JP2543860B2 - Information storage medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention drives an information storage medium such as an optical disk, and records and reproduces information by using a laser beam or the like during its rotation. , Or to improvement of an information storage medium used in an information processing apparatus that performs information processing such as erasing.

(Prior Art) In recent years, an information processing device using an optical disk as a storage medium is
Compared with magnetic information processing devices that have been widely used in the past, the information storage capacity can be greatly increased, and extremely good and stable information reproduction with less noise can be obtained and external influences can be reduced. It is being widely used because it is hard to receive and has a very stable storage state, and can perform information processing in a non-contact state and has no adverse effects such as damage to the storage medium and the information processing head.

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 apparatus, as shown in FIGS. 5 and 6, when the information storage medium (optical disc) a is fixed to the turntable b, the information storage medium (optical disc) a
Is clamped to the turntable b side via the clamper c.

6 shows a structure in which a pressing force is applied to a clamper c through a supporting means e having an urging member d such as a spring, and the one shown in FIG. 6 has a magnet f on 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.

However, in such a conventional device, not only the clamper c is required but also the drive space required to move the clamper c must be formed.
Further, a mechanism for bringing the clamper c into and out of contact 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.

The former (Fig. 5) is a turntable b.
Since it always receives a force, the turntable b and the rotary shaft g integral with the turntable b must be made rigid, and the latter (FIG. 6) depends on the thickness of the information storage medium a. There is a problem in that the clamping force varies, and in the case of a relatively thick information storage medium a such as two substrates h bonded together, it may not be possible to reliably clamp.

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 for a long time, and the center and the rotation center of the pre-groove (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.

Therefore, in recent years, in order to solve this problem, a device shown in FIG. 7 has been considered as a device that can be mounted without using a clamper, which is an obstacle to reduction in thickness, weight and cost. This is a metal plate n having a central hole m in a substrate h.
Is used with an adhesive, and the information storage medium a is magnetically attracted to the turntable b side by a magnet f embedded in the turntable b.

However, this is a substrate h with a different coefficient of thermal expansion.
Since the metal plate n and the metal plate n are directly adhered by an adhesive, when heat is affected by an external temperature change or the like, a force is applied to the vicinity of the inner diameter portion of the substrate h due to the difference in thermal expansion coefficient between them. Is added to the substrate h, so that the substrate h is slightly distorted. The distortion of the substrate h is caused by the optical characteristics of the substrate h (especially birefringence).
However, there is a problem in that the recording / reproducing of information is adversely affected.

(Problems to be Solved by the Invention) As described above, it is possible to mount the device without using the clamper, which causes obstacles such as thinning, weight reduction, and cost reduction, and regardless of the thickness of the information storage medium. Even in the structure shown in FIG. 7 having the features, the substrate h having a different thermal expansion coefficient is used.
Since the metal plate n and the metal plate n are directly adhered with an adhesive, when the substrate is affected by heat due to an external temperature change or the like, a slight distortion occurs in the substrate h due to the difference in the thermal expansion coefficient, There is a problem that it affects the optical characteristics (particularly the birefringence index) of the substrate h, and particularly has a great adverse effect on the storage / reproduction of information.

The present invention has been made based on the above circumstances, and an object thereof is that it can be easily and surely mounted without using a clamper that is an obstacle to cost reduction and the like.
An object of the present invention is to provide an information storage medium capable of preventing distortion of a substrate due to thermal influence and capable of stable information processing.

[Structure of the Invention] (Means for Solving Problems) In order to solve the above problems, the present invention is fitted to a rotary shaft of a rotation driving means and provided on a turntable of the rotation driving means. An information storage medium that is magnetically attracted by a magnetically formed member and is rotated while being supported by a turntable, a substrate having a rotation center, and a substrate integrally formed with the substrate and positioned at the rotation center. The centering member, which is composed of a convex portion and has a central hole that fits with the rotary shaft at the center of the convex portion, and the substrate and the centering member are formed of materials having different thermal expansion coefficients, and A magnetic member magnetically attracted by the magnetic forming member,
The magnetic member is attached to the centering member in a state where movement of the magnetic member in a direction perpendicular to the surface of the substrate is restricted with respect to the centering member and a slight movement in a direction parallel to the surface of the substrate is allowed. Mounting means attached to the centering member, the mounting means including a locked portion formed on the centering member, and a locking claw formed on the magnetic member and engaged with the locked portion. It is characterized by that.

