JP2003228852A - Optical pickup - Google Patents

Abstract

(57) [Problem] To provide an optical pickup which does not need to secure a space for skew adjustment of an objective lens on the side where an optical system is arranged. SOLUTION: An optical pickup 1 includes an actuator holding portion 2 provided on a base thereof, an optical system 3 arranged on one side B1 of the actuator holding portion, and a light beam radiated from the optical system. Objective lens 5 for focusing light on the recording surface and tilt mechanism 2 for controlling the tilt of the objective lens
5 and operating the moving member 7 from a direction orthogonal to the optical axis of the objective lens, and the actuator 4 disposed on the other surface side B2 of the actuator holding section, thereby moving the actuator to Y parallel to the optical axis. Moving direction changing means 6 for adjusting the skew of the objective lens by moving in the direction.

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 records information by converging light such as laser light on a recording surface of an optical disk which is a recording medium. ，
This is a device for performing reproduction and the like. 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, in order to properly adjust the angle of the objective lens with respect to the laser light with high accuracy,
The work of adjusting the skew of the objective lens by moving the actuator to which the objective lens is attached is performed.

FIG. 5 is a front view of a conventional optical pickup capable of skew adjustment, and FIGS. 5A and 5B show an operation when skew adjustment of an objective lens is performed. Figure 5
In the optical pickup 101 shown in (A) and (B), an actuator holding portion 102 is provided on a base (chassis) of the optical pickup 101.
The actuator 103 is held by 02. An objective lens 104 is attached to the actuator 103. A direction substantially parallel to the optical axis E of the objective lens 104 is defined as a Y direction, and directions orthogonal to the Y direction and forming three orthogonal directions are defined as an X direction and a Z direction. The “optical axis” is a straight line connecting the centers of the light source, lens, diaphragm, etc. of the optical system.

One side B of the actuator holder 102
An optical system 105 for emitting the laser light L is arranged at 1, and the optical system 105 has a light source 106, a photodetector 107, and the like. The actuator 103 is arranged on the other surface side B2 of the actuator holding portion 102,
It faces the optical disc D. The objective lens 104 is a light flux emitted from the optical system 105 (a light flux of the laser light L).
Is focused on the recording surface of the optical disc D. The actuator 103 is connected to the actuator holding portion 102 by a skew adjusting screw 109 or the like. Two skew adjusting screws 109 are provided in total in the X direction and the Z direction with respect to the optical axis E. By adjusting the screwing amount of the two skew adjusting screws 109, the actuator 10
3 can be moved in the direction of arrow C3 (Y direction substantially parallel to the optical axis E of the objective lens 104: vertical direction in the figure) to adjust the skew of the objective lens 104. The skew adjusting screw 109 is arranged from the one surface side B1 to the other surface side B2 direction of the actuator holding portion 102 and is screwed into the actuator base 110.

[0005]

Usually, when adjusting the skew of the objective lens, the skew of the actuator is adjusted while rotating the optical disk and irradiating the optical disk with laser light. In the case of the conventional optical pickup 101, in order to move the actuator 103 in the direction of the arrow C3 to adjust the skew of the objective lens 104, the skew adjusting screw 1 is moved from the one surface side B1 of the actuator holding portion 102 with the driver 111 or the like.
It is necessary to rotate 09 to adjust the screwing amount. This is because the optical disc D is rotating during the skew adjustment, so the actuator holding unit 10
This is because the adjustment work cannot be performed from the other side B2 of 2. Therefore, the space S for skew adjustment work is provided on the one side B1 of the actuator holding portion 102.
Must be secured.

However, various optical components constituting the optical system 105 are arranged on the one surface side B1 of the actuator holding portion 102 so as to have a considerably dense structure. In addition to this, a necessary optical system optical path is also provided. It is necessary to secure it. Since the amount of information recorded on the optical disc D is increasing more and more due to technological innovation in recent years, the configuration of the optical system 105 is complicated, the number of optical components is increased, and the overall size thereof is also increased. . Under these circumstances, the actuator 103 is moved to move the objective lens 104.
The space S for skew adjustment of the optical system 105
It is becoming difficult to secure it on the side of the arrangement position. When trying to secure the space S for skew adjustment, there is a large restriction on the degree of freedom in designing the optical system 105. Moreover, since the two skew adjusting screws 109 are normally provided 90 degrees apart, it is necessary to secure two spaces S for skew adjustment on the arrangement position side of the optical system 105. The constraint on the degree of freedom was a major issue.

