JPH11328885A - Feed mechanism for optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize smooth movement of an optical pickup by keeping an engaging state of the both appropriately by operating tilt adjusting function even if an optical pickup is tilted to a lead screw. SOLUTION: This mechanism is a feed mechanism for an optical pickup 2 moving an optical pickup 2 to the prescribed direction by rotating a lead screw 4 by a rotation driving means 13. This mechanism is provided with a base member 20, two guide rails 1, 3 attached to a base member in parallel with it, an optical pickup 2 guided and moved by these rails, a lead screw 4 extended in parallel with the guide rails and constituted rotatably in the direction of an axis, a rotation driving means 13 rotation-driving the lead screw, and connecting section 15 of the optical pickup and the lead screw. Further, the connecting section 15 is provided with a teeth receiving part 5 fixed to the optical pickup 2, a teeth 6 one end of which is engaged with the teeth receiving part 5 rotatably and the other end is engaged with the lead screw 4, and energizing means 8, 9 of the lead screw holding the other end of the teeth 6 so that the teeth is in parallel with the lead screw.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed mechanism for an optical pickup, and more particularly, to a feed mechanism for an optical pickup capable of suitably maintaining an engagement state between an optical pickup and a lead screw even when a tilt adjusting function is operated. About.

[0002]

2. Description of the Related Art A feed mechanism of an optical pickup used for recording information on an information recording medium and reproducing information from the information recording medium generally includes a base member (20) and a guide attached to the base member. A rail (1, 3); an optical pickup (2) held on the guide rail and movable in the same direction as the guide rail extends; and an optical pickup (2) extending parallel to the guide rail and rotating in its axial direction. Lead screw (4) attached to the base member as possible
And a feed motor (1) for rotating this lead screw.
3), optical pickup (2) and lead screw (4)
And a connecting part (15) for connecting the optical pickup to the optical pickup by driving a feed motor and rotating a lead screw to move the optical pickup in a direction crossing a track on an information recording medium (for example, an optical disk). It is configured to record or reproduce information (see FIG. 1).

FIG. 10A is a cross-sectional view showing a structure of a connecting portion between an optical pickup and a lead screw in such a conventional optical pickup feed mechanism. FIG.
As shown in (a), the optical pickup 42 and the lead screw 44 are connected via a tooth 46, and the tooth 46 transmits the rotation of the lead screw 44 to move the optical pickup 42 along the guide rail 43 (on the paper). (In the direction perpendicular to). The teeth 46 are fixed to the optical pickup 42 by screws 45. A leaf spring 47 for holding the teeth is provided between the tooth 4 and the screw 45, and the leaf spring 47 urges the tooth 46 toward the lead screw 44 (downward in FIG. 10), so that the tooth 46 is The lead screw 44 is configured so as not to come off from the thread.

[0004]

In recent years, there has been a demand for recording / reproducing with high-density signals with the increase in capacity of optical disk devices. Under such demands, if there is a tilt error between the optical disk surface and the optical axis of the laser light condensed by the condenser lens, it may be difficult to record and reproduce signals at high density. For this reason, the optical disk device is usually configured so that such a tilt error can be corrected by moving the guide rail up and down. When the tilt error is corrected, the guide rail 43 of the optical pickup and the lead screw 44 are inclined. In this case, the teeth 46 connecting the optical pickup 42 and the lead screw 44 are fixed to the optical pickup 42 in the conventional connection mechanism between the optical pickup and the lead screw shown in FIG. As shown in FIG. 10B, the teeth 46 are inclined with respect to the lead screw 44. When the optical pickup 42 moves along the guide rail 43 in this state, the teeth 46 are disengaged from the lead screw 44 due to the inclination of the guide rail 43 and the lead screw 44, and the load on the motor that rotates the lead screw 44 varies. In some cases, smooth recording / reproduction on the optical disc cannot be performed.

In view of such a problem, the feed mechanism of the optical pickup according to the present invention always keeps the engagement state between the teeth and the lead screw in parallel even when the error is corrected when the guide rail is moved up and down. An object of the present invention is to provide an optical pickup feed mechanism that can maintain the optical pickup.