(Operation) That is, according to the present invention, with the above configuration,
Since the information storage medium can be magnetically attached to the turntable by magnetic attraction, it is possible to attach the information storage medium without the need for a clamper, which is an obstacle to the conventional thinning, weight reduction, and cost reduction of the device. Is possible. Further, since the attracted member attached to the central portion of the substrate is composed of the centering member integrated with the substrate and the magnetic member attached to the centering member, there is a difference in thermal expansion coefficient between the substrate and the magnetic member. The distortion of the substrate can be prevented, and stable information processing can be performed.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In FIGS. 1 and 2, reference numeral 1 denotes an information storage medium (hereinafter referred to as a disk) housed in the cartridge 2,
The disc 1 is designed to be inserted together with the cartridge 2 into a medium insertion / ejection opening formed in the main body (not shown) of the information processing apparatus.

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 automatically mounted on the turntable 4 of the medium driving means 3 of the disk 1.

The disc 1 comprises two substrates having an information recording layer 5.
6, 6 are adhered by sandwiching an inner spacer 7 and an outer spacer (not shown) so that the information recording layers 5, 5 are on the inner side, and a member 8 to be attracted which is magnetically attracted to both surfaces of the inner diameter portion. It has a structure with 8 attached.

The substrates 6, 6 are made of injection-molded transparent plastic plates, and are adhered to the inner spacer 7 and the outer spacer via an ultraviolet curable adhesive.

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 by a disk-shaped convex portion integrally formed with the center of rotation of the substrate 6, and the medium driving means 3 is formed in the center.
Has a center hole 10 that fits with the centering portion 9a of the rotating shaft 9 of the rotary shaft 9 and is precisely formed coaxially with a recording / reproducing pre-groove (not shown) formed on the substrate 6. Therefore, it is possible to prevent problems such as a decrease in recording / reproduction accuracy and an increase in access time, which are caused by the eccentricity.

Further, the magnetic member 21 is formed from a metal plate into a disc shape having a through hole 21a in the central portion, and is fitted into the annular recess 20b formed on the upper surface of the centering member 20 to be slightly larger than this. The substrate 6 is in an embedded state and via a mounting means 22 described later.
Is constrained to move in a direction perpendicular to the surface of the substrate 6 and is attached so as to be slightly movable in a direction parallel to the surface of the substrate 6.

As shown in FIGS. 3 and 4, the mounting means 22 includes three locked portions 23 formed on the centering member 20 so as to be positioned at the same center circle at equal intervals, and these locked portions. Stop 23
The magnetic member 21 has locking claws 24 formed to have the same positional relationship as the locked portions 23.

The locked portion 23 has a claw insertion hole 23a formed to have a size capable of inserting the locking claw 24 and a slit portion 23b formed in a state of communicating therewith, and the slit portion 2
A return preventing protrusion 23c is formed on the lower surface of one side edge of 3b.

On the other hand, the locking claw 24 is a cut and raised tongue piece bent in an L shape.
21a.

For attachment, first, the locking claws 24 formed on the magnetic member 21 are engaged with the claw insertion holes 23a of the centering member 20.
Then, the magnetic member 21 is rotated clockwise in the state shown in FIG. 4 so that the vertical portion 24a of the locking claw 24 intervenes in the slit portion 23b. 23b is locked to the lower surface of one side edge.
At this time, the horizontal portion 24b of the locking claw 24 is elastically deformed to get over the return prevention protrusion 23c formed on the lower surface of one side of the slit portion 23b, and is prevented from returning to the claw insertion hole 23a ... direction. The protrusion 23c does not interfere and return.