The present invention has been made to solve such a problem, and secures a space for adjusting the skew of the objective lens by moving the actuator to which the objective lens is attached, on the arrangement position side of the optical system. The purpose is to provide an optical pickup that does not need to be kept.

[0008]

In order to achieve the above-mentioned object, an optical pickup according to the present invention is provided with an actuator holding portion provided on a base of the optical pickup and one surface side of the actuator holding portion. And an actuator and a moving direction changing means. The actuator has an objective lens for condensing the light flux emitted from the optical system on the recording surface of the optical disc and a tilt mechanism for controlling the inclination of the objective lens, and is arranged on the other surface side of the actuator holding portion. ing. The moving direction changing means is provided in at least one of the actuator and the actuator holding portion,
By operating the moving member from a direction substantially orthogonal to the optical axis of the objective lens, the actuator can be moved in the first direction substantially parallel to the optical axis to adjust the skew of the objective lens. The moving direction changing means for adjusting the skew of the objective lens is provided in at least one of two directions orthogonal to the optical axis.
In the optical pickup according to one preferred specific embodiment, the moving direction changing means has a taper portion and a screw portion, and the screw portion is rotatably screwed into the actuator holding portion, and the light of the objective lens is changed. The movable member is arranged so as to be movable in a direction substantially orthogonal to the axis, and the contact portion is formed at a corresponding position of the actuator. The taper portion of the moving member abuts the abutment portion of the actuator. Further, in an optical pickup according to another preferable specific aspect, the moving direction changing means has a taper portion and engages with the actuator holding portion in a direction substantially orthogonal to the optical axis of the objective lens. The movable member is disposed so as to be movable, and the contact portion is formed at a corresponding position of the actuator, and the tapered portion of the movable member is in contact with the contact portion of the actuator. In one of the two specific embodiments, as one preferable example, the taper portion is arranged at a position to press the contact portion of the actuator, and when the moving member is moved forward and backward with respect to the actuator, The actuator is configured to move toward and away from the actuator holding portion according to a change in the inclination angle of the taper portion while the contact portion is pressed by the taper portion. In addition, as another preferable example, the taper portion is arranged between the actuator and the actuator holding portion, and when the moving member is moved forward and backward with respect to the actuator, the actuator has the contact portion. While being supported by the tapered portion, the actuator holding portion may be separated or approached according to a change in the inclination angle of the tapered portion.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment according to the present invention will be described with reference to FIGS. (First Embodiment) FIG. 1 is a front view of an optical pickup according to a first embodiment of the present invention.
(B) shows the operation when adjusting the skew (adjusting the inclination) of the objective lens. In FIGS. 1 (A) and 1 (B),
The optical pickup 1 used in the optical disk device (not shown) can be moved by a moving mechanism (not shown) while being controlled in the radial direction of the optical disk D which is a recording medium. 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 (for example, laser light L) on the recording surface of the optical disc D by the objective lens 5 to record and reproduce information on the optical disc D. The optical disc D is a CD, a CD-ROM, a CD-R, a C.
D-RW, MD, MO, DVD-ROM, DVD-RA
M, DVD-R, DVD-RW and the like.

The optical pickup 1 includes an actuator holding portion 2 provided on a base (chassis) (not shown) of the optical pickup 1, an optical system 3 arranged on one side B1 of the actuator holding portion 2, and an actuator holding portion. Part 2
The actuator 4 is disposed on the other side B2 of the optical disc D and faces the optical disc D. The actuator 4 is
An objective lens 5 for converging a light beam (a light beam of the laser beam L) emitted from the optical system 3 on the recording surface of the optical disc D;
The tilt mechanism 25 controls the tilt of the objective lens 5. The actuator 4 is held by the actuator holding unit 2 so that the inclination of the objective lens 5 with respect to the light flux can be changed. In addition, a first direction substantially parallel to the optical axis E of the objective lens 5 (that is, a direction substantially perpendicular to the optical disc D) is defined as a Y direction, and a second direction orthogonal to the Y direction and forming three orthogonal directions, Let the 3rd direction be the X direction and the Z direction, respectively.

