JPH0250347A - Disk clamping device - Google Patents

Abstract

PURPOSE:To obtain a thin type optical disk device and an inexpensive disk by providing a disk guide dish moved slidably up and down by a spring at a central axis part, and deciding the rotational center of an optical disk by the central hole of the optical disk. CONSTITUTION:The guide dish 4 moved slidably up and down by a coil spring 7 is provided at the central axis part, and a hub 1 is attracted by a magnet 3 by forming the inner diameter of the central hole of the hub 1 larger than that of the central hole of the optical disk 2. Therefore, the side end planes of the central hole of the optical disk 2 are abutted with the disk guide dish 4 simultaneously, thereby, the rotation center of the optical disk 2 is decided, and also, the height of the optical disk 2 can be decided by the disk guide dish 5. In such a way, it is possible to obtain the thin type optical disk device and the inexpensive disk 2.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a clamping device for an optical disk device.

(Prior Art) Conventionally, there have been two types of clamping devices for this type of optical disk device: a mechanical clamp type and a magnetic clamp type.

(1) Mechanical clamp method FIG. 4 shows the configuration of a conventional mechanical clamp method. In the figure, 8 is a coil holding plate, 9 is a disk holding plate, and the coil spring 1 for holding down the disk is
It can be slid up and down by 0. 11 is an optical disk, and 12 is a central hole.

At the same time as the disc pressing plate 9 presses down the optical disc 11, the disc guide plate 13 hits the inner surface of the disc central hole 12, thereby determining the rotation center of the optical disc 11, and the height of the optical disc 11 is determined by the disc receiving plate 14.

(2) Magnetic Clamp Method FIG. 5 shows the configuration of a conventional magnetic clamp method. In the figure, 15 is an optical disk, and 16
is a hub made of magnetic material. 17 is a magnetic coil that attracts the hub 16 and at the same time
8 and the hub center hole 19 determine the rotation center of the optical disc 15, and the disc receiving tray 2o determines the height of the optical disc 15.

(Problems to be Solved by the Invention) The conventional mechanical clamp method described above requires a clamping device above the optical disk, and has the disadvantage that the optical disk device cannot be made thin.

Also, with the conventional magnetic clamp method mentioned above.

It is necessary to bond the optical disk hub while aligning the optical disk rotation center and the center of the hub center hole with high precision, and the hole diameter of the hub center hole needs to be finished with high precision, which increases the cost of the hub itself. Moreover, the manufacturing process control for optical discs also has the drawback of increasing costs.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the conventional drawbacks and provide a thin optical disk device and an inexpensive disk.

(Means for Solving the Problems) A disk clamping device of the present invention includes an optical disk having a hub made of a magnetic material in the center, a central axis that determines the center of rotation of the optical disk, and a disk receiver for receiving the optical disk. In this clamping device having a magnet inside the disk tray, a disk guide tray is provided on the central shaft portion and can be slid up and down by a spring, and the rotation center of the optical disk is determined by the center hole of the optical disk itself.

(Function) With the above configuration, the present invention allows the optical disk device to be made thin by using the magnetic clamp method, and by determining the rotation center of the optical disk by the optical disk center hole, the hole diameter accuracy of the hub center hole can be reduced. This makes it possible to reduce the cost of the hub itself, and it is not necessary to align the center of the hub center hole with the center of the optical disk center hole with high precision, making it possible to supply inexpensive optical disks.

(Example) An example of the present invention will be described based on FIGS. 1 to 3.

FIG. 1 shows the configuration of a disc clamping device according to the present invention. In the figure, reference numeral 1 denotes a hub made of a ring-shaped magnetic material, which is adhered to an optical disk 2. As shown in FIG. The inner diameter of the center hole of the hub 1 is larger than the inner diameter of the center hole of the optical disc 2. 3 is a magnet, which attracts the hub 1 at the same time.
The center of rotation of the optical disc 2 is determined by the side end surface of the central hole of the optical disc 2 coming into contact with the disc guide plate 4, and the height of the optical disc 2 is determined by the disc receiving plate 5.

6 is a motor. According to this embodiment, a thin optical disk device can be provided by using the magnetic clamp method, and since the center of rotation of the optical disk is determined by the center hole of the optical disk 2, the hub 1 The accuracy of the inner diameter of the central hole can be lowered, and the cost of the hub 1 itself can be lowered. Furthermore, it is not necessary to align the center of the center hole of the hub 1 with the center of the center hole of the optical disk 2 with high precision, and an inexpensive optical disk can be supplied.

FIG. 2 is a sectional view of essential parts of the disc clamping device shown in FIG. 1. 7 is a coil spring.

FIG. 3 is a sectional view of a main part of a second embodiment of the present invention.

In the figure, an optical disc 2 is a single plate for single-sided recording and reproduction, and a hub 1 is bonded to the back side of the optical disc 2. Therefore, in this example.

The hub attraction force by the magnet 3 does not work in the direction of peeling off the hub 1, which increases the reliability of the adhesive surface between the hub 1 and the optical disk 2.

(Effects of the Invention) According to the present invention, by using a magnetic clamp system and providing a guide device that can be slid up and down by a coil spring on the central shaft portion, an optical disk device can be made thin and the center of rotation of the disk can be Since this is determined by the disk center hole, the accuracy of the hole diameter of the hub center hole can be lowered and the cost of the hub itself can be lowered.Furthermore, it is necessary to align the center of the disk center hole with the center of the hub center hole with high precision. Therefore, it is possible to supply inexpensive disks without any problems, and the practical effect is great.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a clamping mechanism of a disk clamping device according to a first embodiment of the present invention, FIG. 2 is a sectional view of a main part of the same mechanism, and FIG. Fig. 4 is a sectional view of the main parts of the disc clamping device, Fig. 4 is a sectional view of the main parts of the clamping device in the conventional mechanical clamp method, and Fig. 5 is a sectional view of the main parts of the clamping device in the same magnetic clamp method. be. DESCRIPTION OF SYMBOLS 1... Hub, 2... Optical disc, 3... Magnet, 4... Disc guide plate, 5... Disc saucer, 6... Motor, 7... Coil spring. Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 7 Coil spring diagram

Claims (1)

[Claims] an optical disk having a hub made of magnetic material in the center;
In the clamping device, the clamping device has a central axis that determines the center of rotation of the optical disk, a disk tray that receives the optical disk, and a magnet inside the disk tray, and a disk guide plate that is slidable up and down by a spring is provided on the central shaft portion. A disc clamping device characterized in that the optical disc is provided with a rotation center determined by a central hole of the disc itself.