JPH09204744A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of vibration during the driving of an optical pickup by providing a contact part and an elastic engaging member in the optical pickup and making them in contact with each other so as to hold a lead screw. SOLUTION: A contact part 29a and an elastic engaging part 39 provided on one side of the pickup chassis 29 of an optical pickup 20 are made in contact with each other so as to hold a lead screw. Thus, a gap is formed with the lead screw 30 of the pickup chassis 29 whose other side is supported movably by a guide shaft 31 via a pair of bearings 42a and 42b. Thus, since the play of each component is eliminated at the time of driving the optical pickup 20 and any vibration is not caused, accuracy for supporting the optical pickup 20 is improved. Further, by forming a limiter in the periphery of the engaging part of the elastic engaging part extending in the axial direction of the lead screw 30, the engaging part is prevented from being disengaged when the lead screw 30 is rotated at a high speed.

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 for recording / reproducing information signals of an optical disc, and more particularly to an optical disc device having an improved optical pickup support structure.

[0002]

2. Description of the Related Art FIG. 9 is a perspective view showing an optical pickup of an optical disk device. As shown in the figure, in the optical pickup 1, a light flux L emitted from a light emitting element 2 such as a semiconductor laser passes through a diffraction grating 3 and a semi-transmissive reflective film 4, and is focused by an objective lens 5 on a signal surface of an optical disc (not shown). .

The return light flux L reflected on the signal surface of the optical disk is focused again on the photodetector 6 from the objective lens 5 through the semi-transmissive reflection film 4, and the photodetector 6 detects the signal of the optical disk. It has become so. When the optical disc rotates and the optical pickup 1 moves in the disc radial direction, the optical pickup 1 reads the signal train of the optical disc.

FIG. 5 is a plan view showing an example of a support structure for an optical pickup in a conventional optical disk device. As shown in the figure, the optical pickup 1 is fixed on a pickup chassis 7.
Is movably supported by one lead screw 8 and one guide shaft 9. The lead screw 8 and the guide shaft 9 are arranged in parallel on the chassis 10.

That is, both ends of the lead screw 8 are supported by bearings 11a and 11b fixed to the chassis 10, and the driving force of the motor 12 is transmitted to the lead screw 8 via the gear mechanism 13. An elastic meshing component 14 that meshes with the lead screw 8 as shown in FIGS. 6A and 6B is attached to one side of the pickup chassis 7. On both sides of this elastic meshing part 14,
As shown in FIG. 6C, bearings 15 a and 15 b formed integrally with the pickup chassis 7 support the lead screw 8.

On the other hand, both ends of the guide shaft 9 are attached to the chassis 1
It is fixed to 0. As shown in FIG. 6D, a U-shaped engaging portion 16 is integrally formed with the pickup chassis 7 on the other side portion of the pickup chassis 7.
The U-shaped engaging portion 16 engages so as to accommodate the guide shaft 9 therein, and thereby the height of one side of the optical pickup 1 is determined. A gap S is formed between the U-shaped engaging portion 16 and the guide shaft 9.

FIG. 7 is a plan view showing another example of the support structure of the optical pickup in the conventional optical disk device. As shown in the figure, the pickup chassis 7 to which the optical pickup 1 is fixed has one lead screw 8 and two lead screws 8 and 2.
It is movably supported by book guide shafts 9a and 9b. These lead screw 8 and guide shafts 9a, 9
b is arranged in parallel on the chassis 10, and the optical pickup 1 is arranged between the guide shafts 9a and 9b. The movement reference in the disk radial direction is the guide shaft 9a.

That is, the lead screw 8 has its both ends supported by bearings 11a and 11b fixed to the chassis 10 as in the case shown in FIG. 5, and the driving force of the motor 12 is transmitted via the gear mechanism 13. It is transmitted to the lead screw 8. On one side of the pickup chassis 7, FIG.
As shown in (a) and (b), a guide shaft 9a is housed in the base portion thereof, and an elastic meshing component 17 that engages with the lead screw 8 at the tip end portion thereof is attached. As shown in FIG. 8C, bearings 18a and 18b formed integrally with the pickup chassis 7 support the guide shaft 9a on both sides of the elastic meshing component 17.

Both ends of the guide shafts 9a and 9b are fixed to the chassis 10. Pickup chassis 7
As shown in FIG. 8D, a U-shaped engaging portion 16 is integrally formed with the pickup chassis 7 on the other side portion, and the U-shaped engaging portion 16 is formed in the same manner as described above. The portion 16 engages with the guide shaft 9b, which determines the height of the optical pickup 1 on one side.

[0010]

By the way, in the conventional optical pickup supporting structure in the optical disk device, since there is a gap S between the U-shaped engaging portion 16 and the guide shafts 9 and 9b, the optical There is a problem that vibration in the height direction occurs when the pickup 1 is driven.

