JP2003346351A - Optical disk drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk drive which can adjust the deviation of a normal line of an optical pickup, using a simple structure. <P>SOLUTION: A fixing spring 5 and a position adjustment screw 3, clamping a main spindle 10 against the fixing spring 5, are disposed in the vicinity of both ends of the main spindle 10 for setting the direction of the movement of the optical pickup 1. The position adjustment screw 3 moves the main spindle in the direction parallel to the recording surface of an optical disk as the distance from its center of rotation to the contact surface contacting to the main spindle 10 varies according to the rotation. <P>COPYRIGHT: (C)2004,JPO

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 an optical disk device capable of adjusting a displacement of a normal in a moving direction of an optical pickup.

[0002]

2. Description of the Related Art Information is recorded or reproduced on an optical disk such as a CD or a DVD using a disk device which reads and writes the recording surface of the optical disk using an optical pickup. FIG. 5 shows a cross section of a general optical disk device. The optical disk device includes an optical pickup 1, a disk rotation motor 2, a disk support member 12, and a disk discharge tray 13.

[0003] The disc ejection tray 13 is used for the optical disc 1.
4 is carried into the optical disk device. The optical disk 14 carried into the optical disk device is sandwiched between the disk support member 12 and a turntable attached to the disk rotation motor 2, and is fixed by magnetic force or the like. The disk rotation motor 2 rotates the optical disk 14 via a turntable. The optical pickup 1 moves in the radial direction of the optical disc 14 while
Read and write to the recording surface of.

[0004]

By the way, in the optical disk device, when the objective lens of the optical pickup 1 and the recording surface of the optical disk 14 are not in an appropriate positional relationship, the quality of recording or reproduction often deteriorates. Are known. For example, when the center of the disk rotation motor 2 (optical disk) and the direction of movement of the center of the objective lens of the optical pickup 1 have a normal displacement that causes a displacement, the left and right track displacement is detected. Secondary laser (E-
Since the phase shift occurs in the F signal) and the amplitude of the tracking error signal decreases, the quality of recording or reproduction on the optical disc deteriorates.

[0005] In the optical disk device, high precision is required particularly for assembling the optical pickup mechanism for moving the optical pickup 1 in the radial direction of the optical disk 14. 2. Description of the Related Art In a disk device for recording or reproducing a high-density optical disk such as a DVD having a smaller track pitch than a CD, a higher precision is required for its components and assembly. However, there is a limit to the accuracy of individual components and the accuracy of assembly. Therefore, in places where high accuracy is required, measures have been taken to satisfy the required accuracy by performing fine adjustment after assembly.

For example, Japanese Patent Application Laid-Open No. 2000-242931 discloses that the position of a disk rotation motor is fixed to a mechanical chassis, and a main axis and a sub-axis of an optical pickup mechanism for moving an optical pickup in a track direction of an optical disk are moved relative to the mechanical chassis. A technique for finely adjusting the optical pickup mechanism by making the optical pickup mechanism movable. According to the technology described in this publication, a main shaft or a sub shaft is sandwiched between a shaft fixing holder and an adjustment cam, and the distance of the main shaft or the sub shaft from the mechanical chassis is changed by rotating the adjustment cam to adjust a normal deviation. Alternatively, skew adjustment is performed. However, this technique has a problem that the number of parts increases, the structure becomes complicated, and the cost increases.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem and to provide an optical disk apparatus capable of easily adjusting the positional deviation between the center of the optical disk and the track moving direction of the objective lens of the optical pickup.

[0008]

In order to achieve the above object, an optical disk device according to the present invention comprises: a pair of guide shafts for supporting an optical pickup movably in a radial direction of the optical disk; A pair of position adjustment units for adjusting a normal line shift generated between a moving direction of an optical focal point and a center of the optical disk, and adjusts positions near one end of the guide shaft in a direction parallel to the disk surface. A pair of position adjusters, each of which comprises an elastic member and a screw for pressing the guide shaft against the elastic member, the screw being in contact with the center of the screw and the guide shaft. The distance to the contact surface is changed by rotation of the screw.

In the optical disk device of the present invention, both ends of one guide shaft (main shaft) of the optical pickup are held by being sandwiched between a screw and an elastic member such as a spring.
By changing the distance from the surface where the screw contacts the spindle with the rotation center of the screw by the rotation of the screw, the spindle is moved in a direction parallel to the recording surface of the optical disk with a simple structure. be able to.

In the optical disk device of the present invention, it is preferable that the other of the guide shafts is movable by moving the guide shaft in a direction parallel to one of the disk surfaces. The other guide shaft (sub shaft) of the optical pickup can be held so as to be finely movable in accordance with the movement of the main shaft.

