JPH09128778A - Optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup made capable of precisely adjusting a radial skew by preventing from turning together when a damper base is fixed. SOLUTION: This optical pickup contains a skew adjustment mechanism rockingly adjustably attaching the damper base 13 of an actuator movably supporting an objective lens in the biaxial directions in the radial skew direction for an actuator base 15. In such a case, the skew adjustment mechanism contains guide parts 18 integrally provided on the actuator base so as to hold the damper base smoothly and movably and a screw 15c for fastening so as to approach the guide parts to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup for recording / reproducing an optical disc, and more particularly to an optical pickup capable of accurately performing radial skew adjustment.

[0002]

2. Description of the Related Art Conventionally, optical pickups are constructed as shown in FIGS. 3 and 4, for example. That is, in FIGS. 3 and 4, the optical pickup 1 includes a lens holder 3 for holding the objective lens 2, a focusing coil 3a and a tracking coil 3b wound around a coil bobbin provided in the lens holder 3, A suspension spring 5 that movably supports the lens holder 3 in the focusing direction F and the tracking direction Tr with respect to a damper base 4 that is fixedly arranged, and a suspension spring 5 that supports the damper base 4 in a radial direction R so that the swinging adjustment is possible. An actuator base 6 and a pickup base 7 that supports the actuator base 6 in a tangential direction Ta so that the swinging of the actuator base 6 is adjustable.

As shown in the drawing, the suspension springs 5 are provided with a total of four suspension springs 2 in total, two pairs, and the lens holder 3 and the damper base 4 are provided on both sides of the lens holder 3 respectively. By connecting, it connects mechanically and electrically.

[0004] The actuator base 6 is integrally formed with two yokes 6a and 6b. These yokes 6a and 6b are arranged so as to sandwich the lens holder 3 at an interval from a horizontal direction X perpendicular to the tracking direction.
The magnet 8 is provided on the inner surface facing the.

Further, the actuator base 6 has a rising portion 6c for fixing the damper base 4 in the X direction.
And a screw 6d that penetrates the rising portion 6c and is screwed into a screw hole 4a provided in the damper base 4, and a screw hole that penetrates the actuator base 6 from below and is screwed into a screw hole provided on the lower surface of the damper base 4. And a screw 6e for

The pickup base 7 has a support surface 7 for the actuator base 6 so as to support the actuator base 6 in an adjustable manner in the tangential direction Ta.
a. Further, the pickup base 7 includes a laser diode 7b, a beam splitter 7c, a rising mirror 7d, and a photodiode 7e.

According to the optical pickup 1 configured as described above, the light emitted from the laser diode 7b is reflected by the beam splitter 7c, then by the rising mirror 7d, and through the objective lens 2. Optical disc D
The light is focused on the signal surface (see FIG. 4). Then, the light reflected on the signal surface of the optical disk is reflected again by the rising mirror 7d via the objective lens 2, and is reflected by the beam splitter 7c.
, And then enter the photodiode 7e. Thus, information recorded on the signal surface of the optical disc can be detected based on the output signal from the photodiode 7e.

Here, the radial skew adjustment is performed as follows. First, the screw 6d is loosely tightened so that the damper base 4
With respect to the radial direction R. Then, the damper base 4 is swung around the screw 6d by advancing and retreating by rotation of the screw 6e against the leaf spring 7f, thereby performing radial skew adjustment of the damper base 4, and then firmly tightening the screw 6d. As a result, the damper base 4 is fixed to the actuator base 6. Thus, the skew of the damper base 4 is adjusted.

[0009]

However, in the optical pickup 1 thus constructed, the screw 6e is used.
After tightening the screw 6d after adjusting the radial skew of the damper base 4 with respect to the actuator base 6, the damper base 4 may rotate together with the rotation of the screw 6d, and the radial skew adjustment may shift.
There is a problem in that accurate radial skew adjustment cannot be performed.

In view of the above points, the present invention provides a skew adjusting mechanism for an optical pickup, in which co-rotation can be prevented when fixing the damper base, so that accurate radial skew adjustment can be performed. The purpose is to do.

