JPH0561824U - Single-sided playback laser vision disc and compact disc - Google Patents

Abstract

(57) [Summary] [Purpose] A single-sided laser vision disc and a central hole that can be used for a double-sided laser vision disc without using an adapter and that does not cause cracks near the central hole. We propose a compact disc that does not crack near the. [Structure] Reinforcement is carried out by using a reinforcing member only in a central clamp region held by a clamp or by increasing the thickness.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a single-sided reproduction laser vision disc and a compact disc.

[0002]

[Prior Art]

 As shown in FIG. 1, a double-sided reproducing laser vision disc 2 formed by bonding two disc substrates 1a and 1b back to back with information recording surfaces has already been put into practical use.

The double-sided reproduction laser vision disc 2 has a hole 3 in the center. In use, as shown in FIG. 2, the double-sided reproduction laser vision disc 2 is clamped, that is, clamped by the first and second clamp members 4a and 4b made of discs, and the first clamp member 4a is clamped. The double-sided reproduction laser vision disc 2 is rotated by a motor (not shown) connected thereto.

Centering of the disc 2 is performed by fitting a protrusion 4c provided at the center of rotation of the first clamp member 4a into a hole 3 provided in the double-sided reproduction laser vision disc 2.

In addition to the double-sided reproduction laser vision disc, a compact disc in which an information recording surface is provided on one surface of a substrate made of a uniform material has already been put into practical use.

[0006]

[Problems to be solved by the device]

 To play a single-sided playback laser vision disc 5 consisting of a single disk substrate using the playback device for double-sided playback laser vision disc 2, single-sided playback laser vision disc 5 is played back on both sides using an adapter. It may be necessary to have the same thickness as Laser Vision Disc 2.

As the adapter 6, it is possible to use an annular disk whose outer diameter is equal to the outer diameter of the second clamp member 4b and whose inner diameter is equal to the outer diameter of the protrusion 4c of the first clamp member 4a.

In FIG. 3, the single-sided reproduction laser vision disc 5 is held by the first and second clump members 4a and 4b for the double-sided reproduction laser vision disc by using the adapter 6 made of the annular disc. It is a sectional view which passes along the central axis of rotation at the time. In this specification, the region held by the clamp members 4a and 4b is referred to as "clamp region".

As shown in FIG. 3, by using the adapter 6, it is possible in principle to reproduce the information on the single-sided reproducing laser vision disc by using the device for the double-sided reproducing laser vision disc. .. However, it is inconvenient that the adapter 6 still has to be used.

The single-sided reproducing laser disk using the adapter 6 has the following problems. That is, since the single-sided reproducing laser disk is thin, it is difficult to increase the mechanical strength. Therefore, a crack 7 may occur near the central hole 3 as shown in FIG. This phenomenon may occur in compact discs as well.

The present invention is a single-sided reproducing laser disc that does not cause cracks 7 even when formed of a material having relatively low mechanical strength and does not require the use of the adapter 6 when the adapter 6 has to be used. The first problem is to propose the above, and the second problem is to propose a compact disc in which cracks do not occur near the central hole.

[0012]

[Means for Solving the Problems] The first problem is composed of one transparent disk-shaped substrate, information is recorded on one side, and the information is covered with a light-reflecting film. In a single-sided playback laser vision disc that has a circular clamp area for holding by the clamp member and has a hole in the center of the clamp area that has an inner diameter approximately the same as the outer diameter of the protrusion of the clamp, only the clump area is A single-sided playback laser vision disc characterized by being formed thicker than other areas, or a single-sided playback laser vision characterized in that only the clamp area is made of a material different from the material of the other parts. Solved by disk. To make the clamp area thicker, a hole with an inner diameter larger than the outer diameter of the protrusion of the clamp is made inside the clamp area, and it is made of the same or different material as the material of the other area, and the outer diameter of the protrusion of the clamp is increased. It can be realized by fitting and fixing a reinforcing member having a hole with the same inner diameter as the above. It can also be realized by forming only the clamp region thick in the process of making the disc-shaped substrate.

To make only the clamp area different from the material of the other parts, make a hole with an inner diameter larger than that of the clamp protrusion in the clamp area, and make a hole with the same inner diameter as the outer diameter of the protrusion of the clamp in this. It can be realized by fitting and fixing a reinforcing member having. It can also be realized by insert-molding a reinforcing member in the process of making a disk-shaped substrate.