[0006]

In order to solve the above-mentioned problems, a feed mechanism for an optical pickup according to the present invention comprises a base member (20) and two guide rails (1) attached to the base member in parallel with each other. , 3), an optical pickup (20) that moves while being guided by the guide rail, a lead screw (4) that extends in parallel with the guide rail, and is configured to be rotatable in the axial direction thereof, and the lead. The optical pickup comprises: a rotation driving means (13) for driving a screw to rotate; and a connecting portion (15) for connecting the optical pickup and the lead screw. The optical pickup is rotated by rotating the lead screw by the rotation driving means. In a feed mechanism of an optical pickup for moving the optical pickup in a predetermined direction, the connecting portion is connected to a teeth receiving portion ( ), A tooth (6) having one end rotatably engaged with the tooth receiving portion and the other end engaged with the lead screw, and the other end of the tooth being parallel to the tooth and the lead screw. And biasing means (8, 9) for biasing the lead screw so as to maintain the pressure.

As described above, in the feed mechanism of the optical pickup according to the present invention, the teeth interposed between the optical pickup and the lead screw are connected to the teeth receiving portion (optical pickup) at the connection between the optical pickup and the lead screw.
And a biasing means for biasing the teeth so as to keep the teeth parallel to the lead screw. , That is, even if an inclination occurs between the optical pick-up and the guide rail,
The teeth can always be kept parallel to the lead screw. Accordingly, load fluctuations on the feed motor caused by the teeth being disengaged from the lead screw or the teeth being pressed in an inclined state with respect to the lead screw are reduced, so that information can be recorded / reproduced smoothly. .

The teeth and the teeth receiving portion are formed of a spherical projection and a spherical seat corresponding to the shape of the projection, so that the teeth and the teeth receiving portion are formed in two.
It can be pivoted in the axial direction. Here, it is preferable to further provide stopper means for restricting the movement of the teeth in the moving direction of the optical pickup.

The engaging portion between the teeth and the teeth receiving portion is
The teeth and the teeth receiving portion can be rotated in one axial direction by comprising a semi-cylindrical projection and a semi-cylindrical seat corresponding to the shape of the projection.

In this case, the movement of the teeth can be made in the moving direction of the optical pickup or perpendicular to the moving direction of the optical pickup without providing stopper means depending on the directions of the semi-cylindrical projection and the semi-cylindrical seat. Can be restricted in the direction in which Therefore, this configuration can be suitably used for an optical pickup device that performs tilt correction only in one axis direction.

Further, the urging means for urging the teeth to the lead screw includes a first magnet provided at the end of the tooth on the lead screw side, and a first magnet opposed to the first magnet in parallel with the lead screw. The second provided
Is realized by the magnet.

The repulsive force or attractive force of the first magnet and the second magnet provided so as to face each other acts so that the clearance between these magnets becomes the same, while the teeth are used. Since it is rotatably attached to the tooth receiving portion, even if the optical pickup and the lead screw are inclined, the tooth and the lead screw can always be kept parallel.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a feed mechanism for an optical pickup according to the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing the overall configuration of the feed mechanism of the optical pickup of the present invention. As shown in FIG. 1, the feed mechanism of the optical pickup according to the present invention includes a base member 20, a guide rail 1 and a main rail 3 attached to the base member 20 in parallel with each other via a tilt adjusting mechanism 19.
An optical pickup 2 held by the rails 1 and 3 and moving along the rails, a lead screw 4 extending in parallel with the rails 1 and 3, and a feed motor 13 for rotating the lead screw 4 are provided. I have.

The optical pickup 2 condenses a laser beam on the information recording medium 18 by a condensing lens 2a to record / reproduce information. The guide rail 1 and the main rail 3 support the optical pickup 2 and serve as a guide for moving the optical pickup 2 in the radial direction of the information recording medium 18. The tilt adjusting mechanism 19 has a sandwich structure including a tilt adjusting screw, a rail, and a coil spring (not shown). By rotating the tilt adjusting screw, the rail is moved up and down, and the rails 1 and 3 with respect to the base member 20 are moved. The tilt of the optical pickup 2 is adjusted by changing the distance. The lead screw 4 has a function of a feed screw shaft, one end of which is fixed to a base member 20 by a screw receiver 14, and the other end of which is connected to a feed motor 13 via gears 11 and 12. The optical pickup 2 and the lead screw 4 are connected by a connecting portion 15 including the teeth receiver 5 and the teeth 6.

