JP2003317266A - Optical pickup - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable optical pickup by which the forming die of a base holding an actuator can easily be produced, the number of parts for a skew adjusting means is reduced, and assembling work is simplified. <P>SOLUTION: The optical pickup 1 is provided with the actuator 3, the base 4, and the skew adjusting means 5 which constantly pushes the actuator to the base in a state where skew adjustment is possible. An stretching spring 10 constituting the skew adjusting means is inserted and arranged into a bore 16 which is bored at the base to form a step part 15. The large diameter part 41 of the stretching spring is engaged with the stage part, and the other side engaging part 18 of the stretching spring is engaged with the part to be engaged 19 of the actuator to energize the actuator to the side of the base. <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 pickup that records and reproduces information by condensing light with an objective lens on a recording surface of an optical disk, and particularly skew adjustment (tilt adjustment) of the objective lens. Regarding possible optical pickups.

[0002]

2. Description of the Related Art An optical pickup is used in an optical disk device such as an optical disk reproducing device and an optical disk recording / reproducing device, and collects information such as light by converging light such as laser light on a recording surface of an optical disk which is a recording medium. It is a device for recording and reproducing. As described above, the optical pickup has a function of irradiating the recording surface of the optical disc with the laser light. Therefore, if the angle of the objective lens with respect to the laser light is not properly adjusted, optical aberration occurs and the signal level is increased. And other inconveniences occur. Therefore, when manufacturing an optical pickup, a skew adjustment work is performed in which an actuator to which the objective lens is attached is moved to appropriately adjust the angle of the objective lens with respect to the laser light with high accuracy.

FIG. 9 is a sectional view of a conventional optical pickup, and FIG. 10 is a sectional view of another conventional optical pickup. Figure 9
The optical pickup 101 shown in FIG. 1 includes an actuator 102 having an objective lens, a base 103 that holds the actuator 102, and a skew adjusting unit 1 that constantly presses the actuator 102 on the base 103 so that the skew can be adjusted.
04 and. Then, the skew adjusting unit 104
Thus, the actuator 102 is biased toward the base 103 side. The skew adjusting means 104 has a compression spring 105 provided on the base 103 and a screw member 106 that supports the compression spring 105 and is screwed into the actuator 102. Then, the actuator 102 is urged toward the base 103 by the spring force of the compression spring 105.

[0004]

However, in the skew adjusting means 104, since the screw member 106 is required in addition to the compression spring 105, the number of parts is large and the assembling work of these parts is complicated. In addition, a work of locking the screw member 106 is also required to prevent loosening.

On the other hand, the optical pickup 101 shown in FIG.
a is an actuator 102a having an objective lens,
A base 103a for holding the actuator 102a and a base 103 for enabling skew adjustment of the actuator 102a.
The skew adjusting means 104a that is constantly pressed against a is provided. Then, the actuator 102a is biased toward the base 103a by the skew adjusting means 104a. The skew adjusting means 104a has a tension spring 105a. The tension spring 105a is used for the actuator 10
The actuator 102a is urged toward the base 103a by being locked by the locked portion 107a of 2a and the locked portion 108a formed to project from the base 103a. However, with this skew adjusting means 104a, although the number of parts is small, it is necessary to form the locked portion 108a in a protruding manner on the base 103a. As a result, the mold for molding the base 103a becomes complicated, and it is difficult to manufacture and maintain the mold. In addition, the tension spring 105a is secured to the locked portion 108a in a narrow space inside the base 103a.
It was troublesome to lock it on. The locked portion 108 of the base 103a integrally formed of synthetic resin or the like
In order to prevent the deformation and damage of a, and to improve the reliability of the optical pickup 101a, the strength of the locked portion 108a and its mounting portion should be improved, and the base 103a should be made of a strong material. It has been necessary to take into consideration various factors such as changing to, or limiting the magnitude of the spring force of the tension spring 105a.

