JP2000156054A - Optical pickup feed mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the mechanism without increasing drive load due to friction force on a central part of an optical pickup moving range, without causing any tooth skip and without causing any mechanism fault due to that the optical pickup is forcedly fed on the end part of the moving range. SOLUTION: In this optical pickup feed mechanism for fixing leaf springs 8, 8a to an optical pickup, engaging a rack energized by the leaf spring 8 with a lead screw 6 and feeding the optical pickup by rotating the lead screw 6, a limiter 5a for limiting a displacement amount in the direction that the rack 9 is away from the lead screw 6 to the amount corresponding to the position of the optical pickup is arranged oppositely to the leaf spring 8a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk reproducing apparatus, and more particularly to an optical pickup feed mechanism.

[0002]

2. Description of the Related Art An example of a conventional optical pickup feeding mechanism of an optical disk reproducing apparatus will be described with reference to FIG. The optical pickup 2 shown in the figure is supported by an optical pickup guide shaft 7 so as to be movable in the radial direction of an optical disk (not shown). The lead screw holders 5, 5 are fastened to a base chassis (not shown) to support the optical pickup guide shaft 7, and further to rotatably support the lead screw 6.

A leaf spring 8 is fastened to the optical pickup 2 by screws 10 and 10 and urges a rack 9 attached to the optical pickup 2 so as to press the rack 9 against the lead screw 6. The rack 9 is kept engaged with the lead screw 6 by the elastic force of the leaf spring 8, and the optical pickup 2 is fed in the disk radial direction by rotating the lead screw 6 by an optical pickup feed motor (not shown).

[0004]

In the conventional optical pickup feed mechanism described above, the urging force of the rack is the same at both ends of the moving range where the movement of the optical pickup is restricted and at the center of the moving range. Was difficult to set.
In other words, if the biasing force is too weak, careless tooth skipping will occur,
On the other hand, if the urging force is too strong, the driving load increases due to the frictional force, and further, there is a fear that the forcible feeding is performed at the end of the moving range, which may cause a failure of the mechanism.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to prevent a driving load from increasing due to frictional force in a predetermined portion of a moving range and to cause tooth jump. Another object of the present invention is to provide an optical pickup feed mechanism in which the feed is not forcibly performed in another part of the moving range and does not cause a failure of the mechanism.

[0006]

According to the present invention, there is provided an optical pickup feed mechanism in which a leaf spring is fixed to an optical pickup, a rack biased by the leaf spring is engaged with a lead screw, and a light is transmitted by rotation of the lead screw. In an optical pickup feed mechanism for feeding a pickup, a limiter is disposed to limit a displacement amount in a direction in which the rack is disengaged from a lead screw to an amount corresponding to a position of the optical pickup in opposition to the leaf spring.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical pickup feed mechanism of an optical disk reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings. 1 to 3 show an optical pickup feed mechanism of the embodiment. Reference numeral 1 shown in FIG. 1 is a base chassis that supports the optical disk reproducing unit.

The optical pickup 2 has an objective lens 2a, and is guided by an optical pickup guide shaft 7 so that the objective lens 2a is fed in the radial direction of the disk clamped on the disk turntable 3.

The optical pickup feed motor 4 shown in FIGS. 1 to 3 is fastened to a lead screw holder 5, and the lead screw holder 5 is fastened to the base chassis 1. The lead screw holder 5 rotatably supports a lead screw 6 driven to rotate by the optical pickup feed motor 4.

The leaf spring 8 is fastened to the optical pickup 2 by screws 10 and 10 and a rack 9 attached to the leaf spring 8.
Is pressed so as to be pressed against the lead screw 6. The rack 9 is kept engaged with the lead screw 6 by the elastic force of the leaf spring 8, and the optical pickup 2 is sent by rotating the lead screw 6 by the optical pickup feed motor 4.

The distal end of the leaf spring 8 is bent in a crank shape, and the bent portion 8 a passes through an elongated hole provided in the lead screw holder 5. As shown in detail in FIG.
The upper end of the elongated hole of the lead screw holder 5 is formed in a cam shape, and constitutes a limiter 5a.

The central portion of the limiter 5a is low and close to the bent portion 8a of the leaf spring 8, and both ends of the limiter 5a are high and separated from the bent portion 8a of the leaf spring 8. By providing such a limiter 5a, the displacement amount of the rack 9 is restricted when the optical pickup 2 is fed in the center portion, and the rack 9 is prevented from jumping. When both ends are fed, excessive feeding is performed to prevent the mechanism from malfunctioning. Moreover, in the normal feeding operation, the driving load does not increase because the frictional force is too large.

As described above, according to the optical pickup feed mechanism of the present embodiment, there is no increase in driving load due to frictional force in the central portion of the optical pickup moving range, and further, no tooth jump occurs, No overfeeding will occur at the end of the range and cause a mechanism failure. In addition, it is only necessary to provide a long hole in the conventional member, and the cost does not increase.

Although the embodiment is constructed as described above, the invention is not limited to this. For example, the limiter 5a may be formed in a member different from the lead screw holder 5. Further, the leaf spring and the rack may be integrally formed, and the rack 9
May be urged in a direction other than the chassis surface direction. Further, the lead screw 6 may be driven via a gear.

[0015]

According to the optical pickup feeding mechanism of the present invention, there is no increase in driving load due to frictional force in a predetermined portion of the optical pickup moving range, and no tooth jump occurs. There is no possibility that excessive feeding is performed in other parts to cause a mechanism failure.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of an optical pickup feed mechanism according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a part of the optical pickup feeding mechanism.

FIG. 3 is a perspective view showing a part of the optical pickup feeding mechanism.

FIG. 4 is a perspective view showing an example of a conventional optical pickup feed mechanism.

[Explanation of symbols]

 Reference Signs List 1 base chassis 2 optical pickup, 2a objective lens 3 disk turntable 4 optical pickup feed motor 5 lead screw holder, 5a limiter 6 lead screw 7 optical pickup guide shaft 8 leaf spring, 8a bent portion 9 rack 10 screw

Claims (1)

[Claims] An optical pickup feeding mechanism for fixing a leaf spring to an optical pickup, meshing a rack urged by the leaf spring with a lead screw, and feeding the optical pickup by rotation of the lead screw. An optical pickup feed mechanism, comprising a limiter for limiting a displacement amount in a direction in which the rack is disengaged from the lead screw to an amount corresponding to a position of the optical pickup.