In this way, the magnetic member 21 attached to the centering member 20 is perpendicular to the surface of the substrate 6 by locking the horizontal portion 24b of each locking claw 24 to the lower surface of one side edge of the slit 23b. The movements in the different directions are restrained, and it is possible to slightly move in the direction parallel to the surface of the substrate 6 by the gap formed between the slit portion 23b and the vertical portion 24a.

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

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 forming member 14 including a magnet 12 and a yoke 13 for magnetically attracting the attracted member 8 of the information storage medium 1 is accommodated 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.

Further, the attracted member 8 is formed such that the outer diameter D ₁ thereof is smaller than the inner diameter D _{2 of the} concave portion 4a formed to accommodate the magnetic forming member 14 on the upper surface of the turntable 4.
As shown in the figure, when the disk 1 is mounted with the center hole 10 of the member to be attracted 8 fitted to the positioning portion 9a of the rotary shaft 9, the member to be attracted 8 is housed in the recess 4a. Has become. The substrate 6 having the information recording layer 5 of the disc 1 is an annular table surface outside the turntable 4.
It comes into direct contact with 4b.

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.

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 attracted member 8 on the turntable 4 side, and the length of the two covered portions is reduced. Suction member 8,
It is configured so that the coaxiality of the eight central holes 10 and 10 does not matter so much.

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. It is possible to prevent the sucked member 8 from not fitting properly.

In addition, the magnet housed in the recess 4a of the turntable 4
An appropriate gap G is formed between the suction member 8 and the yoke 12 and the suction target member 8 as shown in FIG. 2, and the substrate 6 of the disk 1 and the table surface 4b are in direct contact with each other. . Further, the gap G is suitable for surely transmitting the driving force of the turntable 4 to the disc 1 and for easily removing the disc 1 from the turntable 4 only by raising the cartridge 2 accommodating the disc 1. This is because the disc 1 is mounted with a sufficient suction force (mounting force).

Reference numeral 15 shown in FIGS. 1 and 2 is the medium driving means 3.
Is a motor mounting frame, and 16 is a control board for controlling the drive of the motor 11.

Reference numeral 17 shown in FIG. 2 is a head that moves 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 that is 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.

Thus, the disk 1 having the above-described structure, which includes the substrate 6 and the attached attracted member 8 provided in the central portion of the substrate 6, has the turntable 4 in which the magnetic forming member 14 is housed.
Since it is possible to magnetically attach to the side, the thickness of the disk 1 can be reduced without using a clamper which is an obstacle to thinning, weight reduction and cost reduction of the device which has been conventionally required. It can be installed regardless. Also, the substrate 6
Since the attracted member 8 provided in the central part of the is composed of the centering member 20 having the central hole 10 as the center of rotation in the central part and the magnetic member 21 attached to the centering member 20,
Even when the substrate 6 and the magnetic member 21 are affected by heat due to a change in the external temperature, the influence of the difference in the thermal expansion coefficient between the substrate 6 and the magnetic member 21 can be absorbed in this portion, and the substrate 6 is not distorted unlike the conventional case. Therefore, stable information processing can be performed.

Further, since the centering member 20 is integrally molded with the substrate 6, it is possible to omit the formation of the fitting convex portion on the inner diameter portion of the substrate, which requires high accuracy as in the case where the centering member 20 is formed by another member. It is possible to save the labor of bonding to the substrate and provide a highly accurate one at a low cost.

In the above-described embodiment, the magnetic forming member 14 for magnetically attracting the information storage medium 1 of the present invention is composed of the magnet 12 and the yoke 13, and the yoke 13 rises on both the inner diameter portion and the outer diameter portion. Although the configuration having 13a and 13b has been described, the present invention is not limited to this, and may have a rising portion only in the inner diameter portion, or may have a rising portion only in the outer diameter portion. It may be one. Further, the magnetism forming member 14 may be composed of only the magnet 12 excluding the yoke 13.