As another conventional technique, an optical pickup in which a leaf spring is used as the skew adjusting means and the leaf spring urges the actuator toward the base is also known. However, in this type of skew adjusting means, the number of parts tends to increase and the assembling work is complicated.

The present invention has been made to solve the above problems, and a mold for molding a base for holding an actuator can be easily manufactured, and the number of parts of the skew adjusting means can be reduced. It is an object of the present invention to provide a highly reliable optical pickup which can be reduced in number and simplified in assembling work.

[0008]

In order to achieve the above object, an optical pickup according to the present invention comprises an actuator having an objective lens, a base for holding the actuator, and a base for holding the actuator so that the skew can be adjusted. And a bias adjusting member that constitutes the skew adjusting means, and is inserted and arranged in a biasing member hole formed in the base to form a step,
The one-side locking portion of the biasing member is locked to the step portion, and the other-side locking portion of the biasing member is locked to the locked portion of the actuator to move the actuator to the base side. Is urged to. The urging member is a tension spring, and the urging member hole is composed of a concentric small-diameter hole and a concentric large-diameter hole, and is formed through the base to be substantially parallel to the optical axis of the objective lens. The tension spring has a small diameter portion, a large diameter portion partially having an outer diameter larger than the inner diameter of the small diameter hole, and the other side engaging portion provided in the small diameter portion. When the tension spring is inserted into the biasing member hole, the small-diameter portion penetrates the small-diameter hole, and the large-diameter portion is arranged in the large-diameter hole. It is preferable that the one side locking portion is configured by being locked to the step portion. The large-diameter portion of the tension spring is formed substantially at right angles to the small-diameter portion, or the central axis of the large-diameter portion is substantially parallel to the central axis of the small-diameter portion. Is preferred. Further, it is preferable that the outer diameter of the large diameter portion of the tension spring is at least larger than the inner diameter of the small diameter hole and is substantially equal to the inner diameter of the large diameter hole. Further, it is preferable that the large-diameter portion and the other-side locking portion that constitute the one-side locking portion are formed in a substantially arc shape or a polygonal shape.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment according to the present invention will be described below with reference to FIGS. 1 to 5 are views showing an embodiment of the present invention. Figure 1,
2 is a perspective view and a plan view of the optical pickup, FIG. 3 is a sectional view taken along line III-III of FIG. 2, FIG. 4 is a sectional view taken along line IV-IV of FIG. 2, and FIG. It is a perspective view of a spring. 1 to 4, an optical pickup 1 used in an optical disc device (not shown) is movable by a moving mechanism (not shown) while being controlled in a radial direction of an optical disc D which is a recording medium. There is. In the optical disk device, the optical pickup 1 is moved to a desired position by the moving mechanism while the optical disk D is being rotationally driven by the drive motor. Then, the optical pickup 1 focuses light (here, laser light) on the recording surface of the optical disc D by the objective lens 2 to record and reproduce information on the optical disc D. The optical disc D includes a CD, a CD-ROM, a CD-R, a CD-RW, and an M.
D, MO, DVD-ROM, DVD-RAM, DVD-
R, DVD-RW, etc.

The optical pickup 1 has an actuator 3 having an objective lens 2, a base 4 for holding the actuator 3, and a base 4 for adjusting the skew of the actuator 3.
And a skew adjusting means 5 which is constantly pressed against.
The actuator 3 is arranged on the upper surface 7 side of the base 4 and faces the optical disc D. The optical pickup 1 has a "two-story structure" in which an actuator 3 is mounted on a base 4. The optical pickup 1 is provided with an optical system 6 for emitting laser light. The base 4 is integrally formed of synthetic resin or the like.
The actuator 3 has an objective lens 2 that focuses the light flux (light flux of laser light) emitted from the optical system 6 onto the recording surface of the optical disc D. The actuator 3 is held on the base 4 so that the inclination of the objective lens 2 with respect to the light flux can be changed (that is, the skew can be adjusted).
For convenience of description, the direction parallel to the optical axis B of the objective lens 2 (focus direction, that is, the direction perpendicular to the optical disc D) is defined as the X direction. The Z direction is the direction orthogonal to the X direction and the tracking direction (the radial direction of the optical disc D), and the direction orthogonal to the X and Z directions is the Y direction.