The optical pickup 1 is provided with a moving direction changing means 6 provided on at least one of the actuator 4 and the actuator holding portion 2 in order to adjust the skew of the objective lens 5. The moving direction changing means 6 is provided in at least one of two directions (X direction and Z direction) orthogonal to the optical axis E. In the illustrated optical pickup 1, in order to adjust the skew of the objective lens 5 with higher accuracy, the moving direction changing means 6 is provided in each of two directions (X direction and Z direction) orthogonal to the optical axis E. . The moving direction changing means 6 moves the moving member 7 from the direction substantially orthogonal to the optical axis E of the objective lens 5 in the direction of arrow C1 (the direction substantially orthogonal to the optical axis E of the objective lens 5, ie, X).
Direction and a direction horizontal to the Z direction: lateral direction in the figure) to move the actuator 4 in the direction of arrow C2 (Y direction substantially parallel to the optical axis E of the objective lens 5: vertical direction in the figure). The skew of the lens 5 can be adjusted.

Therefore, the moving direction changing means 6 has a moving member 7 and an abutting portion 36 formed at a corresponding position of the actuator 4. The moving member 7 has a tapered portion 35.
And a male thread portion 11 as a thread portion, and a male thread portion 1
1 is rotatably screwed into the actuator holding portion 2 and is arranged so as to be movable in directions (X direction and Z direction) substantially orthogonal to the optical axis E of the objective lens 5. And
The taper portion 35 of the moving member 7 contacts the contact portion 36 of the actuator 4. In the manufacturing process of the optical pickup 1, the skew adjustment of the objective lens 5 is performed by operating the moving member 7. That is, when the moving member 7 is moved in the plane direction (direction of arrow C1) parallel to the X direction and the Z direction, the actuator 4 moves according to the change in the inclination angle of the taper portion 35 in contact with the contact portion 36. The member 7 moves in a direction (direction of arrow C2) substantially orthogonal to the moving direction of the member 7.

The actuator holding portion 2 is fixed to the base of the optical pickup 1 and is integrally bent by a plate material. A rising portion 8 for mounting the moving member 7 is formed on the actuator holding portion 2 so as to be bent so as to rise from the bottom plate portion 9 at a substantially right angle, and is arranged in the X direction and the Z direction. A male thread portion 11 of the moving member 7 in the X direction is screwed into a female thread portion 10 as a thread portion formed on the rising portion 8 in the X direction. Similarly,
Since the threaded portion 10 is formed on the rising portion 8 in the Z direction,
The external thread 11 of the Z-direction moving member 7 is screwed in. The actuator 4 is attached with a lens holding portion 13 holding the objective lens 5, a supporting wire 14 supporting the lens holding portion 13, a wire supporting member 15 supporting the supporting wire 14, a wire supporting member 15 and the like. And an actuator base 16 and the like. The actuator base 16 is integrally formed by a plate-shaped member, and the yokes 19 to 22 and the like are fixed to the upper surface of the actuator base 16 in addition to the wire support member 15. A spherical seat portion 23 having an outer peripheral surface formed in a spherical shape is integrally formed on the lower portion of the actuator base 16 so as to project. The bottom plate portion 9 of the actuator holding portion 2 is provided with a ball seat receiving portion 12 having a spherical inner peripheral surface. The ball seat portion 23 of the actuator base 16 is slidably engaged with the ball seat receiving portion 12 of the actuator holding portion 2. This allows
The actuator 4 is held in the actuator holding portion 2 so that the skew can be adjusted. The actuator 4 can change the angle with respect to the actuator holder 2 by the ball seat 23 sliding on the ball seat receiver 12.

The lens holding section 13 is provided with a focus coil 17 and a tracking coil 18 for finely adjusting the position and orientation of the objective lens 5 with respect to the optical disc D. The objective lens 5 is composed of the coils 17 and 18, the yokes 19 to 22, the permanent magnets, and the like.
A tilt mechanism 25 is configured to control the tilt of the. It should be noted that although the present embodiment shows the case of the “lens center type” in which the objective lens 5 is arranged substantially in the center of the lens holding portion 13, the objective lens 5 is arranged outside the lens holding portion 13. "Lens offset type"
May be the case. Further, as a method of supporting the movable portion of the lens holding portion 13, a "wire suspension method" is used.
Although the case is illustrated, the movement in the focus direction may be moved up and down along the center shaft, and the movement in the tracking direction may be a case of the “axial sliding method” in which the movement is performed around the center shaft.