FIG. 2 is a sectional view taken along line AA in FIG. 1. FIG. 2 shows the structure of a first embodiment of a connecting portion 15 connecting the optical pickup 2 and the lead screw 4 of the optical pickup mechanism of the present invention. Show. As shown in FIG.
Are fixed to the optical pickup 2 with screws or the like, and hold the teeth 6. The teeth receiver 5 and the teeth 6 are connected via a hemispherical seat 5a provided on the teeth receiver 5 and a hemispherical projection 6a provided on the teeth 6, and the teeth 6 are driven by a coil spring 7 for holding down the teeth. It is urged against the receiver 5.

In FIG. 2, the open end (lead screw side end) of the tooth 6 is engaged with the lead screw 4 via teeth 6b provided on the lower side. Magnets 8a and 8b are provided symmetrically with respect to the center of the teeth 6 above the open end, and an opposing magnet 9 is provided above these magnets 8. The opposing magnet 9 is fixed to the base member 20 via a magnet yoke 10 and extends in parallel with the lead screw 4.
The magnets 8 and 9 are arranged with the same poles facing each other so as to repel each other, and the repulsive force always biases the teeth 6 toward the lead screw 4.

FIG. 3 is a plan view showing the structure of the connecting portion 15 shown in FIG. As shown in FIG. 3, the teeth 6 are hemispherical stoppers 25 in the moving direction of the optical pickup 2.
Is held by The stoppers 25 are provided on the squares of the teeth 6, and all four have the same shape. The ends of the stoppers 25 are in contact with the side surfaces of the teeth 6, respectively.
When the optical pickup 2 moves, the movement of the teeth in the moving direction is restricted.

FIG. 4 is a front view showing the structure of the connecting portion 15 shown in FIG. As shown in FIG. 4, the tooth 6 has two teeth 6b, 6 corresponding to the thread groove 4a of the lead screw 4.
b, and is engaged with the lead screw 4 via the teeth.

The above-described feed mechanism of the optical pickup of the present invention operates as follows. The rotation of the feed motor 13 is transmitted to the lead screw 4 via the gears 12 and 11, and the lead screw 4 rotates. By this rotation, the optical pickup 2 connected to the lead screw 4 via the teeth 6 moves in the radial direction of the information recording medium 18 along the main rail 3 and the guide rail 1 to record / reproduce information. . At this time, the condenser lens 2a of the optical pickup 2
When there is a tilt error in the optical axis of the laser light condensed by the above, the tilt adjusting mechanism 19 operates to raise and lower the guide rail 1 and / or the main rail 3 to correct the tilt error.
As a result, as shown in FIG. 5, an inclination occurs between the optical pickup 2 and the lead screw 4. In the apparatus of the present invention, the teeth 6 are rotatably attached to the teeth receiver 5, and The teeth 6 are provided with magnets 8a and 8b having the same magnetic characteristics symmetrically at the center of the teeth 6, and opposed magnets 9 are provided facing the magnets 8a and 8b in parallel with the lead screw 4. No inclination occurs between the screws 4. That is, the teeth 6 are rotatable with respect to the teeth receiver 5 by the hemispherical projections 6a and the seats 5a, and the opposed magnets 9 and the magnets 8a, 8b provided on the teeth 6
And the repulsive force F1 = F2 generated between the magnets 8a and 8b and the opposing magnet 9 causes the magnet 8a and the opposing magnet 9 and the magnet 8b and the opposing magnet 9 to urge each other. Rotation is performed so that the clearances become equal, and the lead screw 4 is always engaged in parallel.

FIG. 6A is a sectional view showing the structure of a second embodiment of the feed mechanism of the optical pickup of the present invention shown in FIGS. 2 to 4, and FIG. 6B is a sectional view of FIG. B-)
It is sectional drawing in the B line. As shown in FIGS. 6 (a) and 6 (b), the teeth receiver 5 and the teeth 6 each have a semi-cylindrical projection 30 and a corresponding semi-cylindrical seat 31.
And are connected by. In this embodiment, a semi-cylindrical projection 3
0 and the seat 31 that receives it extend in the moving direction of the optical pickup 2, and the rotation of the teeth 6 is restricted in the moving direction of the optical pickup 2. Therefore, in this example, it is not necessary to provide the stopper 25 shown in FIG.