[0011] In the optical disk device of the present invention, the screw may have an elliptical cylindrical shape at the screw head forming the contact surface, or the screw head may have a tapered shape at the contact surface. You may have. When the screw head has an elliptical cylindrical shape, the position of the main shaft can be adjusted within a range corresponding to the difference between the major axis and the minor axis of the elliptical shape. Also, when using a tapered screw whose screw head diameter changes from the top of the screw head to the bottom of the screw head,
The position of the spindle can be adjusted in a range corresponding to the difference between the diameter of the screw head at the uppermost part and the diameter of the screw head at the lowermost part.

[0012] It is preferable that the optical disc apparatus of the present invention further includes a skew adjusting section adjacent to one of the position adjusting sections for adjusting the distance between the vicinity of the end of the guide shaft and the disk surface. In this case, the position of the spindle can be adjusted in two directions, a direction parallel to the recording surface of the optical disk and a direction perpendicular to the recording surface of the optical disk.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings based on embodiments of the present invention. FIG. 1 is a plan view of an optical disc device according to an embodiment of the present invention as viewed from the front side (lens side) of an optical pickup. FIG. 2 is a plan view of the optical disk device of FIG. 1 as viewed from the back side. The optical pickup mechanism of the optical disk device is mounted on a mechanical chassis 7 together with the disk rotation motor 2, and includes an optical pickup 1, a position adjusting screw 3, a holding spring 4, a fixing spring 5, a skew adjusting screw 9, a main shaft 10, and a sub shaft. 11 is provided. Hereinafter, a direction parallel to the moving direction of the optical pickup is called az direction, a direction perpendicular to the z direction and parallel to the recording surface of the optical disk 14 is called an x direction, and a direction perpendicular to the recording surface of the optical disk 14 is called ay direction. Called direction.

The optical pickup 1 has an objective lens for irradiating the optical disc 14 with laser light, and moves in the z direction along a main axis 10 and a sub axis 11. At one end (skew adjustment side) of the main shaft 10, a skew adjustment screw 9 for moving one of the ends of the main shaft 10 in the y direction is arranged. Spindle 1
The other end of 0 (the skew reference side) is held by the mechanical chassis 7 in a state in which fine movement is possible in accordance with the displacement of the main shaft 10 on the skew adjustment side in the y direction. Both ends of the main shaft 10 are further held on the mechanical chassis 7 by the position adjusting screw 3 and the fixed spring 5 for moving the main shaft in the x direction.

At both ends of the sub shaft 11, skew adjusting screws 9 for moving respective ends of the sub shaft 11 in the y direction are arranged. In addition, the sub shaft 11 is held by the mechanical chassis 7 in a state in which it can be finely moved in accordance with the movement of the main shaft 10 in the x direction. The main shaft 10 and the sub shaft 11 are restricted from moving in the y direction by the holding springs 4 provided at both ends. In the optical disk device, after assembling the components, the respective positions can be finely adjusted so that the main shaft 10 and the sub shaft 11 are parallel to each other. In the state shown in FIG. 1, the distance from a straight line passing through the center of the optical disk 14 (disk rotating motor 2) and parallel to the main shaft 10 to the main shaft 10,
The distance from the straight line passing through the center of the objective lens of the optical pickup 1 and parallel to the main axis 10 is different from the distance from the main axis 10, that is, the normal line shift occurs.

FIG. 3 is a three-dimensional perspective view of a part of FIG. 2 as viewed from the skew reference side of the main shaft 10. As shown in the figure, the skew adjustment screw 9 arranged on the skew adjustment side of the main shaft 10 is displaced in the y direction by rotation, and adjusts the displacement of the main shaft 10 in the y direction on the skew adjustment side with respect to the skew reference side. Further, the skew adjusting screws 9 arranged at both ends of the sub shaft 11 are attached to both ends of the sub shaft 11 respectively.
Adjust the directional displacement. At this time, each presser spring 4 regulates the movement in the y direction by adjusting the skew adjustment screw 9. Displacement of the spindle 10 in the y direction on the skew adjustment side, and
The skew adjustment is performed by appropriately adjusting the displacement in the y direction at each end of the sub shaft 11.

FIG. 4 is an enlarged view of a portion A in FIG. The main shaft 10 is held at both ends by being sandwiched between the position adjusting screw 3 and the fixed spring 5 in the x direction. As the position adjusting screw 3, a screw whose head is in an elliptical cylindrical shape is used. When the position adjusting screw 3 is rotated,
Depending on the rotation angle, the position adjusting screw 3 shown in FIG.
The distance (distance a) from the rotation center position to the position where the main shaft 10 contacts the position adjusting screw 3 can be changed.