The optical system 3 has a light source 30 such as a semiconductor laser for generating a laser beam L, a photodetector 31, and various optical parts such as a reflection mirror, a lens and a diffraction grating (not shown). The photodetector 31 receives the laser light L reflected by the optical disc D and detects a focus error signal, a tracking error signal, a reproduction signal, and the like. Optical system 3
Most of the optical components and the optical path of the optical system constituting the above are arranged on the one surface side B1 of the actuator holding portion 2. The objective lens 5 also constitutes the optical system 3, but the objective lens 5 is
It is arranged on the other surface side B2 of the actuator holding portion 2.

The moving direction changing means 6 has a moving member 7 and a contact portion 36 that contacts the moving member 7. The male screw portion 11 of the moving member 7 is screwed into the screw portion 10 because it is formed in the actuator holding portion 2, and the taper portion 35 is provided.
Is formed in a conical shape at the tip of the moving member 7. The “tapered portion” is a portion having an inclined surface. The moving member 7 is arranged so as to be movable in a direction substantially orthogonal to the optical axis E of the objective lens 5 (for example, an X direction and a Z direction which are orthogonal to the Y direction and form three orthogonal directions). The contact portion 36 is provided in the actuator 4 in each of the X direction and the Z direction so as to contact the tapered portion 35 of the moving member 7. The contact portion 36 is formed on the upper surface side of the end portion of the actuator base 16 to which the actuator 4 is attached. The contact portion 36 has a tapered portion 3 attached thereto.
The taper portion 35 is formed so that the surface 5 comes into surface contact and slides smoothly.
Taper (or cross-section arc) corresponding to the inclination angle of
Is formed in. If the taper portion 35 can move relatively easily with respect to the contact portion 36, the contact portion 36
May not be formed in a tapered shape.

The taper portion 35 has a conical taper surface (inclined surface) and is provided on the opposite side of the actuator 4 from the actuator holding portion 2 (that is, the actuator base 16).
Is arranged on the upper surface side). That is, the tapered portion 35
Is arranged at a position to press the contact portion 36 of the actuator 4. When the moving member 7 is moved forward and backward with respect to the actuator 4 in the direction of arrow C1 by performing an operation of adjusting the screwing amount of the male screw portion 11 of the moving member 7, the actuator 4 has a taper contact portion 36. While being pressed by the portion 35, the actuator holding portion 2 approaches the actuator holding portion 2 in the direction of arrow C2 in accordance with the change in the inclination angle of the tapered portion 35,
It is designed to be separated. As a result, the objective lens 5
The skew of the objective lens 5 can be adjusted by moving the actuator 4 to which is attached. Figure 1 (A),
(B) shows a case where the contact portion 36 approaches and separates from the bottom plate portion 9 of the actuator holding portion 2.

The actuator base 16 is always pressed against the actuator holding portion 2 as shown by an arrow G by another mechanism (not shown). Note that this configuration is the same as in the optical pickup shown in FIGS. Therefore, the actuator 4
Is positioned and held by the separate mechanism and the moving member 7 while being pressed in the direction of the actuator holding portion 2. The light beam emitted from the optical system 3 is the objective lens 5
The moving member 7 in the X direction (and, so that the objective lens 5 is arranged at a right angle to the central axis of the light beam emitted from the optical system 3).
By adjusting the position in the Z direction), the skew of the objective lens 5 is adjusted. In the state shown in FIG. 1A, the luminous flux and the optical axis E do not match, whereas the operation of adjusting the screwing amount of the external thread 11 of the moving member 7 is performed to adjust the skew of the objective lens 5. By doing so, as shown in FIG. 1B, the light flux and the optical axis E can be accurately matched. As a result, optical aberration does not occur when the laser light L passes through the objective lens 5, and it is possible to prevent the signal level from decreasing.