In the present embodiment (including modified examples described later), the "lens center type" optical pickup 1 in which the objective lens 2 is arranged substantially at the center of the actuator 3.
Shows the case. The present invention can also be applied to a “lens offset type” optical pickup in which the objective lens is arranged outside the actuator. A tension spring 10 is used as a biasing member that constitutes the skew adjusting means 5 and biases the actuator 3 toward the base 4. The biasing member may be an elastic member other than the tension spring as long as it biases the actuator 3 toward the base 4. The tension spring 10 has a hole 16 for a spring, which is a hole for a biasing member formed in the base 4 to form a step 15.
It is arranged to be inserted. Tensile spring 10 One side locking portion 1
7 is locked to the step portion 15, and the other side locking portion 18 of the tension spring 10 is locked to the locked portion 19 of the actuator 3 to urge the actuator 3 to the base 4 side.

The skew adjusting means 5 has, in addition to the tension spring 10, a first skew adjusting section 21 and a second skew adjusting section 22. The tension spring 10, the first skew adjusting section 21, and the second skew adjusting section 22 are arranged at predetermined positions around the actuator 3 in a plan view. As a result, the actuator 3 is held on the base 4 at a total of three positions so that the skew can be adjusted, and the tension spring 10
Is always pressed against the base 4. The first skew adjusting unit 21 is orthogonal to the recording surface of the optical disc D and in the plane (in the X and Z planes) in the radial direction (radial direction) of the optical disc D, as indicated by an arrow C, The inclination of B can be adjusted (skew adjustment). The second skew adjusting unit 22 is orthogonal to the recording surface of the optical disc D and in the plane (X and Y planes) in the tangential direction (tangential direction) of the track, as indicated by the arrow E, the optical axis. The inclination of B can be adjusted (skew adjustment). In the first skew adjusting unit 21 and the second skew adjusting unit 22, the skew adjustment is performed by screwing the male screw 31 into the actuator base 26 of the actuator 3 through the through hole of the base 4. The work of skew adjusting the objective lens 2 by the first and second skew adjusting units 21 and 22 is performed in the manufacturing process of the optical pickup 1.

The actuator 3 includes a lens holding portion 23 that holds the objective lens 2, a support wire 24 that supports the lens holding portion 23, a wire support member 25 that supports the support wire 24, and a wire support member 25. It has an actuator base 26 to which is attached, a tilt mechanism 8 having a focus coil, a tracking coil, and the like to control the tilt of the objective lens 2, and other members. The actuator base 26 is integrally formed of a plate-shaped member, and in addition to the wire support member 25, a yoke, a permanent magnet and the like are also attached to the actuator base 26. At the bottom of the actuator base 26,
A spherical seat portion 27 whose outer peripheral surface is formed into a convex spherical surface is integrally formed to project. The base 4 is provided with a spherical seat receiving portion 28 whose inner peripheral surface is concave and which is substantially concentric with the spherical seat portion 27. Ball seat 27 of the actuator base 26
Engages with the ball seat receiving portion 28 of the base 4 in a slidable manner. Since the ball seat portion 27 slides with respect to the ball seat receiving portion 28 about the optical axis B of the objective lens 2, the actuator 3 can swing and change the angle with respect to the base 4. Therefore, the skew is adjustable on the base 4.

