JPH04281222A - Optical disk device - Google Patents

Abstract

PURPOSE:To improve the feeding accuracy by making the feeding pitch fine in an optical pickup transfer by a motor. CONSTITUTION:A band-shaped belt 6a for connecting the rotation axis of in a stepping motor 5 with a frame 8 for transferring an optical pickup 2 is wound round the shaft of the stepping motor 5 many times. The plane is moved for the frame 8 by the stepping motor 5. As for the movement of the optical pickup 2 on the rack base 8, the transferring distance for one step can be considerable reduced by selecting the diameter of the shaft of the stepping motor 5 by the revolution of the stepping motor.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc device having an optical pickup transfer device for reading information stored in an optical disc.

0002

2. Description of the Related Art In recent years, optical disk devices have been widely put into practical use as large-capacity memory devices, such as external memory devices for computers or digital audio devices. In particular, optical disk devices are characterized by excellent data access performance because the recording medium is in the form of a disk, and in order to fully utilize this feature as a drive device, various systems have been adopted for transporting devices for optical pickups.

FIG. 4 shows a schematic configuration diagram of a conventional example of an optical disk device, in which the constituent elements are 1 an optical disk, 2 an optical pickup, 3 a linear motor for transporting the optical pickup 2, and 4 its control circuit. It is. In order to access the optical pickup 2 to a desired track position on the optical disc 1, the linear motor 3 is controlled by a control circuit 4.
to transport the optical pickup 2. At this time, in order to transport the optical pickup 2, a stepping motor can be used instead of the linear motor 3 in order to reduce the size and cost. FIG. 3 shows a schematic configuration diagram of an optical pickup transfer device using a stepping motor. As shown in FIG. 3, the components include a stepping motor 5, and a belt-shaped connecting means 6, usually called an α belt, for connecting the stepping motor and the optical head.
7 is a pin for fixing the α belt 6 to the stepping motor 5, and 8 is a mount for transporting the optical pickup 2. As in the case of FIG. 4, the optical pickup 2 is transferred by rotating the stepping motor 5.

0004

[Problems to be Solved by the Invention] Generally, it is necessary to transport an optical pickup over a long distance at a minute pitch, but in the configuration shown in FIG.
Since the α belt 6 needs to be fixed, it cannot rotate more than one rotation, and the stepping motor 5 has a limit to miniaturizing the rotation angle by one step, so the feed pitch with one pulse input must be large to some extent. The problem is that you can't get it. For example, optical pickup 2
If the required transfer stroke is 30 mm and the feed angle of the stepping motor 5 is 15 degrees, the feed pulse per revolution is 24 pulses and the feed pitch of the optical pickup 2 is 1.25 mm, which is not the goal for higher precision. The track becomes inaccessible.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and provides an optical disc device capable of realizing a very small feeding pitch of an optical pickup.

[0006]

[Means for Solving the Problems] In order to achieve this object, the present invention uses a belt-like connecting means to connect the motor for moving the optical pickup and the optical pickup, and drives the motor from a control circuit. Accordingly, a band-shaped connecting means is wound around the rotating shaft of the motor, and the number of windings is changed by rotating the rotating shaft to transport the optical pickup.

[0007]

[Operation] In the optical disc device of the present invention having the above configuration, the band-like connecting means connecting the motor and the optical pickup is wound multiple times around the rotating shaft of the motor. , get caught up or sent out. By using a strip-shaped coupling means having a certain degree of rigidity, the winding or feeding of the strip-shaped coupling means wound around the rotating shaft of the motor described above is converted into plane movement along the guide of the optical pickup. Also,
Since the diameter of the winding around the rotating shaft changes depending on the number of turns, the moving distance of the optical pickup will gradually increase or decrease relative to the motor rotation speed. By correcting this with the control circuit, the stepping motor By selecting the diameter of the shaft, it is possible to considerably reduce the transport distance per step.

[0008]

Embodiments (Embodiment 1) Details of an optical disc device according to a first embodiment of the present invention will be explained with reference to the drawings. FIG. 1 shows a schematic configuration diagram of an optical pickup transfer device according to the present invention.
In place of the conventional α belt 6 in FIG. 3, a band-shaped belt 6a wound multiple times around the rotating shaft of the stepping motor 5 is used, but the other configuration is the same as that in the conventional FIG. 3. At this time, since the band-shaped belt 6a is wound multiple times around the rotating shaft of the stepping motor 5, the number of rotations is not limited. Therefore, by selecting the diameter of the shaft of the stepping motor 5, it is possible to ensure a sufficient transport stroke of the optical pickup 2 and to make the feed pitch per pulse sufficiently small. For example, similar to the example in FIG. 3, if the transport stroke of the optical pickup 2 is 30 mm, the feeding angle of the stepping motor 5 is 15 degrees, and the shaft diameter of the stepping motor 5 is 2 mm, the optical pickup 2 is fed with one pulse. The pitch is 0.26 mm, which is a value that allows highly accurate access control. As the optical pickup 2 is fed in one direction, the rotating shaft of the stepping motor 5 wraps around the band-shaped belt 6a, so the shaft becomes thicker, the feeding pitch gradually increases, and the number of tracks that can be accessed per pulse changes. By using a microcomputer in the control circuit and calculating the number of tracks to be accessed using the number of pulses, control is performed so that the influence of fluctuations in the feed pitch is eliminated.

(Embodiment 2) A second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a schematic configuration diagram of an optical disc device according to a second embodiment of the present invention. A V-shaped belt 6b is used instead of the band-shaped belt 6a in FIG. 1 of the first embodiment. This V-shaped belt 6b is wound around the shaft of the stepping motor 5 multiple times in the same manner as in FIG.
As in the case of FIG. 1, minute feeding of the optical pickup 2 is possible through multiple rotations, but unlike the case of FIG. Therefore, simpler access control than in the first embodiment is possible.

0010

[Effects of the Invention] As is clear from the above description, the present invention uses a band-like connecting means that can be wound multiple times to connect the rotating shaft of the motor and the optical pickup, so that the optical pickup transfer device can be easily constructed. With this configuration, highly accurate feeding can be realized, and it is possible to configure a small and low-cost optical disc device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an optical pickup transfer portion of an optical disc device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of an optical pickup transfer portion of an optical disc device according to a second embodiment of the present invention.

[Fig. 3] A perspective view of the optical pickup transport portion of a conventional optical disc device.

FIG. 4 is a side view showing the schematic arrangement of the main components of a conventional optical disc device.

[Explanation of symbols]

1 Optical disc 2 Optical pickup 5 Stepping motor 6a Band-shaped belt 6b V-shaped belt

Claims (3)

[Claims] 1. An optical disk storing information, an optical pickup for reading information stored on the optical disk, and a mount for transporting the optical pickup.
a belt-shaped connecting means connected to the pedestal for moving the pedestal, and a motor for driving the belt-shaped connecting means;
and a control circuit for driving the motor, wherein the band-shaped connecting means is connected to a rotating shaft of the motor and is wound, and the number of windings changes as the rotating shaft rotates. Device. 2. The optical disc device according to claim 1, wherein the band-shaped connecting means has a portion wound around the rotating shaft of the motor separated into two parts in a V-shape. 3. The optical disc device according to claim 1, wherein the control circuit controls the moving distance of the pedestal so that the number of rotations of the motor is proportional to the moving distance of the pedestal.