JPS63187482A - optical disc - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical disc on which information can be recorded and reproduced optically, and more particularly to an optical disc with a hub suitable for clamping the optical disc.

[Conventional technology]

Conventional optical disc binding [includes playback-only optical video case files (VD), compact discs (CN), and
There is a recordable and reproducible original disc (DRAr). When installing these optical discs in a recording/playback device or a playback device (hereinafter referred to as a drive), Japanese Patent Application Laid-Open No. 54-151
404, 1 "Introduction to CN Player" P. 114, Corona Publishing, provided in the drive,
The optical disc was held by mechanically clamping an inner circle formed on the optical disc to a disc positioning turntable. Hereinafter, the above holding mechanism will be referred to as a mechanical clamp.

On the other hand, as shown in FIG.
n-pAht), a configuration in which an optical disk is housed in a cartridge, similar to a floppy disk for magnetic recording, has been considered, simplifying the drive structure,
In addition, with the aim of saving space, a shift from the above-mentioned mechanical clamp to a Magret f-yak type clamp is being considered.

Conventionally, when using such a magnetic chuck type clamp, it is necessary to bond a magnetic material to a non-magnetic material, for example, a disk carrier such as a plastic such as PMMA or PC, or a glass plate. There were problems that needed to be resolved in terms of performance, disc optical properties, productivity, etc.

[Problem that the invention seeks to solve]

Conventionally, when joining an optical disk carrier, there is no suitable guide for alignment, that is, alignment between the signal track of the optical disk and the inner diameter of the knob, resulting in poor productivity.

An object of the present invention is to increase the productivity of optical discs.

Another purpose is to increase the bonding strength between the hub and the optical disk.

[Means for solving problems]

The above purpose is to improve the alignment accuracy by insert molding the magnetic material with thermoplastic resin and simultaneously forming a circumferential rib along the inner circle formed on the disk carrier. I can do it.

That is, a ribbed hub having a magnetic material can be placed on the inner circle of the disk carrier and then bonded.

[Effect]

Thermoplastic resin (hub) with magnetic material inserted at ℃
By forming the optical disk carrier from the same material as the optical disk carrier, it is possible to diversify the bonding methods. That is, a so-called adhesive may be used, and since the solubility coefficients are the same, dissolution bonding using an organic solvent may also be used, and bonding methods such as ultrasonic welding and spin welding may be used.

Furthermore, the ribs formed on the hub function as positioning during bonding, and it is also possible to bond at the ends of the ribs disposed to each other, making it possible to further increase the optical disk bonding strength.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained using one drawing. FIGS. 1 and 2 are diagrams used to explain one embodiment of the present invention, and 1 shows a record capable of recording optical information on an injection-molded polycarbonate replica (thickness t2). forming a membrane, such as a chalcogenide compound (approximately 1ooo;
) L, after formation of protective membrane.

After adhesive bonding 5 (not shown), the optical disc can be used on both sides. 2 is a ribbed hub in which a magnetic body 6 is insert-molded with polycarbonate 7. 5 is a cartridge, and 4 is a turntable equipped with a magnet, which magnetically chucks the magnetic body 2 and positions the disk.

In FIG. 2, the rib 8 of the hub is aligned with the inner circle of the optical disc and bonded with adhesive.

By doing so, it becomes easy to align the signal track on the disk with the center hole of the hub. 9 is a protrusion used for welding.

Fig. 3 shows a hub 7 with a welding protrusion 9 on the bottom surface, and ultrasonic welding or spin welding is possible. Fig. 4 shows another embodiment, in which the ribs 8 of the hub 7 are used. By using a welding rib 9 on the bottom surface, it became possible to join the hubs together, and the reliability of disk joining was improved.

FIG. 5 is a diagram showing another embodiment. That is, plastic molding is performed so as to cover the entire back surface of the magnetic body 6, thereby improving alignment accuracy and reinforcing the magnetic body. Here, the bonding with the plastic material can be increased by applying a plastic finish to the back surface of the magnetic material or chemically etching it.

FIG. 6 shows another embodiment in which the center hole 10, which is the center of disk rotation, is made of polycarbonate. With this structure, the drive side shaft (
(not shown).

FIG. 7 is a diagram showing another embodiment of the present invention, in which a plastic film 11 with an adhesive is bonded to the surface of the magnetic body 3. With this configuration, the distance between the magnet (not shown) attached to the turntable and the magnetic body is kept constant.

Control of magnetizing force becomes easier. Instead of the plastic film, other non-magnetic materials may be used here, such as insert-molded plastics and, for example, coatings.

FIG. 8 is a diagram showing another embodiment of the present invention. That is, as is often used in ICs and LSIs, the magnetic bodies 6 are pressed into the shape of a lead frame, and after insert molding a large number of pieces at the same time, the outer periphery is finished as shown in FIG. By doing so, a large number of rings with magnetic material can be molded at the same time, and costs can be reduced.

FIG. 10 is a diagram showing another embodiment of the present invention. That is, the optical disc to which the present invention is applied is mounted in a cartridge, and the history of the disc manufacturing process cannot be easily identified. For this reason, the disk manufacturing history is printed on the plastic surface with magnetic inserts, or
It is stamped during molding. In this way, the manufacturing history of the optical disk can be confirmed without disassembling the cartridge.

〔Effect of the invention〕

According to the present invention, since the rib for positioning is attached to the hub, it is possible to obtain an original disk with high positioning accuracy during automatic joining and high joining strength.

[Brief explanation of the drawing]

FIG. 1 shows an optical disc according to an embodiment of the present invention. FIG. 2, FIG. 3, FIG. 4, FIG. 5, and FIG. 6 are sectional views showing the overall structure of the player and cartridge. FIG. 7, FIG. 8, FIG. 9, and FIG. 10 are sectional views of a hub portion showing an example and an embodiment of the present invention, respectively. 1・・・・・・・・・−・・Optical disc 2・・・・・・・・−・・Hub 3・・・・・・・・・・・・・Cartridge 4・・・・・・・・・・
...Turntable with magnet 2 Figure 55 Illustration U Art Figure a

Claims (1)

[Claims] 1. In a double-sided bonded optical disc, a plastic hub made of a magnetic insert is fitted, the hub having a rib positioned along the already formed inner circle of the disc;
An optical disc characterized by being made by joining. 2. An optical disc according to claim 1, characterized in that the tip of the rib to be positioned is joined to the tip of the rib that is similarly positioned from another surface.