FIG. 7 is a diagram showing the configuration of a third embodiment according to the feed mechanism of the optical pickup of the present invention.
FIG. 7A is a cross-sectional view thereof, and FIG. 7B is a cross-sectional view thereof along line CC. In the present embodiment, the projections 33 and the seats 32 that form the connection portion between the teeth 6 and the teeth receiver 5 are formed in a semi-cylindrical shape, similarly to the second embodiment shown in FIG. Contrary to the example, the optical pickup 2 is extended in a direction orthogonal to the moving direction of the optical pickup 2 so as to limit the rotation of the teeth 6 in this direction. The second and third embodiments can be suitably used when the tilt adjustment is performed only in one axis direction.

FIG. 8 is a sectional view showing the structure of a fourth embodiment of the feed mechanism of the optical pickup according to the present invention. In the present embodiment, a pair of fixed magnets 26 a and 26
b was used. These magnets 26a, 26
b is fixed to the teeth 6 and the optical pickup 2 so that the same poles are opposed to each other, and the teeth 6 are pressed against the teeth receiver 5 by the repulsive force of the magnets 26a and 26b.

FIG. 9 is a sectional view showing the structure of a fifth embodiment of the feed mechanism of the optical pickup according to the present invention. As shown in FIG. 9, in this embodiment, the tip of the tooth 6 is extended beyond the lead screw 4, and a magnet 35a is provided below the tip, and the magnet 35a is provided below the tip.
And a facing magnet 35b extending in parallel with the lead screw 4 is provided. The magnets 35a and 35b are arranged so that different magnets are opposed to each other and attract each other. The magnets 35a and 35b urge the tips of the teeth 6 downward so that the teeth 6b of the teeth 6 are always in the screw grooves 4a of the lead screw 4. I'm pushing.

Although the embodiments of the present invention have been described in detail above, the feed mechanism of the optical pickup according to the present invention is not limited to the configuration of the above-described embodiment, and various other forms may be used. be able to. For example, a projection may be formed instead of the seat on the tooth receiver 5 side, and a seat may be provided on the tooth 6 side.

[0025]

As described above, according to the feed mechanism of the optical pickup of the present invention, even if the tilt of the optical pickup and the lead screw is caused by the operation of the tilt adjusting mechanism of the optical disk device, the optical pickup and the lead screw are not moved. Since the teeth at the connection part with the screw can always be held parallel to the lead screw, it is possible to prevent an accident that the teeth come off the lead screw. Further, the load of the feed motor does not fluctuate due to the inclination between the optical pickup and the lead screw.

[Brief description of the drawings]

FIG. 1 is a plan view showing an overall configuration of a feed mechanism of an optical pickup according to the present invention.

FIG. 2 is a cross-sectional view taken along the line AA shown in FIG.

FIG. 3 is a plan view of a connecting portion shown in FIG. 2;

FIG. 4 is a front view showing an arrangement of a connecting portion and a lead screw shown in FIG. 2;

FIG. 5 is a front view showing an arrangement of a connecting portion and a lead screw in a state where a tilt adjusting mechanism is operated.

FIG. 6A is a cross-sectional view illustrating a configuration of a connecting portion according to a second embodiment of the present invention, and FIG.
It is sectional drawing in the BB line | wire shown to (a).

FIG. 7A is a side sectional view showing a configuration of a connecting portion according to a third embodiment of the present invention, and FIG. 7B is a sectional view taken along line CC of FIG. 7A. FIG.

FIG. 8 is a cross-sectional view illustrating a configuration of a connecting portion according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view showing a configuration of a connecting portion according to a fifth embodiment of the present invention.

FIG. 10 is a diagram illustrating a configuration of a feed mechanism of a conventional optical pickup.

