JPH0648538B2 - Pickup tilt adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a tilt angle adjusting device for an optical pickup that optically reads information recorded on a disc, for example.

(B) Conventional Technology In recent years, an optical disc reproducing apparatus such as a compact disc player for optically reading information recorded on a disc has been developed. A semiconductor laser is generally used as a light source in such a reproducing apparatus, and light emitted from the light source is irradiated onto a disk by an optical system having a collimator lens, a beam splitter, an objective lens, etc., and modulated by information recorded on the disc. The reflected light that is received and reflected is guided again by the optical system, and is received by the light receiving element to reproduce the information. Further, the light source, the optical system, the light receiving element and the like are housed in a pickup device, and by moving the pickup device in the radial direction of the disc, information of the entire area of the disc is reproduced.

In the disc reproducing apparatus, the reproduction characteristic is best when the optical axis of the beam incident on the disc is orthogonal to the disc surface, and therefore a device for adjusting the tilt angle of the pickup is required.

An example of such a tilt angle adjusting device is, for example, SAIkai 60-742.
The technique disclosed in Japanese Patent Publication No. 19 is known, but in such a conventional technique, it is necessary to provide a member for rotating the pickup device outside the pickup device body, which complicates the structure and reduces the number of parts. It has the disadvantage of increasing.

(C) Problems to be Solved by the Invention The present invention is to provide a tilt angle adjusting device capable of reliably adjusting the tilt angle of a pickup with a simple structure.

(D) Means for Solving the Problems The present invention is a device for adjusting the tilt angle of a pickup that slides along first and second guide rails that are arranged in parallel. A second hollow pipe having a relief portion is inserted into the eccentric first hollow pipe to form an interposition member for adjusting the tilt angle, while the first and second hollow pipes are parallel to the pickup. A through hole is formed, the first guide rail is inserted into the first through hole, and the second hole is formed.
The second guide rail is inserted into the through hole through the insertion member.

(E) Operation The pickup is supported so as to be movable in the radial direction of the disc along the first and second guide rails, and when the first hollow pipe is further rotated, the second pickup of the first hollow pipe is moved. The pickup is second due to the eccentricity with respect to the guide rail shaft.
The guide rail is displaced with respect to the first guide rail to rotate about the first guide rail, and the tilt angle of the pickup is changed.

(F) The embodiment (1) is a pickup, which has first and second through holes perpendicular to the optical axis of the objective lens (2) and parallel to each other.
(3) and (4) are drilled. Reference numeral (5) is a first guide rail which is inserted into the first through hole (3). (6) is a second guide rail, which is arranged parallel to the first guide rail (5 ) and has a second through hole (4) through an insertion member (7 ).
Has been inserted into. Thus, the pickup (1) is movably supported in parallel with the guide rails (5) and (6).
A turntable (8) is arranged so that a line connecting the center of the turntable and the center of the objective lens (3) is parallel to the moving direction of the pickup (1). By arranging the turntable (8) in this way, the disc is placed on the turntable (8).
When the pickup is moved when (D) is placed, the optical axis of the objective lens (2) moves in the radial direction of the disc (D).

The tilt angle adjusting device for the pickup arranged as described above will be described in detail below.

The insertion member (7) is the first hollow pipe (9) and this hollow pipe.
It is composed of a second hollow pipe (10) inserted into (9) (see FIG. 2). The first hollow pipe (9) is provided with a through groove (9a) in the central circumferential direction,
(9b) is open. Further, a flange portion (9c) is provided at one end, and a protrusion portion (9b) is provided on the flange portion (9c). Further, the first hollow pipe (9) is formed such that the hollow portion (9b) is eccentric to the outer circumference.

On the other hand, the second hollow pipe (10) has a collar portion (10a) at one end, and the hollow portion (10c) is opened by the relief portion (10b) provided at the end portion on the side of the collar portion (10a). There is.