The optical system 6 has a light source such as a semiconductor laser for generating a laser beam, a photodetector, and various optical parts such as a reflecting mirror, a lens and a diffraction grating. The photodetector receives the laser light reflected on the recording surface of the optical disc D, detects a reproduction signal, detects the tilt of the recording surface of the optical disc D, and outputs a focus error signal, a tracking error signal, and the like. Most of the optical components constituting the optical system 6 and the optical path of the optical system are arranged on the inner space 29 of the base 4 and the lower surface 30 side of the base 4. Although the objective lens 2 is attached to the actuator 3, this objective lens 2 also constitutes the optical system 6. When controlling the state of the optical pickup 1 (position, posture, etc. of the objective lens 2) during use of the optical disc device, the conversion unit converts the detection result regarding the inclination of the recording surface of the optical disc D detected by the photodetector. Is converted into an electric signal and output to the control unit as an electric signal. The control unit controls the current supplied to the focus coil, the tracking coil, and the like of the tilt mechanism 8 based on this electric signal. Then, the lens holding unit 23 and the objective lens 2 are controlled in their positions to move in the focus direction and the tracking direction, whereby the tilt adjustment of the objective lens 2 is automatically performed.

Next, the tension spring 10 of the skew adjusting means 5
The spring hole 16 and the like will be described. 4 and 5
As shown in FIG. 3, the spring hole 16 is composed of a concentric small-diameter hole 35 and a large-diameter hole 36, and the optical axis B of the objective lens 2 is attached to the base 4.
Is formed almost parallel to The spring hole 16 is formed in a circular cross section having a central axis CL. The small diameter hole 35 is arranged on the actuator 3 side and opens on the upper surface 7 of the base 4. The large-diameter hole 36 is arranged on the side opposite to the position where the actuator 3 is arranged, and opens on the lower surface 30 of the base 4. By forming the large-diameter hole 36 in communication with the small-diameter hole 35, the step portion 15 is formed at the boundary between both holes 36, 35.
Is formed. The step portion 15 has a central axis C of the hole 16 for spring.
It has a step surface in a direction substantially perpendicular to L. The step surface of the step 15 may be a tapered surface that is formed obliquely with respect to the central axis CL.

The locked portion 19 of the actuator 3 is integrally formed on the actuator base 26 so as to project therefrom.
The locked portion 19 is arranged immediately above the spring hole 16, and its tip is bent upward. As a result, the other side locking portion 18 of the tension spring 10 is locked by the locked portion 19
Once locked, there is no risk of disengagement from the locked portion 19.

The tension spring 10 includes a small diameter portion 40 and a large diameter portion 4
1 and the other side locking portion 18 provided on the small diameter portion 40. The small diameter portion 40 is wound with a winding diameter smaller (preferably slightly smaller) than the inner diameter of the small diameter hole 35 so as to penetrate the small diameter hole 35. The other side locking portion 18 is formed by bending an upper end portion of the small diameter portion 40 upward. The large-diameter portion 41 is formed continuously with the small-diameter portion 40 and is inserted and arranged in the large-diameter hole 36.
Has an outer diameter greater than the inner diameter of the. The outer diameter of the large diameter portion 41 is at least larger than the inner diameter of the small diameter hole 35, and is formed to be substantially equal to the inner diameter of the large diameter hole 36. When the tension spring 10 is inserted into the spring hole 16, the small diameter portion 40 penetrates the small diameter hole 35, and the large diameter portion 41 is arranged in the large diameter hole 36 and is locked by the step portion 15 to be on one side. Locking part 17
Are configured. The large diameter portion 41 is formed substantially perpendicular to the small diameter portion 40. That is, the central axis of the large diameter portion 41 and the central axis of the small diameter portion 40 are substantially at right angles. When the tension spring 10 is inserted into the spring hole 16, the large diameter portion 41
It can be easily inserted and attached from the lower surface 30 side of the base 4 by holding it with a finger or the like, and the assembling workability is good. In the tension spring 10, the large diameter portion 41 and the other side locking portion 18 are substantially arcuate, which is preferable in that the tension spring 10 can be easily manufactured.