[0011]

According to the present invention, the above-mentioned object is to provide a light emitting section, an objective lens for condensing light from the light emitting section onto a signal surface of an optical disk, and reflected light from the signal surface of the optical disk. Skew adjustment that attaches the light-receiving part that enters through the objective lens, the actuator that supports the objective lens so that it can move in two axial directions, and the damper base of the actuator that can be adjusted to swing in the radial skew direction with respect to the actuator base. In the optical pickup including a mechanism, the skew adjusting mechanism clamps the guide portion integrally provided on the actuator base so as to sandwich the damper base so as to move smoothly, and the guide portion so as to approach each other. It is achieved by an optical pickup, characterized in that it comprises a tightening screw.

In the optical pickup according to the present invention, the inner diameter of the guide portion is preferably slightly longer than the length of the damper base.

With the above arrangement, the damper base is fixedly held to the actuator base by tightening the tightening screw after the damper base is subjected to radial skew adjustment with respect to the actuator base. At that time, the damper base is fixed and held by being clamped by the guide portion by the tightening of the tightening screw, so that the rotation of the tightening screw is not directly transmitted to the damper base. The damper base will not rotate together by tightening the tightening screw.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. 1 and 2 show the configuration of an embodiment of an optical pickup according to the present invention.

In FIG. 1, an optical pickup 10 includes a lens holder 12 for holding an objective lens 11, a focusing coil 12a and a tracking coil 12b wound around a coil bobbin provided in the lens holder 12, and the lens. A suspension spring 14 for movably supporting a holder 12 in a focusing direction F and a tracking direction Tr with respect to a damper base 13 on which a holder 12 is fixedly arranged, and an actuator base for rotatably supporting the damper base 13 in a radial direction R. 15
And a pickup base 16 that supports the actuator base 15 so as to be swingably adjustable in the tangential direction Ta.
It is composed of

In the illustrated case, the suspension springs 14 are two pairs in total, and four suspension springs 14 in total.
Are arranged, and the lens holder 12 and the damper base 13 are connected on both sides of the lens holder 12, so that the lens holder 12 and the damper base 13 are mechanically and electrically connected.

The actuator base 15 is integrally formed with two yokes 15a and 15b. These yokes 15a and 15b are respectively connected to the lens holder 12
Are arranged so as to be spaced from the horizontal direction X perpendicular to the tracking direction, and the magnet 17 is provided on the inner surface of the one yoke 15a facing the lens holder 12.
Is provided.

In this case, the actuator base 15 is
A guide portion 18 composed of two rising portions 18a and 18b arranged so as to sandwich the damper base 13 in the X direction, a screw 15c penetrating the damper base 13 inserted between the guide portions 18, and from below. The actuator base 15 that pushes up the lower surface of the damper base 13.
And a screw 15d that is screwed into a screw hole provided in the.

The screw 15c penetrates one rising portion 18a of the guide portion 18, and at least a screw portion provided near the tip is screwed to the rising portion 18b of the guide portion 18. By tightening, the enlarged head of the screw 15c pushes the rising portion 18a with respect to the rising portion 18b, so that the rising portion 18a
The damper base 13 inserted between a and 18b can be sandwiched and fixedly held.

The inside of the guide portion 18, that is, the distance L between the two rising portions 18a and 18b is set slightly longer than the length La of the damper base 13, so that the screw 1
The enlarged head of 5c moves the rising portion 18a to the rising portion 1
It is possible to smooth the operation of pushing with respect to 8b, and to sandwich and hold the damper base 13 inserted between the rising portions 18a and 18b, so that the damper base 13 can be securely fixed and held.

The pickup base 16 has a support surface 16a for the actuator base 15 and an elongated hole 16 provided in the lower surface and long in the X direction so as to adjustably support the actuator base 15 in the tangential direction Ta.
b and the actuator base 1 through the elongated hole 16b.
Screw 16 to be screwed into the screw hole 16e provided on the lower surface of
and c. Furthermore, the pickup base 16
Is a laser diode 19, a beam splitter 20,
A rising mirror 21 and a photodiode 22 are provided.