The second problem consists of a single transparent disc-shaped substrate, information is recorded on one side, and the information is covered with a light-reflecting film, and a circular shape for being held by a clamp member at the center of the disc. In a compact disc that has a clamp area and a hole with an inner diameter that is approximately the same as the outer diameter of the clamp protrusion in the center of the clamp area, a disc reinforcing member that is different from the material in other areas It was solved by a compact disc, which is characterized by being installed in the. Making only the clamp area different from the material of the other parts creates a hole with an inner diameter larger than that of the clamp projection in the clamp area, and a reinforcement with an inner diameter that is the same as the outer diameter of the clamp projection. It can be realized by fitting and fixing the member. It can also be realized by insert-molding a reinforcing member in the process of making a disk-shaped substrate.

[0015]

[Work]

 Even in the case of a single-sided reproduction laser disc, only the clamp area at the center is thickly formed, so it is possible to use a device for reproducing a double-sided reproduction laser disc without using an adapter. Since the clamp area is formed thick, stress concentration due to the existence of the central hole and cracking due to the stress due to the clamp do not occur.

In the compact disc according to the present invention, since the central clamp region is made of the reinforcing member, the stress concentration due to the existence of the central hole and the crack caused by the stress due to the clamp do not occur.

In order to shorten the response time of rotation and control of the laser disk and reduce the uneven rotation, it is preferable that the moment of inertia I of the laser disk is small. The single-sided reproducing laser disc according to the present invention is made thick only in the clamp area in the central part or made of a material different from the material in the other parts, and in the compact disc, only the clamp area in the central part is made of reinforcing material. Therefore, the inertia moment I does not increase unnecessarily.

[0018]

【Example】

 FIG. 5 is a conceptual sectional view of an example of a single-sided laser disk according to the present invention.

The circular substrate 8 on one side of which information is recorded is a laser vision such as a polycarbonate synthetic resin, a polyolefin synthetic resin, or a synthetic resin having a norbornene skeleton (trade name ARTON Japan Synthetic Rubber Co., Ltd.). Made of synthetic resin that can be used for disks.

The circular substrate 8 has an outer diameter A of 200 mm and a thickness B of about 1.2 mm.

A hole having an inner diameter C of about 40 mm is provided at the center of the disc.

The reinforcing member 9 is made of the same synthetic resin or metal as the substrate 8.

The reinforcing member 9 has a circular protrusion 9a in the center and a through hole 10 in the center.

The outer diameter of the circular protrusion 9a corresponds to the hole of the disc.

Then, the protrusion 9a of the reinforcing member 9 is fitted into the hole of the circular substrate.

The inner diameter D of the through hole 10 at the center of the reinforcing member 9 corresponds to the outer diameter of the protrusion 4c of the clamp member 4a shown in FIGS.

The reinforcing member 9 is held by the clamp members 4a and 4b shown in FIGS. The outer diameter E of the reinforcing member 9 corresponds to the outer diameter of the clamp members 4a and 4b, and is usually about 80 to 100 mm.

The thickness F of the reinforcing member 9 is preferably about the same as the thickness B of the circular substrate 8 from the viewpoint of mechanical strength. However, even if the thickness is about 0.5 times the thickness B of the circular substrate, it fully functions as a reinforcing member.

The height of the circular protrusion 9 a at the center of the reinforcing member 9 corresponds to the thickness B of the circular substrate 8.

The reinforcement member 9 and the circular substrate 8 can be fixed to each other by fitting the reinforcement member 9 into the central hole of the circular substrate 8 and then joining the same with an adhesive such as an epoxy resin. It can also be realized by an insert molding method in which the reinforcing member 9 is previously inserted into the mold for the circular substrate 8 and then injection molding is performed. When using the insert molding method, it is preferable to provide a plurality of protrusions 9b along the outer periphery of the reinforcing member 9, as shown in FIG. Due to the projection 9b, mechanical joining between the reinforcing member 9 and the circular substrate 8 can be obtained even if the materials have different properties.

When only the mechanical strength of the single-sided reproducing laser disc is to be reinforced, the use of an adapter cannot be avoided, but as shown in FIG. 7, a circular flat metal or synthetic resin is used in the center. It is also possible to provide the disc reinforcing member made of (4) by an insert molding method or fixing with an adhesive. Also in this case, when using the insert molding method, it is preferable to provide a plurality of protrusions 9b along the outer periphery of the reinforcing member 9 as shown in FIG.

Reinforcement of mechanical strength of the compact disc is also realized by providing a reinforcing member 9 made of a flat circular metal plate or a circular resin plate as shown in FIG. 7 by an insert molding method or fixing with an adhesive. be able to.

FIG. 8 shows another preferred embodiment of the present invention. In this embodiment, a circular substrate 11 having an outer shape A of 200 mm and a thickness B of about 1.2 mm has a stepped circular protrusion 12 having an outer diameter E of about 80 to 100 mm in the central clamp region. Then, the substrate for single-sided reproduction laser vision is molded so that it has a hole with an inner diameter C corresponding to the outer diameter of the protrusion of the clamp part in the center. That is, in this embodiment, the circular substrate for single-sided reproduction laser vision and the reinforcing member are integrally formed.