Next, a procedure for incorporating the actuator 3 into the base 4 will be described. The actuator 3 is placed on the base 4, and the ball seat portion 27 of the actuator 3 is brought into close contact with the ball seat receiving portion 28 of the base 4. Next, in the first skew adjusting section 21 and the second skew adjusting section 22, the male screw 31 is inserted into the through hole of the base 4 and is screwed into the actuator base 26. On the other hand, tension spring 1
Insert 0 into the spring hole 16. In this case, the tension spring 10
Will be inserted from the lower surface 30 side of the base 4 toward the upper surface 7 side. The winding diameter of the small diameter portion 40 of the tension spring 10 is the small diameter hole 3
Since it is smaller than 5, the small diameter portion 40 penetrates the large diameter hole 36 and the small diameter hole 35, and the other side locking portion 18 formed at the tip of the small diameter portion 40 projects outward from the upper surface 7. The other side locking portion 18 facing upward is locked to the locked portion 19 of the actuator 3.

On the other hand, the large diameter portion 41 of the tension spring 10 is inserted and arranged in the large diameter hole 36. At this time, since the outer diameter of the large-diameter portion 41 is made larger than the inner diameter of the small-diameter hole 35, the large-diameter portion 41 is locked to the step portion 15 without entering the small-diameter hole 35, and serves as the one-side locking portion 17. Exert function. Therefore,
The tension spring 10 has a large diameter portion 41 (one side locking portion 17).
Is locked to the stepped portion 15, and the other side locking portion 18 is locked to the locked portion 1
9 is retained by the spring 9 in the spring hole 16 in a state of being pulled against the spring force. As a result, the actuator 3 is constantly pressed against the base 4 while being biased toward the base 4 by the spring force of the tension spring 10. next,
The light flux of the laser light emitted from the optical system 6 is aligned with the optical axis B of the objective lens 2 (that is, the objective lens 2 is arranged at a right angle to the central axis of the light flux emitted from the optical system 6). As described above), the skew of the objective lens 2 is adjusted by adjusting the male screws 31 of the first and second skew adjusting units 21 and 22. In this way, by adjusting the skew of the objective lens 2, the angle of the objective lens 2 with respect to the laser light is properly adjusted, so that the light flux and the optical axis B can be accurately matched. In the optical pickup 1 assembled in this way, optical aberration does not occur when the laser light passes through the objective lens 2, and it is possible to prevent a decrease in signal level.

In the optical disc device to which the optical pickup 1 is attached, the optical pickup 1 is moved to a desired position by the moving mechanism while the optical disc D is being rotationally driven by the drive motor. Then, the laser light generated by the optical system 6 is focused on the recording surface of the optical disc D by the objective lens 2 to record and reproduce information on the optical disc D. At this time, the tilt adjustment of the objective lens 2 is automatically performed by the tilt mechanism 8.

6 to 8 are views showing modified examples of this embodiment. FIG. 6 is a sectional view of the optical pickup 1a.
FIG. 7 is a perspective view of a tension spring 10a provided in the optical pickup 1a shown in FIG. 6, and FIG. 8 is a perspective view of a tension spring 10b according to another modification. In the modified examples shown in FIGS. 6 to 8, the same or corresponding parts as those of the present embodiment shown in FIGS. 1 to 5 are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described.

In the tension spring 10a shown in FIGS. 6 and 7, the central axis (winding axis) of the large diameter portion 41a provided in the tension spring 10a is substantially parallel to the central axis (winding axis) of the small diameter portion 40. Is formed. That is, the central axis of the large-diameter portion 41a is formed slightly eccentric from the central axis of the small-diameter portion 40, but "parallel" includes the case where both central axes are substantially concentric. The optical pickup 1a includes an actuator 3, a base 4 and a skew adjusting means 5a. The skew adjusting means 5a constantly presses the actuator 3 on the base 4 so that the skew can be adjusted. The tension spring 10a as a biasing member constitutes the skew adjusting means 5a, and the actuator 3 is mounted on the base 4
It is biased to the side. The tension spring 10a is inserted and arranged in a spring hole 16 having a step 15 formed in the base 4. Large diameter portion 41 as one side locking portion of the tension spring 10a
a is locked to the step portion 15, and the other side locking portion 18 of the tension spring 10 a is locked to the locked portion 19 of the actuator 3. In the spring hole 16 of the optical pickup 1a, the axial dimension G of the large diameter hole 36 is smaller than that of the spring hole 16 shown in FIG. 4, but other configurations are shown in FIG. Same as 16.