By appropriately adjusting the rotation angle of the position adjusting screw 3, the displacement of the spindle 10 in the x direction can be adjusted, and the center position of the disk rotation motor 2 and the moving direction of the center position of the objective lens of the optical pickup can be adjusted. It is possible to adjust the deviation of the normal line that does not overlap. After the rotation angle of the position adjusting screw 3 is appropriately adjusted, the position adjusting screw 3 is fixed with an adhesive 6 such as a screw lock.

In this embodiment, the disk rotating motor 2
And the optical pickup mounted on the mechanical chassis,
Fine adjustment of the main shaft 10 in the x direction becomes possible. In addition, since the adjustment in the x direction is performed by the position adjusting screw 3 and the fixed spring 5,
The configuration for adjustment is simple. Therefore, it is possible to adjust the deviation of the normal line of the optical pickup after assembling the mechanical chassis 7 without increasing the cost.

In the above embodiment, a screw having an elliptical cylindrical head is used as the position adjusting screw 3, but the position adjusting screw 3 comes into contact with the main shaft from the center of rotation by rotating. Screws other than elliptical cylinder shapes that vary in distance to the surface can also be used. For example, as the position adjusting screw 3, a screw having a tapered head whose radius at the top of the screw head decreases toward the bottom of the screw head, which is shown as another example in FIG. Can also. In this case, when the main shaft is held at the same position in the y direction, the distance a shown in FIG. 4 can be shortened by rotating in the direction in which the tapered screw is loosened, and the distance is increased by rotating in the tightening direction. a can be lengthened.

Although the present invention has been described based on the preferred embodiment, the optical disk apparatus of the present invention is not limited to the above embodiment, but may be variously modified from the configuration of the above embodiment. Modified and changed optical disk devices are also included in the scope of the present invention. For example, if the fixed spring has a shape such as a U-shape on the side in contact with the main shaft, that is, a shape capable of restricting movement in both the x direction and the y direction, a configuration also serving as a holding spring can be provided. .

[0022]

As described above, the optical disk apparatus of the present invention can adjust the positional deviation between the center of the optical disk and the track moving direction of the objective lens of the optical pickup with a simple configuration.

[Brief description of the drawings]

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

FIG. 2 is a plan view of the optical disk device of FIG. 1 as viewed from the back surface side.

FIG. 3 is an exemplary perspective view showing a part of the optical disk device of FIG. 2;

FIG. 4 is an enlarged perspective view of A in FIG. 2;

FIG. 5 is a cross-sectional view generally showing a configuration of an optical disk device.

[Explanation of symbols]

1: Optical pickup 2: Disc rotation motor 3: Position adjustment screw 4: Holding spring 5: Fixed spring 6: adhesive 7: Mechanical chassis 9: Skew adjustment screw 10: Spindle 11: Counter shaft 12: Disk support member 13: Disc ejection tray 14: Optical disk

   ────────────────────────────────────────────────── ─── Continuation of front page    F term (reference) 5D068 AA02 BB01 CC01 EE05 EE17                       GG06                 5D117 AA02 CC07 JJ13 JJ15 KK01                       KK07 KK08 KK10 KK20 KK22

Claims (5)

[Claims] 1. An optical disc apparatus having a pair of guide shafts for supporting an optical pickup so as to be movable in a radial direction of an optical disc, wherein a normal line deviation occurring between a moving direction of an optical focus of the optical pickup and the center of the optical disc is adjusted. A pair of position adjusters for adjusting the positions of the guide shafts in the vicinity of one end of each of the guide shafts in a direction parallel to the disk surface, and each of the position adjusters includes an elastic member. A screw for pressing the guide shaft against the elastic member, wherein a distance between a center of the screw and a contact surface in contact with the guide shaft is changed by rotation of the screw. Optical disk device. 2. The optical disk device according to claim 1, wherein the other of the guide shafts is movable by movement in a direction parallel to one disk surface of the guide shaft. 3. The optical disk device according to claim 1, wherein said screw has a screw head that forms said contact surface has an elliptical cylindrical shape. 4. The optical disk device according to claim 1, wherein the screw has a tapered screw head constituting the contact surface. 5. The skew adjusting unit according to claim 1, further comprising a skew adjusting unit adjacent to one of the position adjusting units for adjusting a distance between a vicinity of an end of the guide shaft and a disk surface. An optical disk device as described in the above.