FIG. 2 is a front view of an optical pickup 1a according to a modification of the first embodiment, and FIG.
(B) shows the operation when adjusting the skew of the objective lens 5. 2 to 4, the same or corresponding parts as those of the embodiment shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described. In the optical pickup 1a shown in FIGS. 2A and 2B, the bottom plate portion 9 of the actuator holding portion 2 is used.
Further, a recess 40 for arranging the moving member 7 movably in the direction of arrow C1 is formed. The taper portion 35 formed on the tip side of the moving member 7 is arranged between the actuator 4 and the actuator holding portion 2.

A moving direction changing means 6a for adjusting the skew of the objective lens 5 is provided on at least one of the actuator 4 and the actuator holding portion 2. The moving direction changing means 6a is provided in at least one of two directions (X direction and Z direction) orthogonal to the optical axis E. In the illustrated optical pickup 1a, in order to adjust the skew of the objective lens 5 with higher accuracy, the moving direction changing means 6a is provided in each of two directions (X direction and Z direction) orthogonal to the optical axis E. . Moving direction changing means 6a
Is operated by moving the moving member 7 in the direction of arrow C1 from a direction substantially orthogonal to the optical axis E of the objective lens 5 to move the actuator 4 in the Y direction (arrow C2) substantially parallel to the optical axis E.
Direction) to adjust the skew of the objective lens 5. Therefore, the moving direction changing means 6a is
It has a moving member 7 and a contact portion 36 a formed at a position corresponding to the actuator 4. The moving member 7 has a taper portion 35 and a male screw portion 11, and the male screw portion 11 is rotatably engaged with the actuator holding portion 2 so as to be substantially orthogonal to the optical axis E of the objective lens 5 (X Direction and Z direction)
It is arranged to be movable. Then, the tapered portion 35 of the moving member 7 contacts the contact portion 36a of the actuator 4. The moving member 7 is screwed into the screw portion 10 because it is formed on the actuator holding portion 2.
The contact portion 36a is provided in the actuator 4 in the X direction and the Z direction so as to contact the tapered portion 35 of the moving member 7. The contact portion 36a is formed on the lower surface side of the end portion of the actuator base 16 to which the actuator 4 is attached. The contact portion 36a has a tapered portion 3 so that the tapered portion 35 comes into surface contact therewith and slides smoothly.
It is formed in a taper shape (or an arc shape in cross section) corresponding to the inclination angle of 5. The contact portion 36a may not be formed in a tapered shape as long as the tapered portion 35 can move relatively easily with respect to the contact portion 36a.

The taper portion 35 is arranged between the actuator 4 and the actuator holding portion 2. When the moving member 7 is moved forward and backward in the direction of arrow C1 with respect to the actuator 4 by performing an operation for adjusting the screwing amount of the external thread 11 of the moving member 7, the actuator 4 has a contact portion 36a with a tapered portion. In a state of being in contact with and supported by 35,
In accordance with the change in the inclination angle of the taper portion 35, the actuator holding portion 2 is separated and approaches the actuator holding portion 2 in the arrow C2 direction. That is, as shown in FIG.
Is retracted with respect to the actuator 4, the contact portion 36 a of the actuator 4 is close to the actuator holding portion 2. Further, as shown in FIG. 2B, the moving member 7 is operated to move the taper portion 35 to the actuator 4
If it moves forward with respect to the contact portion 36a of the actuator 4,
Is supported by the tapered portion 35 and is supported by the actuator holding portion 2
Will be separated from. As a result, the light flux emitted from the optical system 3 (light flux of the laser light L) is shown in FIG.
When the optical axis E of the objective lens 5 does not match as shown in FIG. 2, the moving member 7 is operated in the direction of the arrow C1 as shown in FIG. The skew of the objective lens 5 can be adjusted by moving the actuator 4 in the direction of arrow C2 so as to match with high accuracy.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
3A and 3B are front views of the optical pickup 1b according to the embodiment of the present invention, and FIGS. 3A and 3B show an operation when the skew of the objective lens 5 is adjusted. The optical pickup 1b shown in FIGS. 3A and 3B is provided with a moving direction changing means 6b for adjusting the skew of the objective lens 5.
The moving direction changing unit 6b is provided on at least one of the actuator 4 and the actuator holding unit 2. The moving direction changing means 6b is provided in at least one of two directions (X direction and Z direction) orthogonal to the optical axis E. In the illustrated optical pickup 1b, in order to adjust the skew of the objective lens 5 with higher accuracy, the moving direction changing means 6b is provided in each of two directions (X direction, Z direction) orthogonal to the optical axis E. . Moving direction changing means 6b
By operating the moving member 7b in the direction of arrow C1 from a direction substantially orthogonal to the optical axis E of the objective lens 5,
The actuator 4 is moved in the Y direction (arrow C
The objective lens 5 can be adjusted in skew by moving in two directions. Therefore, the moving direction changing means 6b
Has a moving member 7b and an abutting portion 36b formed at a position corresponding to the actuator 4. The moving member 7b is
It has a tapered portion 35b and is arranged so as to be engaged with the actuator holding portion 2 and movable in a direction (X direction and Z direction) substantially orthogonal to the optical axis E of the objective lens 5.
Then, the tapered portion 35b of the moving member 7b contacts the contact portion 36b of the actuator 4.