[0034]

[Effect of the device]

 On a circular substrate made of a polyolefin transparent resin with an outer diameter of 120 mm, a thickness of about 1.2 mm, and an inner diameter of a central hole of 15 mm, a circular substrate made of a polyolefin transparent resin with an outer diameter of 40 mm, a thickness of 1.2 mm, and a central hole of Bending strength was determined using a strength tester (Autograph IS-2000) manufactured by Shimadzu Corporation with and without bonding of a reinforcing member having an inner diameter of 15 mm with an epoxy adhesive. According to the test, the measured value when the reinforcing member was not provided was 7.4 (Kg), and the measured value when the reinforcing member was provided in the center was 15.1 (Kg). According to the test results, it was possible to obtain nearly twice the bending strength by joining the reinforcing members.

Thus, according to the present invention, an apparatus for a double-sided playback laser vision disc double-sided playback laser vision disc without increasing the inertia moment of the single-sided playback laser vision disc and without using an adapter. It is possible to increase the mechanical strength while allowing the use of

The compact disc according to the present invention can prevent the occurrence of cracks and the like due to the presence of the hole at the center.

[Brief description of drawings]

FIG. 1 is a sectional view of a double-sided reproduction laser vision disc.

FIG. 2 is a cross-sectional view of a double-sided reproduction laser vision disc held by a clamp.

FIG. 3 is a cross-sectional view of a single-sided reproducing laser vision disc according to the related art, which is held by using a clamp of a device for a double-sided reproducing laser vision disc.

FIG. 4 is a front view of a single-sided reproducing laser vision disc when a crack is formed around a center hole.

FIG. 5 is a cross-sectional view of an example of a single-sided reproduction laser vision disc according to the present invention.

FIG. 6 is a cross-sectional view taken along a plane perpendicular to the rotation axis, passing through the protruding portion 9a of the reinforcing member of the example of the single-sided reproduction laser vision disc according to the present invention.

FIG. 7 is a sectional view of another embodiment according to the present invention.

FIG. 8 is a sectional view of still another embodiment according to the present invention.

[Explanation of symbols]

 4a, 4b Clamping member 4c Clamping member protrusion 5 Single-sided playback laser vision disc 6 Adapter 7 Crack 8 Circular substrate 9 Reinforcing member 9a Reinforcing member protrusion 9b Reinforcing member protrusion 10 Hole 11 Circular substrate 12 Circular protrusion

Claims (4)

[Scope of utility model registration request] 1. A circular clamp area which is composed of one transparent disc-shaped substrate, has information recorded on one side and is covered with a light reflection film, and is clamped at the center of the disc by a clamp member. In addition, in a single-sided playback laser vision disc that has a hole with the same inner diameter as the outer diameter of the clamp protrusion in the center of the clamp region, make a hole with an inner diameter larger than the outer diameter of the clamp protrusion in the clamp region. , The material of the other area is made of the same material or different material, and by inserting and fixing the reinforcing member having the hole of the same inner diameter as the outer diameter of the protrusion of the clamp, only the above-mentioned clamp area is provided. A single-sided playback laser vision disc characterized by being formed thicker than the area. 2. A circular clamp area which is composed of a single transparent disc-shaped substrate, has information recorded on one side and is covered with a light-reflecting film, and is clamped at the center of the disc by a clamp member. In a single-sided reproduction laser vision disc having a hole with an inner diameter substantially the same as the outer diameter of the protrusion of the clamp in the center of the clamp area, by forming a thick part only in the clamp area in the process of making a disk-shaped substrate. A single-sided reproduction laser vision disc characterized in that only the clamp area is formed thicker than the other areas. 3. A circular clamp area which is composed of a single transparent disk-shaped substrate, has information recorded on one side and is covered with a light-reflecting film, and is clamped at the center of the disk by a clamp member. In a single-sided reproduction laser vision disc having a hole having an inner diameter substantially the same as the outer diameter of the protrusion of the clamp in the center of the clamp area, the disc reinforcing member made of a material different from the material of the other area is A single-sided playback laser vision disc characterized in that it is provided in the part. 4. A circular clamp area which is composed of a single transparent disk-shaped substrate, has information recorded on one side and is covered with a light-reflecting film, and is clamped at the center of the disk by a clamp member. In the compact disc having a hole having an inner diameter substantially the same as the outer diameter of the protrusion of the clamp in the center of the clamp area, a circular reinforcing member made of a material different from the material of other areas is provided in the clamp area. A compact disc that is characterized by being.