In addition, it goes without saying that the present invention can be variously modified and implemented without departing from the spirit of the present invention.

[Effects of the Invention] As described above, the present invention is mounted on a turntable accommodating a magnetic forming member and is driven to rotate, and a magnetically attracted member is provided on the turntable side. In the information storage medium described above, the member to be attracted includes a centering member integrally formed on the substrate with a center hole serving as a center of rotation in the center, and a magnetic member attached to the centering member. It is equipped with. Therefore, since the information storage medium can be magnetically attached to the turntable by suction, the information storage medium can be attached without the need for a clamper, which is an obstacle to the thinning, weight reduction, and cost reduction of the conventional device. It becomes possible to do. Further, since the attracted member attached to the central portion of the substrate is composed of the centering member integrally formed on the substrate and the magnetic member attached to the centering member, the thermal expansion coefficient of the substrate and the magnetic member The substrate can be prevented from being distorted due to the difference, and stable information processing can be achieved.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention.
FIG. 2 is a schematic sectional view showing a partially cross-section of an information storage medium in an unmounted state, FIG. 2 is a schematic sectional view showing a partially sectional view of a state in which an information storage medium is mounted, and FIG. FIG. 4 is a plan view of a member to be attracted, which is a main part, FIG. 4 is an exploded perspective view showing a mounting means of a magnetic member and a centering member that constitutes the member to be attracted, and FIGS. It is a schematic sectional drawing which shows the mounting state of a prior art example. 1 ... information storage medium (disk), 4 ... turntable, 6 ... substrate, 8 ... attracted member, 10 ... central hole, 12
...... Magnet, 14 ...... Magnetic forming member, 20 ...... Centering member, 21
...... Magnetic member, 22 ...... Mounting means, 23 ...... Engagement part, 24
...... Locking claw.

Front page continuation (72) Inventor Nobuo Inage 70 Yanagicho, Sachi-ku, Kawasaki-shi In Toshiba Automatic Engineering Co., Ltd. (56) Reference JP-A-61-208684 (JP, A)

Claims (2)

(57) [Claims] 1. Information that is fitted to a rotary shaft of a rotary drive means and is magnetically attracted by a magnetic forming member provided on a turntable of the rotary drive means to be rotated while being supported by the turntable. In a storage medium, a core having a rotation center portion and a convex portion integrally formed with the substrate and located at the rotation center portion, and a core having a central hole that fits with the rotation shaft at the center portion of the convex portion. The centering member, the substrate and the centering member are formed of materials having different thermal expansion coefficients, and the magnetic member magnetically attracted by the magnetic forming member, and the magnetic member to the centering member. On the other hand, in a state where the movement in the direction perpendicular to the surface of the substrate is restrained and a slight movement in the direction parallel to the surface of the substrate is allowed, the attachment means attached to the centering member, The above Only means, said a-be-engaged portion formed on the centering member, the information storage medium, characterized in that formed in the magnetic member and a locking pawl engaged with the engaged portion. 2. The engaging claw is formed by an L-shaped tongue having a vertical portion extending from the magnetic member and an elastically deformable horizontal portion, and the engaged portion. Includes an insertion hole through which the locking claw is inserted, a slit portion that communicates with the insertion hole and in which the vertical portion is interposed with a predetermined gap, and a slit formed on a lower surface of one side edge of the slit portion. When the horizontal portion is interposed in the portion, the horizontal portion is elastically deformed to get over, and a prevention protrusion that restricts the movement of the locking claw in the insertion hole direction is provided. By engaging with the lower surface of one side edge of the slit portion, the movement of the magnetic member in the direction perpendicular to the surface of the substrate is restrained with respect to the centering member, and the vertical portion is the slit portion. The magnet in the direction parallel to the surface of the substrate with respect to the centering member by a predetermined gap. Information storage medium according to paragraph 1 claims, characterized in that to permit movement of the member.