The moving member 7b is engaged with the actuator holding portion 2 so as to be movable only in the radial direction (arrow C1 direction) about the optical axis E. The contact portion 36b is provided in the actuator 4 in the X direction and the Z direction so as to contact the tapered portion 35b of the moving member 7b. The contact portion 36b is formed on the upper surface side of the end portion of the actuator base 16 to which the actuator 4 is attached. The contact portion 36b is formed in a taper shape (or an arc shape in cross section) corresponding to the inclination angle of the taper portion 35b so that the taper portion 35b comes into surface contact therewith and slides smoothly. In addition, the tapered portion 35b with respect to the contact portion 36b
The contact portion 36b may not be formed in a tapered shape as long as it can move relatively easily.

The tapered portion 35b has a flat tapered surface (inclined surface) and is arranged on the opposite side of the actuator 4 from the actuator holding portion 2 (upper surface side of the actuator base 16). That is, the tapered portion 35b is arranged at a position to press the contact portion 36b of the actuator 4. When the moving member 7b is operated to move the moving member 7b forward and backward with respect to the actuator 4 in the direction of the arrow C1, the actuator 4 has the abutting portion 36b pressed by the tapered portion 35b. The actuator holding portion 2 is moved toward and away from the actuator holding portion 2 in the direction of arrow C2 in accordance with the change in the inclination angle of 35b. Therefore, in the state where the moving member 7b is advanced as shown in FIG. 3A, when the optical axis E of the objective lens 5 is tilted with respect to the luminous flux, the moving member 7b is moved as shown in FIG. 3B. When the taper portion 35b is operated and retracted with respect to the actuator 4, the contact portion 36b of the actuator 4 is separated from the actuator holding portion 2 while being pressed by the taper portion 35b. In this way, by moving the actuator 4 and adjusting the skew of the objective lens 5,
The optical axis E can be matched with the light flux with high accuracy.

FIG. 4 is a front view of an optical pickup 1c according to a modification of the second embodiment, and FIG.
(B) shows the operation when adjusting the skew of the objective lens 5. The optical pickup 1c shown in FIGS. 4A and 4B is provided with a moving direction changing means 6c for adjusting the skew of the objective lens 5. The moving direction changing unit 6c is provided on at least one of the actuator 4 and the actuator holding unit 2. Moving direction changing means 6
c is provided in at least one of two directions (X direction and Z direction) orthogonal to the optical axis E. In the illustrated optical pickup 1c, in order to adjust the skew of the objective lens 5 with higher accuracy, the moving direction changing means 6c is provided in each of two directions (X direction and Z direction) orthogonal to the optical axis E. . The moving direction changing means 6c moves the actuator 4 in the Y direction (direction of arrow C2) substantially parallel to the optical axis E by operating the moving member 7c from a direction substantially orthogonal to the optical axis E of the objective lens 5. The skew of the objective lens 5 can be adjusted. Therefore, the moving direction changing means 6c has a moving member 7c and a contact portion 36c formed at a corresponding position of the actuator 4.
The moving member 7c has a tapered portion 35c, is engaged with the actuator holding portion 2, and is arranged so as to be movable in a direction (X direction and Z direction) substantially orthogonal to the optical axis E of the objective lens 5. . Then, the contact portion 36 of the actuator 4
The tapered portion 35c of the moving member 7c abuts on c.

