JPH064874A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a light source device adjustable so as to make the optical axis of a collimate lens coincide with the outgoing direction of the laser beam of a semiconductor laser. CONSTITUTION:The light source device whose light source holder 15 is a nearly semispherical shape having a spherical surface around the light emitting point 13 of the semiconductor laser 1 and inserted into the recessed part of the semispherical shape having the same curvature as the spherical surface that a holding member 16 has and supported rockingly. Then, by moving the position of an adjusting hole 22 provided on the light source holder 15 by an adjusting member 21 inserted from an adjusting member hole 23 being a penetration hole provided on the holding member 16, the inclination of the semiconductor laser 1 is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing device using a semiconductor laser, and more particularly to a light source device provided therein.

[0002]

2. Description of the Related Art Since a semiconductor laser is extremely small and light, when it is applied to a light source such as an optical information recording / reproducing device, it exerts great power for downsizing the device. However, since the chip of the semiconductor laser is extremely small, it is not always attached to the light source holder at an accurate angle and position and supported by the holding member.

In order to solve such a problem,
There is a technique described in JP-A-57-33445. In this technology, a semiconductor laser chip is mounted on a hemispherical light source holder, and this hemispherical holder is fitted into a holding member having a spherical recess having the same curvature as that of the semiconductor laser chip, thereby making it possible to adjust the angle of the semiconductor laser. It was done. Furthermore, a structure is also disclosed in which the emission point of the semiconductor laser is designed to coincide with the center of the spherical surface of the hemispherical holder so that the position of the emission point does not deviate from the optical axis.

[0004]

As described in the prior art, the use of the semiconductor laser has been a great force for downsizing the device. However, since the semiconductor laser chip is extremely small, it is not always mounted at the correct angle and position. Ideally, it is ideal that the light emitting point of the light source is located on the optical axis of the collimator lens, and the vector of the direction of the optical axis and the direction of the emitted light of the semiconductor laser that is the light source are the same. However, in reality, the direction of the emitted light of the semiconductor laser is often inclined by 1 to several degrees with respect to the optical axis due to a problem such as mounting error.

What has been made in view of such problems is as follows.
This is the technique described in JP-A-57-33445. This technique makes it possible to easily adjust the position of the semiconductor laser. However, the position adjustment of the semiconductor laser is a fine adjustment within a range of 1 degree to several degrees, and a specific structure or adjustment method therefor is not clearly disclosed in JP-A-57-33445.

An object of the present invention is to solve the above problems and provide an optical recording / reproducing apparatus having a light source device which has established a method for adjusting the position of a semiconductor laser.

[0007]

In order to achieve such an object, the present invention provides a light source such as a semiconductor laser, a plane on which the light source is mounted, and a substantially hemisphere having a spherical surface centered on a light emitting point of the light source. -Shaped light source holder, a holding member having a spherical recess into which the spherical surface of the light source holder is slidably fitted,
Information obtained by irradiating an information recording medium with a light beam spot, which includes a light source device including a lens that collimates laser light generated by the light source, and an objective lens that condenses parallel light emitted from the light source device. In an optical recording / reproducing apparatus for recording, reproducing or erasing, the at least one recess or groove formed in the spherical surface of the light source holder and the spherical recess of the holding member facing the recess or groove. And an adjusting member that is inserted into the through hole and has a tip inserted into the recess or groove, and operates the adjusting member to change the relative position of the light source holder with respect to the holding member. The configuration is such that the direction of light from the light source is adjusted.

[0008]

According to the present invention, a hemispherical light source holder equipped with a light source such as a semiconductor laser is swingably fitted in a recess having the same curvature as that of the light source holder of the holding member, and is held in an adjustment hole of the light source holder. Fine adjustment is possible by bringing the tip of the shaft-shaped adjusting member into contact with the adjusting hole which is a through hole slightly larger than the adjusting hole provided in the member and moving the adjusting hole.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the basic structure of an optical recording / reproducing apparatus. 1 is a semiconductor laser which is a light source, 2 is a collimating lens, 3 is a beam splitter, 4 is a quarter wavelength plate, and 5 is an objective. Lens, 6 recording medium, 7 condenser lens, 8 knife edge prism, 9 first light receiving element,
Reference numeral 10 is a second light receiving element, 11 is a reflecting prism, and 12 is an objective lens actuator.

The laser light generated by the semiconductor laser 1 becomes parallel light by the collimator lens 2, passes through the beam splitter 3 and the quarter wavelength plate 4, and enters the objective lens 5 by the reflection prism 11. The objective lens 5 collects the guided parallel light and forms a beam spot on the recording medium 6.
Then, the reflected light from the recording medium 6 passes through the objective lens 5 and the quarter-wave plate 4 again, is reflected by the beam splitter 3, and is guided to the condenser lens 7. The condenser lens 7 condenses the reflected light, and the collected light is partially divided by the knife edge prism 8 to form a beam spot of the first light receiving element 9,
The other light becomes a beam spot with which the second light receiving element 10 is directly irradiated. The output of the first light receiving element 9 is used for tracking servo, the second light receiving element 10 is used for focusing servo, and the objective lens actuator 12 is driven according to the outputs of the light receiving elements 9, 10.