Further, since the elastic meshing parts 14, 17 meshing with the lead screw 8 are not provided with a limiter, when the lead screw 8 is rotated at a high speed, the elastic meshing parts 14, 17 are inclined and the lead screw 8 is rotated. There is a problem that the optical pickup 1 is easily detached from the lead screw 8 because it easily crosses the groove.

Further, since the elastic meshing parts 14, 20 are only meshed on the lead screw 8, when the lead screw 8 is rotated at a high speed, the elastic meshing parts 14, 17 are formed.
However, there is a problem in that the focus is easily lifted and the focus servo is adversely affected.

Since the support structure shown in FIG. 7 is provided with two guide shafts 9a and 9b, the manufacturing cost for one guide shaft 9a is lower than that of the support structure shown in FIG. Will increase.

In order to solve the above-mentioned problems, the present invention does not generate vibration when the optical pickup is driven, so that even if the lead screw is rotated at a high speed, the optical pickup does not come off from this and the focus servo is not adversely affected. An object is to provide an optical disc device in which an optical pickup is supported.

[0015]

According to the present invention, the above object is to provide an optical disc apparatus having an optical pickup which is supported by a lead screw and a guide portion so as to be movable in the disc radial direction. ,
The present invention is achieved by an optical disk device including a contact portion that contacts an outer peripheral portion of the lead screw and an elastic meshing member that is provided so as to face the contact portion with the lead screw interposed therebetween and that meshes with the lead screw. It

According to the present invention, the lead screw is sandwiched by the contact portion and the elastic meshing portion provided in the optical pickup, and there is no gap between the optical pickup and the lead screw. There is. And,
This optical pickup is movably supported by the guide shaft via a bearing. Therefore, when the optical pickup is driven, there is no backlash and no vibration occurs.

[0017]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Since the embodiments described below are suitable examples of the present invention, various technically preferable limitations are attached, but the scope of the present invention particularly limits the present invention in the following description. Unless stated otherwise, the present invention is not limited to these embodiments.

The optical disk device according to the embodiment of the present invention is used, for example, to reproduce information or a signal recorded on the optical disk, or to record and reproduce a signal or information on the optical disk.

An optical pickup as shown in FIG. 4 is mounted on this optical disk device. As shown
The optical system 21 of the optical pickup 20 includes the following optical elements. That is, the light flux L emitted from the light emitting element 22 such as a semiconductor laser is reflected by the semi-transmissive reflection film 24 via the diffraction grating 23, and the objective lens 25.
It is designed to be focused on the signal surface of an optical disk (not shown).

Then, the return light flux L reflected by the signal surface of the optical disk is focused on the photodetector 26 from the objective lens 25 through the semi-transmissive reflection film 24. Thereby, the signal on the signal surface of the optical disk can be reproduced, for example.

A part of the light emitting element 22, which is each optical component of the optical system 21, the diffraction grating 23, the photodetector 26,
The semi-transmissive reflective film 24 is attached to the pickup chassis 29.
It is housed in the housing portion 27 of

FIG. 1 is a plan view showing an embodiment of an optical disk device according to the present invention, which is characterized by the support structure of the optical pickup 20. As shown in the figure, the optical pickup 20 is integrally fixed on a pickup chassis 29 having a generally L-shaped planar shape. The pickup chassis 29 is movably supported by one lead screw 30 and one guide shaft 31.

These lead screw 30 and guide shaft 3
1 are arranged in parallel on the chassis 32, and the movement reference in the disk radial direction is the guide shaft 31. In the present embodiment, the pickup chassis 2
Although the planar shape of 9 is formed to have an L-shape as a whole, the shape is not limited to this and may be formed to have a T-shape.

One end of the lead screw 30 is supported by a pivot bearing 33 fixed to the chassis 32. On the other hand, the other end of the lead screw 30 is supported by a bearing 34 fixed to the chassis 32, and the other end is biased by a leaf spring 35 fixed to the chassis 32. Therefore, both ends of the lead screw 30 are formed in a conical shape.

A driven gear 36 is fixed near the other end of the lead screw 30, and the driven gear 36 is a driving gear 38 fixed to a drive shaft 37a of a DC motor 37.
Is engaged. That is, the driving force of the DC motor 37 is transmitted to the lead screw 30 via the driving gear 38 and the driven gear 36.

On one side of the pickup chassis 29,
As shown in FIGS. 2A and 2B, a contact portion 29a that contacts the outer peripheral portion of the lead screw 30 is formed so as to project laterally in a plate shape. An elastic meshing member 39 is fixed to one side of the pickup chassis 29 by a mounting screw 40 so as to face the contact portion 29a with the lead screw 30 interposed therebetween. A meshing portion 39a that meshes with the lead screw 30 is formed at the tip of the elastic meshing member 39. The meshing portion 39a meshes with the lead screw 30 so that the lead screw 3
When 0 is rotated, the optical pickup 20 moves in the disc radial direction via the elastic meshing member 39 and the pickup chassis 29. The lead screw 30 also serves as a reference in the height direction of one side of the pickup chassis 29.