The moving member 7c is engaged with the actuator holding portion 2 so as to be movable only in the radial direction (direction of arrow C1) about the optical axis E. The contact portion 36c is provided in the actuator 4 in the X direction and the Z direction so as to contact the tapered portion 35c of the moving member 7c. The contact portion 36c is formed on the lower surface side of the end portion of the actuator base 16 to which the actuator 4 is attached. The contact portion 36c is formed in a tapered shape (or an arc shape in cross section) corresponding to the inclination angle of the tapered portion 35c so that the tapered portion 35c comes into surface contact with the contact portion 36c and slides smoothly. In addition, the taper portion 35c is different from the contact portion 36c.
The contact portion 36c may not be formed in a tapered shape as long as it can move relatively easily.

The moving member 7c is engaged with the actuator holding portion 2 so as to be movable only in the radial direction (direction of arrow C1) about the optical axis E. The taper portion 35c has a flat taper surface (inclined surface) formed thereon, and the actuator 4
And the actuator holding portion 2 are sandwiched between them. This moving member 7 is operated by operating the moving member 7c.
When c is moved forward and backward with respect to the actuator 4 in the direction of the arrow C1, the actuator 4 has the abutting portion 36c in contact with the tapered portion 35c and is supported by the tapered portion 3c.
According to the change of the inclination angle of 5c, the actuator holding portion 2 is separated and approaches in the direction of arrow C2.

That is, when the optical axis E of the objective lens 5 is tilted with respect to the light beam when the taper portion 35c is retracted with respect to the actuator 4 as shown in FIG. 4 (B), the moving member 7c is operated to move the taper portion 35c forward with respect to the actuator 4 so that the contact portion 36c of the actuator 4 is moved.
However, it is separated from the actuator holding portion 2 while being supported by the tapered portion 35c. In this way, by moving the actuator 4 and adjusting the skew of the objective lens 5, the optical axis E can be accurately matched with the luminous flux.

As described above, in the optical pickups 1, 1a to 1c of the present invention, the moving members 7, 7b and 7c are moved in the directions (X direction, X direction) substantially orthogonal to the optical axis E of the objective lens 5.
By operating from the Z direction), the actuator 4 can be moved in the direction of the arrow C2 to adjust the skew of the objective lens 5. This skew adjustment is performed as one of the final adjustment operations in the manufacturing process of the optical pickups 1, 1a to 1c. Since the skew adjustment work can be performed from a direction substantially orthogonal to the optical axis E, a space for this work can be easily secured in a direction substantially orthogonal to the optical axis E, and the objective lens 5 can be highly accurately. The skew can be adjusted. Since the skew adjustment work of the objective lens 5 can be performed on the upper surface side (that is, the surface side facing the actuator 4) of the bottom plate portion of the actuator holding portion 2, it is arranged on the one surface side B1 of the actuator holding portion 2. It never interferes with the optical components of the optical system 3 and the optical path of the optical system. That is, it is not necessary to secure a space for adjusting the skew of the objective lens 5 on the arrangement position side of the optical system 3 (that is, the one surface side B1). As a result, it is possible to freely arrange the optical components of the optical system 3 and the optical path of the optical system 3 by freely using the space on the one surface side B1 of the actuator holding portion 2, and the degree of freedom in design is expanded. When the above-described skew adjustment of the objective lens 5 is completed, the actuator 4 is positioned and fixed on the actuator holding portion 2 with an adhesive or the like so as not to move.

In the optical pickups 1, 1a to 1c, the moving members 7, 7b and 7c having the tapered portions are arranged on the actuator holding portion 2, and the contact portions 36, 36b and 36c are formed on the actuator base 16 of the actuator 4. ing. Therefore, it is not necessary to machine the actuator base 16 to form the tapered portion, and the actuator base 16 can be integrally formed from a plate material easily and inexpensively. In addition, the moving member is connected to the actuator 4
Alternatively, the abutting portion may be formed on the actuator holding portion 2.