Optical pickup 10 according to an embodiment of the present invention
Is configured as described above, and the laser diode 1
The light emitted from 9 is reflected by the beam splitter 20, then further reflected by the rising mirror 21, and is focused on the signal surface of the optical disc D (see FIG. 2) via the objective lens 11. Then, the light reflected by the signal surface of the optical disk is again passed through the objective lens 11 and the rising mirror 2
The light is reflected by the beam No. 1, transmitted through the beam splitter 20, and then enters the photodiode 22. As a result, the information recorded on the signal surface of the optical disc can be detected based on the output signal from the photodiode 22.

Here, the radial skew adjustment is performed as follows. First, the screw 15c is loosely tightened so that the damper base 13 can swing in the radial direction R with respect to the actuator base 15. Then, against the leaf spring 16d, the damper base 13 is swung about the screw 15c as the screw 15d advances and retreats. This allows the damper base 1
Radial skew adjustment of 3 is performed, then screw 15
By firmly tightening c, the damper base 13
Can be sandwiched between the rising portions 18a and 18b of the guide portion 18 and fixedly held. At this time, screw 15
The rotation of the head of c is not directly transmitted to the damper base 13 because the head is in contact with the rising portion 18a. Therefore, when tightening the screw 15c, the damper base 13 does not rotate together. Thus,
The skew adjustment of the damper base 4 can be accurately performed.

The tangential skew adjustment is
This is performed as follows. First, the screw 16c is loosely tightened so that the actuator base 15 can swing in the tangential direction Ta with respect to the pickup base 16 through the elongated hole 16b. And
The actuator base 15 is swung in the tangential direction with respect to the pickup base 16 along the support portion 16a. Thereby, the tangential skew adjustment of the actuator base 15 is performed. At this time, the screw 16c can move in the X direction within the elongated hole 16b. Then, by tightening the screw 16c firmly, the actuator base 15 can be fixedly held to the pickup base 16.

[0025]

As described above, according to the present invention, the damper base is fixed and held to the actuator base by tightening the tightening screw after the damper base is subjected to the radial skew adjustment with respect to the actuator base. Will be done. At that time, the damper base is
By being clamped by the guide part by tightening the tightening screw, it is fixed and held, so that the rotation of the tightening screw is not directly transmitted to the damper base, but by tightening the tightening screw, The damper base never rotates together.

Therefore, the radial skew adjustment of the damper base does not shift due to the tightening of the tightening screw, and the accurate radial skew adjustment can be performed.

Thus, according to the present invention, it is possible to provide a skew adjusting mechanism for an optical pickup in which co-rotation at the time of fixing the damper base can be prevented so that accurate radial skew adjustment can be performed. It will be.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing the configuration of an embodiment of an optical pickup according to the present invention.

FIG. 2 is a schematic sectional view of the optical pickup of FIG.

FIG. 3 is an exploded perspective view showing a configuration of an example of a conventional optical pickup.

FIG. 4 is a schematic sectional view of the optical pickup of FIG.

[Explanation of symbols]

 10 Optical pickup 11 Objective lens 12 Lens holder 13 Damper base 14 Suspension spring 15 Actuator base 15c Tightening screw 16 Pickup base 17 Magnet 18 Guide part

Claims (2)

[Claims] 1. A light emitting section, an objective lens for condensing light from the light emitting section onto a signal surface of an optical disc, a light receiving section on which reflected light from the signal surface of the optical disc enters through the objective lens, and an objective lens. An optical pickup including an actuator that supports the actuator so as to be movable in two axial directions, and a skew adjusting mechanism that attaches a damper base of the actuator to the actuator base so that the swing can be adjusted in the radial skew direction. The mechanism is composed of a guide portion integrally provided on the actuator base so as to sandwich the damper base so that the damper base can move smoothly, and a tightening screw for tightening the guide portions so as to approach each other. Yes, an optical pickup. 2. The optical pickup according to claim 1, wherein the inner diameter of the guide portion is slightly longer than the length of the damper base.