[Explanation of symbols]

 Reference Signs List 1 guide rail 2 optical pickup 3 main rail 4 lead screw 4a screw groove 5 tooth receiver 5a, 30, 33 seat 6 tooth 6a, 31, 32 projection 6b tooth 7 coil spring 8, 9, 25, 35 magnet 13 feed motor 19 tilt Adjusting mechanism 20 Base member 25 Stopper

Claims (13)

[Claims] 1. A base member (20) and two guide rails (1, 1) mounted parallel to each other on said base member.
3), an optical pickup (20) that moves while being guided by the guide rail, a lead screw (4) that extends in parallel with the guide rail, and is configured to be rotatable in the axial direction thereof, and the lead screw. And a connecting portion (15) for connecting the optical pickup and the lead screw. The optical pickup is rotated by rotating the lead screw. In a feed mechanism of an optical pickup for moving in a predetermined direction, the connecting portion is rotatably engaged with a tooth receiving portion (5) fixed to the optical pickup, and one end is rotatably engaged with the tooth receiving portion. The tooth (6) engaged with the lead screw and the other end of the tooth are kept parallel to the tooth and the lead screw. And an urging means (8, 9) for urging the lead screw. 2. A hemispherical protruding portion (6) provided on the tooth, wherein an engaging portion between the tooth and the tooth receiving portion is provided.
a) and a hemispherical seat (5a) corresponding to the shape of the protruding portion provided on the tooth receiving portion, and the feed mechanism controls the movement of the tooth in the moving direction of the optical pickup. The feed mechanism of an optical pickup according to claim 1, further comprising stopper means for restricting, wherein the teeth and the teeth receiving portion are rotatable in two axial directions. 3. A hemispherical seat corresponding to a shape of the hemispherical seat provided on the tooth and a shape of the protruding portion provided on the tooth receiving portion, wherein an engaging portion between the tooth and the tooth receiving portion is provided. The feed mechanism includes stopper means for restricting the movement of the teeth in the moving direction of the optical pickup, and the teeth and the teeth receiving portion are rotatable in two axial directions. The feed mechanism of an optical pickup according to claim 1, wherein: 4. A semi-cylindrical protruding portion (31, 32) provided on the tooth, the semi-cylindrical seat corresponding to the shape of the protruding portion, wherein an engaging portion between the tooth and the tooth receiving portion is provided. The feed mechanism of the optical pickup according to claim 1, wherein the teeth and the teeth receiving portion are rotatable in one axial direction. 5. An engaging portion between the tooth and the tooth receiving portion includes a semi-cylindrical seat provided on the tooth and a projection corresponding to the shape of the seat. The feed mechanism of the optical pickup according to claim 1, wherein the teeth receiving part is rotatable in one axis direction. 6. The semi-cylindrical projection and the semi-cylindrical seat are provided in a direction that restricts movement of the teeth in a moving direction of the optical pickup. Or the feed mechanism of the optical pickup according to 5. 7. The semi-cylindrical projection and the semi-cylindrical seat are provided in a direction that restricts movement of the teeth in a direction orthogonal to a moving direction of the optical pickup. The feed mechanism of an optical pickup according to claim 4 or 5, wherein 8. A feed mechanism for an optical pickup according to claim 1, wherein said urging means for urging said teeth against said lead screw is a magnet (8, 9). 9. A biasing means for biasing the teeth to the lead screw includes a first magnet (8) provided at an end of the teeth on a lead screw side, and a biasing means parallel to the lead screw, and The feed mechanism of the optical pickup according to claim 8, wherein the feed mechanism is constituted by a second magnet (9) provided to face the first magnet. 10. A method according to claim 1, wherein the first magnet is provided above an end of the tooth on the lead screw side, and the first magnet and the second magnet have magnetism repelling each other. 10. The feed mechanism of the optical pickup according to claim 9, wherein the teeth are urged against the lead screw. 11. A tip end of the tooth on a lead screw side extends to a position beyond the lead screw, wherein the first magnet is provided below a tip end of the tooth. 10. The optical pickup feed mechanism according to claim 9, wherein the teeth are urged against the lead screw by providing the first magnet and the second magnet with magnets that attract each other. . 12. An optical pickup feed mechanism according to claim 1, wherein said teeth are pressed against said teeth receiving portion by a coil spring. 13. The device according to claim 1, wherein said teeth are pressed by magnets provided opposite to each other with a momentary force repelling each other with respect to said teeth receiving portion. The feed mechanism of the optical pickup described in the above.