Next, a light source device for irradiating the beam splitter 3 with parallel light will be described. FIG. 2 shows a light source device according to the first embodiment, in which 13 is a light emitting point, 14 is a lens cell, 15 is a light source holder, 16 is a holding member, 17 is a set screw, 18 is a spring, and 19 is A housing fixing screw, 20 is a lens set screw, 21 is an adjusting member, 22 is an adjusting hole, 23 is an adjusting member hole, 24 is a pickup housing, and 25 is an arm.

One surface of the light source holder 15 is a flat surface on which the semiconductor laser 1 is mounted. The other surface of one light source holder 15 is a spherical surface, and the adjustment hole 22 is formed on the spherical surface. That is, the light source holder 15 has a hemispherical shape, and a mounting portion (not shown) of the semiconductor laser 1 is formed on a plane so that the light emitting point 13 of the semiconductor laser 1 is located at the center of the hemisphere. The light source holder 15 thus configured is held by the cylindrical holding member 16 having a bottom. Holding member
The bottom of 16 is a hemispherical recess, and its curvature is the same as the spherical surface of the light source holder 15. The light source holder 15 is swingably fitted and held in the recess of the holding member 16. Light source holder
An adjusting member hole 23, which is a through hole slightly larger than the adjusting hole 22, is formed in the concave portion of the holding member 16 facing the adjusting hole 22 of the spherical surface. In the opening of the holding member 16, the lens cell 14
The collimator lens 2 housed in is provided. The lens cell 14 can slide the opening of the holding member 16 in the direction of arrow A in the figure, adjusts parallel light, and sets the lens set screw 20.
Fixed by. The holding member 16 has arms 25, 25 extending laterally.
Housing fixing screws 19, 19 via arms 25, 25
It is fixed to the pickup housing 24 with. Adjustment member 21
Is a member for adjusting the inclination of the semiconductor laser 1 with respect to the optical axis and the laser light emitting direction. Specifically, as shown in FIG. 3, the adjustment member 21 is inserted through the adjustment member hole 23, the tip is brought into contact with the adjustment hole 22, and the light source holder 15 is slid in the concave portion of the holding member 16, so that the tilt Adjust. After adjusting the inclination, it is fixed by the set screw 17 via the spring 18 or by injecting an adhesive from the adjusting member hole 23 and fixing.

Next, a light source device according to the second embodiment will be described with reference to FIGS. In the second embodiment, the adjustment member 21, the adjustment hole 22, and the adjustment member hole 23 in the first embodiment are improved, respectively.
This will be specifically described.

In FIG. 4, 26 is an eccentric pin, 27 is an adjusting groove, and 28 is an adjusting rod which is an adjusting member. On the spherical surface of the light source holder 15, the adjusting groove 27 in the vertical direction and the adjusting groove 27 in the horizontal direction are provided. Two adjusting grooves 27, 27 of the adjusting groove 27 are provided. An adjusting member hole 23, which is a through hole, is provided in the surface of the concave portion of the holding member 16 where the adjusting grooves 27, 27 face each other, and has a size such that the adjusting rod 28 can be loosely inserted therein. As shown in FIG. 5, the adjusting rod 28 is composed of a columnar shaft, and an eccentric pin 26 is provided at a position on the tip end surface thereof which is deviated from the central axis of the columnar shaft.

When the adjusting rods 28, 28 thus constructed are inserted into the adjusting member holes 23, 23, the eccentric pins 26, 26 are adjusted at the same time.
Insert at 27 and 27. Then, by rotating the adjusting rods 28, 28, the eccentric pin 26 comes into contact with the adjusting groove 27, the light source holder 15 is swung, and the inclination of the collimator lens 2 with respect to the optical axis is adjusted.

Next, a light source device according to the third embodiment will be described with reference to FIG. In the second embodiment,
In contrast to performing the tilt adjustment by rotating the adjusting member 21 about the central axis, the third embodiment applies the lever principle to perform the tilt adjustment. The configuration will be described below. .

As shown in FIG. 6, in the third embodiment, the first
In the configuration of the above embodiment, a spherical fulcrum portion 29 is provided in a portion of the adjusting member 21 where the adjusting member hole 23 is located, and is sandwiched or brought close to the adjusting member hole 23.

That is, a fulcrum 29 having a spherical fulcrum, one end of the adjusting member 21 whose point of action is in contact with the adjusting hole 22, the other end of the adjusting member 21 with a force point, and the other end of the adjusting member 21 being swung. Thereby, the light source holder 15 is swung to adjust the inclination.