As shown in FIG. 3, the pickup (1) first has the second through hole (4).
The first hollow pipe (9) is inserted into the first hollow pipe (9), the second hollow pipe (10) is then inserted into the hollow portion (9b) of the first hollow pipe (9), and the second hollow pipe (9) By inserting the second guide rail (6) from the relief portion (10b) of
Supported by the guide rails (6). Also pickup (1)
The insertion member (7) is temporarily fixed by pressing the second hollow pipe (10) with the screw (11) through the through groove (9a ) of the first hollow pipe (9).

It is now assumed that the pickup (1), the insertion member (7) , and the second guide rail (6) are in the state shown in FIG. 4 (a). At this time, the distance between the axis of the second guide rail (6) and the end surface of the pickup (1) is L. The first hollow pipe in this state
When (9) is rotated clockwise in the second through hole (4) of the pickup (1) (see FIG. 4 (b)), the hollow portion (9b) of the first hollow pipe (9) is ) Is eccentric with respect to the outer circumference, the distance L'between the axis of the second guide rail (6) and the end face of the pickup (1) is smaller than L. If the second guide rail (6) is fixed, the difference between the distances L and L'must be compensated by the movement of the pickup (1), i.e. the first hollow pipe (9). When it is rotated clockwise, the pickup (1) is urged to move in the arrow T direction with respect to the second guide rail (6).

Thus, when the pickup (1) is biased in the direction of the arrow T with respect to the second guide rail (6), the pickup (1) moves to the first direction.
Since it is also supported by the guide rails (5) of
Rotate clockwise with respect to the guide rail (5) of the
(See Figures (a) and (b)).

When the pickup (1) rotates clockwise, the second guide rail (6) is displaced in the second through hole (4) of the pickup (1), but the second hollow pipe (10) As the second guide rail (6) rotates and moves in the relief portion (10b), the positional deviation is absorbed.

On the other hand, when the first hollow pipe (9) is rotated counterclockwise, the pickup (1) rotates counterclockwise for the same reason as above.

As described above, in the present invention, the pickup can be rotated only by rotating the second hollow pipe, and the optical axis of the beam emitted from the pickup can be easily adjusted.

(G) Effect of the Invention The present invention is a device for adjusting the inclination angle of a pickup that slides along first and second guide rails that are arranged in parallel, and the first inner circumference is eccentric with respect to the outer circumference. A second hollow pipe having a relief portion is inserted into the hollow pipe of No. 3 to form an insertion member for adjusting the tilt angle, while the pickup is provided with first and second through holes in parallel therewith. Then, the first guide rail is inserted into the first through hole and the second guide rail is inserted.
Since the second guide rail is inserted into the through hole via the interposition member, the structure is extremely simplified, the number of parts is reduced, and the device can be downsized. Further, the tilt angle of the pickup can be adjusted simply by rotating the first hollow pipe, which simplifies the operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 5 are views showing an embodiment of the present invention. 1 (a) is a plan view showing a support state of the pickup, FIG. 1 (b) is a side view of the same, FIG. 2 is a view showing an insertion member, and FIG. 3 is a pickup, an insertion member, and a second guide. 4 (a) and 4 (b) are views showing the operation of the insertion member, and FIGS. 5 (a) and 5 (b) are views showing tilt angle adjustment of the pickup. (1) …… Pickup, (3) …… First through hole, (4) …… Second through hole, (5) …… First guide rail, (6) …… Second guide rail , (7) ...... Insert member, (9) ...... First hollow pipe, (10) ...... Second hollow pipe, (D) ...... Disc.

Claims (1)

[Claims] 1. A device for adjusting a tilt angle of a pickup that slides along first and second guide rails arranged in parallel, wherein a first hollow pipe whose inner circumference is eccentric with respect to an outer circumference. And a second hollow pipe having a relief portion is inserted into and formed with an insertion member for adjusting the tilt angle, while the pickup is provided with first and second through holes in parallel, An inclination adjusting device for a pickup, characterized in that the first guide rail is inserted into one through hole and the second guide rail is inserted into the second through hole through the interposing member.