As shown in FIG. 3, a plate-like limiter 39b is formed around the meshing portion 39a of the elastic meshing member 39 so as to project in the axial direction of the lead screw 30. Since the limiter 39b projects around the engagement portion 39a, when the engagement portion 39a is inclined, the limiter 39b comes into contact with the outer peripheral portion of the lead screw 30. In the present embodiment, the meshing portion 39
Although the a and the limiter 39b are integrally formed, the present invention is not limited to this, and they may be formed separately and the meshing portion 39a may be fixed on the limiter 39b.

Further, as shown in FIGS. 2 (c) and 3,
Near the contact portion 29a of the pickup chassis 29, stoppers 41a and 41b are provided with a predetermined gap b from the outer peripheral portion of the lead screw 30. These stoppers 41a and 41b are integrally formed with the elastic meshing member 39, and stand up in an inverted L shape so as to give elastic force to both sides of the limiter 39b. As shown in FIG. 2B, this predetermined gap b is defined by the elastic meshing member 39.
It is set to be smaller than the meshing amount a of the meshing portion 39a of the above and the lead screw 30. By setting in this way, even if the lead screw 30 is rotated at a high speed and the meshing portion 39a of the elastic meshing member 39 begins to float, the elastic force of the stoppers 41a and 41b on the opposite side causes the original positional relationship. Since it returns, the meshing portion 39a does not come off.

Further, the base portion 39c of the elastic meshing member 39 is formed thinner than the thickness of the limiter 39b, so that the elastic meshing member 39 is given elasticity. Due to this elasticity, the contact portion 29 of the pickup chassis 29
a, the meshing portion 39a of the elastic meshing member 39, and the lead screw 30 are kept in contact with each other. Therefore, the contact portion 29a, the meshing portion 39a, the lead screw 30
Means that a good contact state with no rattling is always maintained.

On the other hand, both ends of the guide shaft 31 are fixed to the chassis 32 with an accuracy required to serve as a movement reference in the disk radial direction. The guide shaft 31 also serves as a reference in the height direction of the other side portion of the pickup chassis 29. The other side of the pickup chassis 29 is shown in FIG.
As shown in (d), the box-shaped engaging portion 2 having an opening at the bottom.
9b is formed integrally with the pickup chassis 29. Bearings 4 are provided at both ends of the box-shaped engaging portion 29b.
2a, 42b are fixed, and these bearings 42a, 4b
The guide shaft 31 is inserted through 2b. These bearings 4
For the 2a and 42b, for example, oil-impregnated bearing equivalent products are adopted.

In the optical disk device according to the embodiment of the present invention, the distance between the bearings 42a and 42b is L1, the axial distance between the guide shaft 31 and the lead screw 30 is L2, and the dynamic friction between the guide shaft 31 and the bearings 42a and 42b. When the coefficient is μ, the L-shape of the pickup chassis 29 is set so that the relationship of 1 <2 · μ · L2 / L1 is established. That is, if the value of L2 is too large,
Since the optical pickup 20 cannot move and cannot function as an optical disk device, it is necessary to reduce the value of L2 to some extent. As described above, the shape of the pickup chassis 29 is not limited to the L shape as long as each side satisfies the above relationship.

Thus, in the optical disk device of this embodiment, when the lead screw 30 is driven by the motor 37, the optical pickup 20 moves in the disk radial direction with the guide shaft 31 as the movement reference. At that time, the lead screw 30 serves as a reference in the height direction of one side portion of the pickup chassis 29, and the guide shaft 31 serves as a reference in the height direction of the other side portion of the pickup chassis 29.

The contact portion 29a and the elastic meshing member 3 are provided on one side of the pickup chassis 29 of the optical pickup 20.
9 is provided, and the contact portion 29a and the meshing portion 39a of the elastic meshing member 39 are in contact with each other so as to sandwich the lead screw 30. That is, no gap is formed between the lead screw 30 and the contact portion 29a and the meshing portion 39a. Moreover, the other side portion of the pickup chassis 29 of the optical pickup 20 is connected to the guide shaft 3 via a pair of bearings 42a and 42b.
1 is movably supported. Therefore, when the optical pickup 20 is driven, there is no rattling of each component and vibration does not occur, so that the accuracy of supporting the optical pickup 20 is good.