The light source device configured as described above is fixed to the pickup housing 24 with the housing fixing screw 19 via the arm 25 as shown in FIG. At that time, arm 25
The arm 25 is slid on the basis of the plane in contact with the pickup housing 24 so that the light emitting point 13 of the semiconductor laser 1 is positioned on the optical axis of the collimating lens 2 and then the housing fixing screw. Fix with.

[0021]

The present invention has the following effects due to the above configuration. First, a hemispherical light source holder equipped with a light source is supported by fitting it in a hemispherical recess having the same curvature as the spherical shape of the light source holder of the holding member so that the light emitting point is located at the center. Since at least one recess is provided in the adjusting member, the adjusting member is inserted into the adjusting member hole provided in the holding member, and the position of the light source and the holding member are adjusted by operating the adjusting member, the position of the light emitting point does not shift. In addition, the inclination with respect to the optical axis can be easily adjusted. Furthermore, adjustment from the outside of the light source device is possible, and fine adjustment is possible by changing the thickness and shape of the adjusting member used. Therefore, it is possible to provide an optical recording / reproducing apparatus that maintains a sufficient optical axis tilt adjustment accuracy and performs stable recording, reproduction and erasing.

Further, the adjusting rod is provided with an eccentric pin at the tip thereof, and when the adjusting rod is inserted into the adjusting member hole of the holding member, the eccentric pin is also loosely inserted into the groove provided in the light source holder at the same time. By rotating the eccentric pin, the eccentric pin abuts on the groove and swings the light source holder, so that a slight amount of tilt adjustment is possible.

Furthermore, in accordance with the principle of leverage, the adjusting member is supported in the holding member, and that point is used as a fulcrum, one end of the adjusting member that comes into contact with the adjusting hole of the light source holder is a working point, and the other end of the adjusting member is a force point. Since the position of the light source holder is adjusted by a simple operation, a slight amount of tilt adjustment can be performed by a simple operation.

Further, by providing at least one flat surface on the holding member and supporting the holding member with the flat surface serving as a reference surface, the deviation between the optical axis and the light emitting point can be adjusted.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of an optical recording / reproducing apparatus.

FIG. 2 is a diagram showing a cross section of the light source device of the optical recording / reproducing apparatus according to the first embodiment of the present invention.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is a cross-sectional view of essential parts of a light source device of an optical recording / reproducing apparatus according to a second embodiment of the present invention.

5A and 5B are a front view and a perspective view of an adjusting member in the light source device of FIG.

FIG. 6 is a cross-sectional view of essential parts of a light source device of an optical recording / reproducing device according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser, 2 ... Collimating lens, 5 ... Objective lens, 6 ... Recording medium, 13 ... Emission point, 14 ... Lens cell, 15 ... Light source holder, 16 ... Holding member, 21 ... Adjusting member, 22 ... Adjusting hole, 23 ... adjusting member hole, 28 ... adjusting rod, 29 ... fulcrum part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Haruhiko Kono 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Masaki Sakata 10-3 Kitamura, Tottori, Tottori Ricoh Micro Electronics Co., Ltd. Within

Claims (4)

[Claims] 1. A light source such as a semiconductor laser, a substantially hemispherical light source holder having a flat surface on which the light source is mounted and a spherical surface centered on a light emitting point of the light source, and the spherical surface of the light source holder is slidably fitted. A light beam including a holding member having a spherical concave portion for converting the laser light generated by the light source into a parallel light beam, and an objective lens for collecting the parallel light emitted from the light source device. In an optical recording / reproducing apparatus for irradiating a spot on an information recording medium to record, reproduce or erase information, at least one recess or groove formed in the spherical surface of the light source holder and facing the recess or groove. The holding member includes: a through hole formed in a spherical concave portion of the holding member; and an adjusting member that is inserted into the through hole and has a tip inserted into the recess or groove. The holding member is operated by operating the adjusting member. Against Optical recording and reproducing apparatus characterized by changing the relative position of the light source holder, to adjust the direction of light from the light source. 2. The adjusting member is a cylindrical rod, and the eccentric pin provided at the tip of the adjusting rod is inserted into the groove of the light source holder, and the adjusting rod is rotated to change the relative position of the light source holder. The optical recording / reproducing apparatus according to claim 1, wherein 3. The adjusting member has a fulcrum portion having a large diameter in a portion located in a through hole formed in the holding member, and the adjusting member is swung about the fulcrum portion to allow relative movement of the light source holder. The optical recording / reproducing apparatus according to claim 1, wherein the target position is changed. 4. The optical recording / reproducing apparatus according to claim 1, wherein the holding member has at least one reference flat surface, and the flat surface is fixed to the housing to hold the light source device.