JPH0773495A - Light source device - Google Patents

Abstract

PURPOSE:To easily and accurately fix a collimater lens of a light source device. CONSTITUTION:Plural elastic pressing pieces 26a arranged toward an optical axis one after another are provided projectingly on both end edges of the front and rear of a mirror barrel 26. When the mirror barrel 26 into which the collimater lens 25 is inserted and fixed is forcedly inserted into a cylindrical hole 23a of a housing 23 while bending the elastic pressing pieces 26a, the mirror barrel 26 comes into pressurized-contact with the inner peripheral wall of the cylindrical hole 23a by the elastic force of the elastic pressing pieces 26a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device used for an optical head of an optical disk device for recording / reproducing / erasing information on / from an optical disk.

[0002]

2. Description of the Related Art In recent years, as the capacity of information recording media has increased, attention has been paid to high density optical disks. An optical disk device is used for recording, reproducing, and erasing information on this type of optical disk, and an optical head using a semiconductor laser light source is used for the optical disk device. This optical head moves the radial direction of the optical disc to focus the objective lens on a predetermined track, and records or erases information thermally or magneto-optically by the spot light by the semiconductor laser formed on the track. Alternatively, information is reproduced by reflected light.

Light emitted from the semiconductor laser light source is used as a parallel light flux by a collimator lens. Therefore, it is necessary to adjust the focus of the collimator lens within a few μm with respect to the semiconductor laser light source and the angle of view adjustment to adjust the optical axis tilt of the emitted light. That is, in the focus adjustment, the collimator lens is installed movably in the optical axis direction with respect to the frame body to which the semiconductor laser light source is fixed, and the focus position is adjusted and then fixed. Further, in adjusting the angle of view, the frame body to which the semiconductor laser light source is fixed and the frame body to which the collimator lens is fixed are separately configured, and after the position of the semiconductor laser light source is adjusted to the optical axis of the collimator lens, both are adjusted. Bonded and fixed.

For example, as shown in FIG. 3, a holder 2 to which a semiconductor laser light source 1 is press-fitted and fixed is fixed to a housing 3 by a fixing screw 4, and a compression spring 5 is inserted into a cylindrical hole 3a of the housing 3 after the compression spring 5 is inserted. The collimator lens 6 is fitted and the adjusting screw 7 is screwed. A collar portion 7a, a screw portion 7b, and a tip portion 7c are formed on the adjusting screw 7, and the collimator lens 6 uses the compression spring 5 to adjust the adjusting screw 7.
Is pressed against the tip portion 7c of the. When adjusting the focus, the collar portion 7a is rotated to finely move the collimator lens 6 in the optical axis direction. After finishing the focus adjustment, the collimator lens 6 is fixed by an adhesive agent (not shown).

Further, as shown in FIG. 4, the holder 12 to which the semiconductor laser light source 11 is press-fitted and fixed is a housing 13.
Is fixed to the collimator lens 15 by a fixing screw 14.
After being fixed in the lens barrel 16, the lens barrel 16 is press-fitted and fixed in the cylindrical hole 13 a of the housing 13.

[0006]

However, in the conventional example shown in FIG. 3 described above, when the gap between the outer peripheral surface of the collimator lens 6 and the inner peripheral surface of the cylindrical hole 3a becomes large, the optical axis of the collimator lens 6 tilts. Therefore, it is necessary to process both of them with high accuracy. Further, in order to finely move the collimator lens 6 with high accuracy, the screw portion 7b of the adjusting screw 7 must be processed to have a particularly fine pitch. Further, since the collimator lens 6 is only pressed to the adjusting screw 7 side by the compression spring 5, there is a problem that the focus fluctuates during the process of hardening the adhesive.

On the other hand, in the conventional example shown in FIG.
Since 6 is only press-fitted in the cylindrical hole 13a, when the processing accuracy of the lens barrel 16 and the cylindrical hole 13a is poor, a high press-fitting force is required to fit them, or However, there is a problem that the optical axis is tilted due to the large gap.

An object of the present invention is to solve the above-mentioned problems and to provide a light source device capable of easily adjusting a collimator lens with high accuracy.

[0009]

A light source device according to the present invention for achieving the above object is a light source device in which a collimator lens is fixed in a lens barrel and the lens barrel is press-fitted and fixed in a cylindrical hole of a housing. In the above, in the lens barrel, a plurality of elastic pressing pieces for pressing the peripheral wall of the cylindrical hole are provided.

[0010]

In the above-described light source device, the collimator lens is fixed in the lens barrel having the elastic pressing piece, and the lens barrel is press-fitted into the cylindrical hole while bending the elastic pressing piece, so that the elastic pressing piece is tubular. The lens barrel is fixed by pressing it into the hole.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. 1 is a partial sectional view, and FIG. 2 is an exploded perspective view. The semiconductor laser light source 21 is press-fitted and fixed to a holder 22, and the holder 22 is fixed to a housing 23 with a screw 24. A cylindrical hole 23a is provided in the housing 23, and the collimator lens 25 is provided in the cylindrical hole 23a.
The lens barrel 26 fitted and fixed to is fixed by press fitting. Lens barrel 2
6, a plurality of elastic pressing pieces 2 are provided on both front and rear edges.
6a are projected at equal intervals. Before being fitted into the cylindrical hole 23a, these elastic pressing pieces 26a are expanded to the outside slightly larger than the inner diameter of the cylindrical hole 23a.

When the lens barrel 26 is press-fitted and fixed in the cylindrical hole 23a, the elastic pressing pieces 26a are bent to press them into the cylindrical hole 23a, and further the entire lens barrel 26 is cylindrical-shaped hole 23a.
Push it in. At this time, the elastic pressing piece 26 has the cylindrical hole 23.
The lens barrel 26 is pressed against the inner wall surface of a and is fixed in the cylindrical hole 23a by the elastic force of the elastic pressing piece 26a.

In this embodiment, even when the lens barrel 26 is molded from synthetic resin or the like and the expansion coefficients of the housing 23 and the lens barrel 26 are different, the elastic pressing piece 26a has the collimator lens 25.
Since it is provided before and after, the focus does not change.

An adhesive may be applied between the lens barrel 26 and the housing 23.

[0015]

As described above, in the light source device according to the present invention, since the lens barrel to which the collimator lens is fitted and fixed is fixed to the cylindrical hole by the pressing force of the elastic pressing piece, the processing of the lens barrel and the cylindrical hole is performed. Even if the accuracy is poor, the elastic pressing piece can be elastically deformed to fix the collimator lens with a constant pressing force. Further, since it is not necessary to process the lens barrel with high precision, the cost can be reduced and the workability can be improved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an embodiment.

FIG. 2 is an exploded perspective view.

FIG. 3 is a partial cross-sectional view of a conventional example.

FIG. 4 is a partial cross-sectional view of a conventional example.

[Explanation of symbols]

 23 housing 25 collimator lens 26 lens barrel 26a elastic pressing piece

Claims (3)

[Claims] 1. A light source device in which a collimator lens is fixed in a lens barrel and the lens barrel is press-fitted and fixed in a cylindrical hole of a housing, and a plurality of elastic pressing members for pressing the peripheral wall of the cylindrical hole to the lens barrel. A light source device characterized in that a piece is provided. 2. The light source device according to claim 1, wherein the elastic pressing pieces are formed on both front and rear edges of the lens barrel. 3. The light source device according to claim 1, wherein the lens barrel is molded from synthetic resin.