Although the set of the moving member and the contact portion provided in the X direction of one pickup and the set of the moving member and the contact portion provided in the Z direction have the same structure, the moving member and the contact portion in the X direction are shown. The configuration of the set of contact portions may be different from the configuration of the set of the moving member and the contact portion in the Z direction. The moving direction changing means 6, 6a to 6c of the optical pickups 1 and 1a to 1c change the linear movement of the moving members 7, 7b and 7c into the linear movement of the actuator 4, but the moving members can be rotated. Then, this rotational movement is performed by the actuator 4
The moving direction changing means for changing to the linear movement of For example, by rotating the moving member in a direction substantially orthogonal to the optical axis E of the objective lens 5, the actuator 4 may be moved in the Y direction (arrow C2 direction) to adjust the skew of the objective lens 5. Good. In addition,
In an optical pickup that does not require such highly accurate skew adjustment, the moving direction changing means for adjusting the skew of the objective lens 5 is provided only in one direction orthogonal to the optical axis E (for example,
It may be provided only in the X direction or only in the Z direction). In the drawings, the same reference numerals indicate the same or corresponding parts.

[0032]

Since the present invention is constructed as described above, it is necessary to secure a space for moving the actuator to which the objective lens is attached to adjust the skew of the objective lens on the side where the optical system is arranged. Absent.

[Brief description of drawings]

FIG. 1 is a front view of an optical pickup according to a first embodiment of the present invention.

FIG. 2 is a front view of an optical pickup according to a modified example of the first embodiment.

FIG. 3 is a front view of an optical pickup according to a second embodiment of the present invention.

FIG. 4 is a front view of an optical pickup according to a modified example of the second embodiment.

FIG. 5 is a front view of a conventional optical pickup.

[Explanation of symbols]

1,1a-1c Optical pickup 2 Actuator holder 3 Optical system 4 actuators 5 Objective lens 6,6a-6c Moving direction changing means 7,7b, 7c Moving member 11 Male thread (screw) 25 Tilt mechanism 35, 35b, 35c Tapered part 36, 36a to 36c abutting portion B1 One side B2 Other side D optical disc E optical axis L laser light (light) X direction Second direction Y direction First direction Z direction Third direction

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Miki Takada             3-3-6 Nihonbashi Ningyocho, Chuo-ku, Tokyo               Within Sumida Technologies Co., Ltd. F term (reference) 5D117 AA02 CC07 HH12 KK01 KK08                       KK20                 5D118 AA06 AA14 BA01 DC03 FC10

Claims (6)

[Claims] 1. An actuator holding part provided on a base of an optical pickup, an optical system arranged on one side of the actuator holding part, and a light beam emitted from the optical system on a recording surface of an optical disc. An actuator having an objective lens for condensing and a tilt mechanism for controlling the tilt of the objective lens and arranged on the other surface side of the actuator holding section; and an actuator provided on at least one of the actuator and the actuator holding section, By operating the moving member from a direction substantially orthogonal to the optical axis of the objective lens,
An optical pickup comprising: a moving direction changing means for adjusting the skew of the objective lens by moving the actuator in a first direction substantially parallel to the optical axis. 2. The light according to claim 1, wherein the moving direction changing means for adjusting the skew of the objective lens is provided in at least one of two directions orthogonal to the optical axis. pick up. 3. The moving direction changing means has a taper portion and a screw portion, and the screw portion is rotatably engaged with the actuator holding portion and is substantially orthogonal to the optical axis of the objective lens. And a contact portion formed at a corresponding position of the actuator, wherein the tapered portion of the movable member is in contact with the contact portion of the actuator. The optical pickup according to claim 1 or 2, characterized in that. 4. The moving member, wherein the moving direction changing means has a taper portion and is arranged so as to be engaged with the actuator holding portion and movable in a direction substantially orthogonal to the optical axis of the objective lens. And a contact portion formed at a corresponding position of the actuator, wherein the tapered portion of the moving member contacts the contact portion of the actuator. The optical pickup described in 2. 5. The taper portion is arranged at a position for pressing the contact portion of the actuator, and when the moving member is moved forward and backward with respect to the actuator, the actuator has the contact portion In the state of being pressed by the taper portion, the actuator holding portion approaches the actuator holding portion according to the change of the inclination angle of the taper portion,
The optical pickup according to claim 3, wherein the optical pickup is separated from each other. 6. The taper portion is arranged between the actuator and the actuator holding portion, and when the moving member is moved forward and backward with respect to the actuator, the actuator has the contact portion with the taper portion. In a state of being supported by the actuator, the actuator holder is separated from the actuator holder in accordance with a change in the inclination angle of the tapered portion,
The optical pickup according to claim 3 or 4, wherein the optical pickups approach each other.