JP2001126378A - Turntable position adjustment mechanism for optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adjustment mechanism which can quickly adjust the turntable position of an optical disk device without stopping the revolution of an optical disk nor impairing the recording surface of the optical disk. SOLUTION: In this turntable position adjustment mechanism, the center axis of a turntable 3 is matched with the linear moving locus of optical axis of an objective lens 2 of an optical pickup. Then an adjustment shaft 6 is provided in its freely revolving way on the rotational center axis of a bracket 5 which holds a disk motor where the turntable 3 is fixed to its rotary shaft. Thus, the relative motions are regulated between the bracket 5 and the shaft 6 in their revolving directions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and more particularly to a means for aligning the center of an optical disk with a linear movement locus of an optical axis of an objective lens of an optical pickup.

[0002]

2. Description of the Related Art An optical disk apparatus rotates an optical disk clamped on a turntable, focuses laser light from an objective lens of an optical pickup on a spiral recording track of the optical disk in a spot shape, and reads a record from the reflected light. Tracking control for controlling the position of the objective lens is performed in order to align the main spot of the laser beam with the recording track, and there is a three-beam method as the method.

In the three-beam method, two sub-spots separated by a predetermined distance from a main spot are arranged so as to sandwich a recording track. A tracking error signal is obtained from this sub spot, but if the center of the optical disk, that is, the center of the turntable is not on the linear movement locus of the optical pickup objective lens, an offset occurs in the tracking error signal as the optical pickup objective lens moves. I will be.

Therefore, the position of the center of the turntable is adjusted while monitoring the tracking error signal. 5 and 6 show an example of a turntable position adjusting mechanism of a conventional optical disk device.

A turntable 3 shown in FIG. 1 is fixed to a rotating shaft of a disk motor. The disk motor is fixed to the bracket 8. Bracket 8 is chassis 4
Is rotatably supported around a shaft 4c.

As shown in detail in FIG. 6, a screw hole 4b is provided in a bent piece 4a of the chassis 4, and the screw hole 4b
A screw 9 is inserted through the elongated hole 8b of the bent piece 8a of the bracket 8. A compression coil spring 10 is fitted around the screw 9. By turning the screw 9, the bracket 8 rotates around the shaft 4 c and the position of the turntable 3 can be adjusted. Then, it is fixed at that position by the elastic force of the compression coil spring 10.

[0007]

In the conventional turntable position adjusting mechanism described above, the bent pieces 4a of the chassis 4
Since the adjustment portions such as the bent pieces 8a and the screws 9 of the bracket 8 are located directly below the optical disk, there is a possibility that the recording surface of the optical disk may be damaged if the operation is performed while the optical disk is rotated. Therefore, the rotation of the optical disk is stopped, the optical disk is removed, and the adjustment is performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide an optical disk which can be quickly adjusted without stopping the rotation of the optical disk and without damaging the recording surface of the optical disk. An object of the present invention is to provide a turntable position adjusting mechanism of the device.

[0009]

A turntable position adjusting mechanism for an optical disk apparatus according to the present invention is a turntable position adjusting mechanism for aligning a center axis of a turntable with a linear movement locus of an optical axis of an objective lens of an optical pickup. An adjustment shaft is rotatably provided on a rotation center axis of a bracket holding the disk motor to which the turntable is fixed, so as to restrict relative movement of the bracket and the adjustment shaft in a rotation direction. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A turntable position adjusting mechanism of an optical disk device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a turntable position adjusting mechanism of an optical disc apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view showing a main part of the turntable position adjusting mechanism, and FIG. FIG.

An optical pickup 1 shown in FIG. 1 has an objective lens 2 and is supported by a chassis 4 via a guide and a feed mechanism (not shown). Then, the optical pickup 1 is sent so that the objective lens 2 moves in the radial direction of the optical disc clamped to the turntable 3.

A turntable 3 shown in FIG. 1 is fixed to a rotating shaft of a disk motor. The disk motor is fixed to the bracket 5. 2 and 3, the bracket 5 is supported by the chassis 4 so as to be rotatable around the adjustment shaft 6.

The adjustment shaft 6 has a shape in which a projection 6d projects from the head provided with the adjustment groove 6a, and the outer periphery of the projection 6d forms a partial cylindrical surface 6c. The projection has three cutouts, and the cross section is substantially Y-shaped. And
The adjusting shaft 6 has a partial cylindrical surface 6c having a circular hole 4d of the chassis 4.
Is inserted so as to fit with the
Is inserted through a hole 5a having the same shape as the cross section of the convex portion 6d. The bracket 5 is locked by a retaining ring 7 fitted in the retaining ring groove 6b of the projection 6d.

By turning the adjusting shaft 6 by a driver inserted into the adjusting groove 6a, the bracket 5 rotates around the adjusting shaft 6 and the position of the turntable 3 can be adjusted. Although not shown, means for setting a frictional force between the chassis 4 and the bracket 5 is provided, and the bracket 5 is fixed at the adjusted position.

Since the adjustment by rotating the adjustment shaft 6 is performed from the back of the optical disk, the adjustment can be performed while the apparatus is set up and the optical disk is rotated. At this time, there is no risk of damaging the recording surface of the optical disk. FIG. 4A shows a tracking error signal before adjustment. While observing the tracking error signal, the position of the turntable 3 can be adjusted to have no offset as shown in FIG. 4B, and the adjustment can be performed easily and quickly.

Although the embodiment is constructed as described above, the invention is not limited to this. For example, the adjusting shaft 6 and the bracket 5
May be fitted in a non-circular cross section, and need not be limited to a Y-shaped cross section.

[0017]

According to the turntable position adjusting mechanism of the optical disk apparatus of the present invention, since the adjustment can be performed while rotating the optical disk, the position of the turntable can be adjusted easily and quickly. Moreover, there is no danger of damaging the optical disc during adjustment.

[Brief description of the drawings]

FIG. 1 is a plan view showing a turntable position adjusting mechanism of an optical disc device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the turntable position adjusting mechanism.

FIG. 3 is an exploded perspective view showing the main part.

FIG. 4 is a graph showing a comparison between a state adjusted by the turntable position adjusting mechanism and a tracking error signal when not adjusted.

FIG. 5 is a plan view showing an example of a turntable position adjusting mechanism of a conventional optical disc device.

FIG. 6 is a perspective view showing a main part of the turntable position adjusting mechanism.

[Explanation of symbols]

Reference Signs List 1 optical pickup 2 objective lens 3 turntable 4 chassis, 4a bent piece, 4b screw hole, 4c
Shaft, 4d hole 5 Bracket, 5a hole 6 Adjusting shaft, 6a Adjusting groove, 6b Retaining ring groove, 6c
Partial cylindrical surface 6d Convex part 7 Retaining ring 8 Bracket, 8a Folded piece, 8b Slot 9 Screw 10 Compression coil spring

Claims (1)

[Claims] In a turntable position adjusting mechanism for adjusting the center axis of a turntable to a linear movement locus of an optical axis of an objective lens of an optical pickup, a rotation center axis of a bracket holding a disk motor having a turntable fixed to a rotation axis. A turntable position adjusting mechanism for an optical disc device, wherein an adjusting shaft is rotatably provided on the optical disc device so as to restrict a relative movement of the bracket and the adjusting shaft in a rotating direction.