The tension spring 10a has a small-diameter portion 40 and a large-diameter portion 41a partially having an outer diameter larger than the inner diameter of the small-diameter hole 35.
And the other-side locking portion 18 provided on the small diameter portion 40. The large-diameter portion 41a is continuous with the small-diameter portion 40, is inserted and arranged in the large-diameter hole 36, and is locked to the step portion 15. Large diameter portion 41a and the other side locking portion 18
Is preferable because it can be easily manufactured because it has a substantially arc shape.
When the tension spring 10a is inserted into the spring hole 16, the small diameter portion 40 penetrates the small diameter hole 35, and the large diameter portion 41a becomes the large diameter hole 3.
6 and is locked by the step portion 15 to form the one side locking portion 17. The large diameter portion 41a is formed such that its central axis is substantially parallel to the central axis of the small diameter portion 40. Therefore, even if the axial dimension G of the large diameter hole 36 is small, the large diameter portion 41a has a large diameter. It is inserted and arranged in the hole 36.
As a result, the thickness T of the base 4 can be reduced, and the entire optical pickup 1a can be made compact.

The biasing member in the present invention may be a tension spring 10b having a shape as shown in FIG. In the tension spring 10b, the large-diameter portion 41b serving as the one-side locking portion and the other-side locking portion 18b are each formed in a substantially triangular shape, but even when they are formed in other polygonal shapes. Good. This tension spring 10b also has the same effect as the present embodiment shown in FIGS. 1 to 5. The large diameter portion 41
If b is formed substantially concentrically with the small diameter portion 40, the same operational effect as the modified example shown in FIGS. 6 and 7 can be obtained.

As described with reference to FIGS. 1 to 8, in the optical pickups 1 and 1a of the present invention, the tension springs 10 and 10 are used.
The configuration for locking the a and 10b on the base 4 side can be simplified. That is, the tension springs 10, 10a, 1
By providing the step portion 15 in the spring hole 16 for inserting the 0b, the tension springs 10, 10a, 1 are attached to the step portion 15.
The large diameter portions 41, 41a, 41b of 0b can be locked. As a result, a locked portion for locking the tension springs 10, 10a, 10b on the base 4 side (the locked portion 10 in FIG. 10).
8a) is not required to be projectingly formed on the base, the structure of the mold for molding the base 4 is simplified, the mold can be easily manufactured, and the maintenance of the mold is also easy. Is.

Since the actuator 3 is pressed against the base 4 only by the tension springs 10, 10a, 10b, the number of parts of the skew adjusting means 5, 5a can be reduced,
In addition, the work of assembling the tension spring can be simplified. Large diameter portions 41, 41 of the tension springs 10, 10a, 10b
Since a and 41b are locked by the step portion 15 formed in the spring hole 16 and having a simple structure, there is no fear of damage or deformation of the step portion 15. Therefore, consideration of changing the material of the base and improving the strength of the locked portion is unnecessary. Further, the skew adjusting means 5 and 5a can always press the actuator 3 against the base 4 with a predetermined spring force even during the assembling work of the optical pickups 1 and 1a, the vibration of the optical disk device, and the long-term use. Yes, optical pickup 1,1a
The reliability of can be improved. In particular, even if the optical pickup device 1a is violently vibrated when the optical disk device is mounted on an automobile, the tension springs 10, 10a and 10b are
Since it is firmly locked by the step portion 15, the optical pickups 1 and 1a exhibit high reliability. It is possible to use the tension springs 10, 10a, 10b having a large spring force as compared with the conventional one. Tensile springs 10, 10a, 10b
Since a commercial item can be used, the cost is reduced.