Further, the meshing portion 39 of the elastic meshing member 39.
A plate-like limiter 39b is formed around a,
The limiter 39b is formed so as to project in the axial direction of the lead screw 30. Therefore, when the lead screw 30 is rotated at a high speed, the limiter 39b contacts the outer peripheral portion of the lead screw 30 even if the mesh portion 39a inclines and goes over the groove of the lead screw 30, so that the mesh portion 39a leads to the lead portion. It does not come off from the screw 30.

Further, stoppers 41a and 41b are provided near the contact portion 29a with a predetermined gap b from the outer peripheral portion of the lead screw 30. Therefore, even if the lead screw 30 is rotated at a high speed and the meshing portion 39a of the elastic meshing member 39 starts to float, the elastic force of the stoppers 41a and 41b on the opposite side restores the original positional relationship, and thus the meshing portion 39a. Does not come off and does not adversely affect the focus servo.

Although the above embodiment has been described by using the optical pickup for mini-disc as an example, the present invention is not limited to this, and it is obvious that an optical pickup for other optical discs can be applied to the present invention. Is.

[0037]

As described above, according to the optical disk device of the present invention, vibration does not occur when the optical pickup is driven, and even if the lead screw is rotated at a high speed, the optical pickup may come off from the optical pickup or adversely affect the focus servo. The optical pickup is supported so as not to give.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of an optical disk device according to the present invention.

FIG. 2 is a detailed view of each part of FIG. 1, where (a) is a view taken along the line I-I, (b) is a view taken along the arrow J, and (c) is a view taken along the line KK. d) is a view taken along the line MM.

FIG. 3 is a perspective view showing a main part of an elastic meshing member according to the present embodiment.

FIG. 4 is a perspective view showing an optical system of an optical pickup in the optical disc device according to the present invention.

FIG. 5 is a plan view showing an example of a support structure of an optical pickup in a conventional optical disc device.

6A and 6B show in detail each part of FIG. 5, where FIG. 6A is a view taken along the line AA, FIG. 6B is a view taken along the line B, and FIG. d) is a DD line arrow view.

FIG. 7 is a plan view showing another example of a support structure for an optical pickup in a conventional optical disc device.

FIG. 8 is a detailed view of each part of FIG. 7, where (a) is a view taken along the line EE, (b) is a view taken along the arrow F, and (c) is a view taken along the line GG. d) is a H-H line arrow view.

FIG. 9 is a perspective view showing an optical system of an optical pickup in a conventional optical disc device.

[Explanation of symbols]

20 Optical Pickup 21 Optical System 22 Light Emitting Element 23 Diffraction Grating 24 Semi-Transmissive Reflective Film 25 Objective Lens 26 Photodetector 27 Housing L Luminous Flux 29 Pickup Chassis 29a Contact 30 Lead Screw 31 Guide Axis 32 Chassis 33 Pivot Bearing 34 Bearing 35 Plate Spring 36 Driven gear 37 Motor 37a Drive shaft 38 Main drive gear 39 Elastic meshing member 39a Meshing part 39b Limiter 39c Base 40 Mounting screws 41a, 41b Stopper b Predetermined gap a Meshing amount L1 Bearing distance L2 Between guide shaft and lead screw Distance between axes

Claims (9)

[Claims] 1. An optical disc apparatus comprising an optical pickup supported by a lead screw and a guide portion so as to be movable in the disc radial direction, wherein the optical pickup has a contact portion that comes into contact with an outer peripheral portion of the lead screw. An optical disk device comprising: an elastic meshing member that is provided so as to face the contact portion across the lead screw and that meshes with the lead screw. 2. The optical disk device according to claim 1, wherein a limiter is formed around the meshing portion of the elastic meshing portion so as to project in the axial direction of the lead screw. 3. The optical disk device according to claim 1, wherein a stopper is provided in the vicinity of the contact portion with a predetermined gap from the outer peripheral portion of the lead screw. 4. The optical disk device according to claim 2, wherein a stopper is provided in the vicinity of the contact portion with a predetermined gap from the outer peripheral portion of the lead screw. 5. The optical disk device according to claim 3, wherein the predetermined gap is set to be smaller than the amount of meshing between the meshing portion of the elastic meshing portion and the lead screw. 6. The optical disk device according to claim 4, wherein the predetermined gap is set to be smaller than a meshing amount between the meshing portion of the elastic meshing portion and the lead screw. 7. The optical disk device according to claim 3, wherein the stopper is formed integrally with the elastic meshing portion. 8. The optical disk device according to claim 4, wherein the stopper is formed integrally with the elastic meshing portion. 9. The optical pickup is movably supported by the guide shaft via a pair of bearings, a gap L1 between the bearings, an axial distance L2 between the guide shaft and the lead screw, and the guide. The optical disk device according to claim 1, wherein a relationship of 1 <2 · μ · L2 / L1 is established between a dynamic friction coefficient μ of the shaft and the bearing.