its movement in a direction perpendicular to the plane of the substrate is restricted, but it can move slightly in a direction parallel to the plane of the substrate. The information storage medium according to claim 1, characterized in that: (4) The attachment means comprises a locked portion formed on the centering member and a locking pawl formed on a magnetic member and engaged with the locked portion. The information storage medium according to item 3. (5) The information storage medium according to claim 1, wherein the centering member has a convex portion that fits into the inner diameter portion of the substrate. (6) The information storage medium according to claim 5, characterized in that the height of the convex portion of the centering member that fits into the inner diameter portion of the substrate is set smaller than the thickness of the substrate. .