If the tension springs 10, 10a, 10b are inserted into the spring holes 16 and the other side engaging portion 18 is engaged with the engaged portion 19 provided on the actuator 3, the large diameter portions 41, 41 are formed.
The a and 41b are inevitably locked to the step portion 15. Therefore, it is possible to omit a special member such as a screw for locking the tension springs 10, 10a, 10b to the base 4 and a mounting process associated with the mounting, so that the assembling work is simplified.
The cost can also be reduced. The case where the biasing member having the one-side locking portion and the other-side locking portion is integrally formed is shown, but the one-side locking portion and the other-side locking portion are provided as separate parts. It may be attached to the biasing member.

As described above, the embodiment of the present invention (including modified examples)
However, the present invention is not limited to the above-described embodiment, and various modifications and additions can be made within the scope of the gist of the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts.

[0029]

Since the present invention is configured as described above, it is possible to easily manufacture a die for molding the base for holding the actuator, reduce the number of parts of the skew adjusting means, and install it. The work can be simplified and the reliability of the optical pickup can be improved.

[Brief description of drawings]

1 to 5 are views showing an example of an embodiment of the present invention, and FIG. 1 is a perspective view of an optical pickup.

FIG. 2 is a plan view of the optical pickup.

3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a perspective view of a tension spring.

FIG. 6 to FIG. 8 are views showing modifications of the present embodiment. FIG. 6 is a sectional view of the optical pickup, which is equivalent to FIG.

7 is a perspective view of a tension spring provided in the optical pickup shown in FIG.

FIG. 8 is a perspective view of a tension spring according to another modification.

9 is a cross-sectional view of a conventional optical pickup, which is equivalent to FIG.

10 is a cross-sectional view of another conventional optical pickup, which is equivalent to FIG.

[Explanation of symbols]

1,1a Optical pickup 2 Objective lens 3 actuators 4 bases 5,5a Skew adjusting means 10, 10a, 10b Tension spring (biasing member) 15 steps 16 Spring hole (biasing member hole) 17 One side locking part 18, 18b Other side locking part 19 Locked part 35 small hole 36 Large hole 40 Small diameter part 41, 41a, 41b Large diameter part (one side locking part) B optical axis

Continued front page    F term (reference) 5D117 AA02 HH13 KK08 KK11 KK22                 5D118 AA03 AA06 AA12 BA01 FB13                       FC07 FC10

Claims (5)

[Claims] 1. An actuator having an objective lens,
A base for holding the actuator and a skew adjusting means for constantly pressing the actuator on the base so that the skew can be adjusted are provided. An urging member forming the skew adjusting means is provided on the base to be stepped. Part of the biasing member is inserted into the hole for the biasing member, one locking portion of the biasing member is locked to the step portion, and the other locking portion of the biasing member is locked by the actuator. An optical pickup characterized in that the actuator is biased toward the base side by being locked to a portion. 2. The biasing member is a tension spring, and the biasing member hole is composed of a concentric small-diameter hole and a large-diameter hole, and the base is substantially parallel to the optical axis of the objective lens. The stepped portion is formed so as to penetrate therethrough, and the tension spring is provided in the small diameter portion, a large diameter portion having a portion having an outer diameter larger than the inner diameter of the small diameter hole, and the small diameter portion. When the tension spring is inserted into the biasing member hole, the small-diameter portion penetrates the small-diameter hole, and the large-diameter portion is formed in the large-diameter hole. The optical pickup according to claim 1, wherein the optical pickup is arranged and is locked to the step portion to form the one side locking portion. 3. The optical pickup according to claim 2, wherein the large diameter portion of the tension spring is formed substantially at right angles to the small diameter portion. 4. The optical pickup according to claim 2, wherein the large-diameter portion of the tension spring is formed such that its central axis line is substantially parallel to the central axis line of the small-diameter portion. 5. The optical pickup according to claim 2, wherein the large diameter portion and the other side locking portion are formed in a substantially arc shape or a polygonal shape.