JPH0777030B2 - Fixing device for semiconductor laser - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an optical disk device, a digital audio device, etc. for recording / reproducing information on / from a disk by using a semiconductor laser as a light source to narrow this laser light into a minute light on the disk. The present invention relates to a semiconductor laser fixing device.

2. Description of the Related Art In recent years, optical disk devices have been attracting attention from various aspects as next-generation information storage devices due to their large storage capacity, high-speed random access function, etc., and some have already been put to practical use.

An example of the conventional semiconductor laser fixing device described above will be described below with reference to the drawings.

5 and 6 show an example of a conventional fixing device, FIG. 5 is an exploded view thereof, and FIG. 6 is a sectional view thereof. 1 is a semiconductor laser having a round stem 5, 2
Is a laser holder for accommodating this semiconductor laser, which fixes the semiconductor laser 1 by a leaf spring described later. 3 is a leaf spring that presses and fixes the semiconductor laser 1 on the laser holder 2 in the optical axis direction by its spring property, and presses and fixes the round stem portion 5 of the semiconductor laser 1.

FIG. 7 is a diagram for briefly explaining an incident system to a disc in an optical system for an optical disc device using the semiconductor laser 1, and 6 is a collimating lens for converting divergent light of the semiconductor laser 1 into parallel light. Reference numeral 7 is an objective lens for narrowing this parallel laser light onto the disc, and 8 is a disc.

Problems to be Solved by the Invention Generally, in an optical disk device, it is necessary to accurately follow a track with a laser beam that is focused by an objective lens 7 with respect to surface wobbling or eccentricity due to rotation of the disk. The depth of focus of the objective lens 7 is approximately ± 1.
On the other hand, the laser beam is controlled to follow the surface deflection of the disk 8 within ± 1 μm in the focusing direction. Therefore, the margin for stabilizing the servo is very small in terms of the depth of focus, and in order to obtain a high S / N ratio, the objective lens 7
Therefore, the beam focused on the disk 8 is required to be stable with good aberrations. For this purpose, it is necessary that the incident light on the objective lens 7 is vertical and parallel light in any state, and especially if there is a change in the ambient environment (temperature), a simple linear expansion of the material causes As shown in FIG. 5A, when the temperature becomes high, the distance between the semiconductor laser 1 and the collimator lens 6 changes, and the laser light exiting the collimator lens 6 becomes convergent light, and the performance of the objective lens 7 is not utilized, and the image forming beam includes aberration. The depth of focus becomes shallower. On the other hand, as shown in FIG. 8b, when the temperature becomes low, the light emitted from the collimator lens 6 becomes divergent light and the image formation state of the beam similarly deteriorates. As described above, in these optical disc devices, maintaining the optimum positional relationship between the semiconductor laser 1 and the collimator lens 6 is particularly important for stabilizing the image forming beam, in order to stabilize the entire system. Become. In addition to the above-described change in the distance between the optical axes of the semiconductor laser 1 and the collimator lens 6 due to the change in ambient temperature, a problem remains. Due to the same change, in the semiconductor laser fixing device shown in the conventional example, the round stem portion 5 of the semiconductor laser 1 slightly rotates in the laser holder 2 due to the change in the hole size of the laser holder 2 which houses the round stem portion 5. Alternatively, there is a risk of movement, and in this case, as shown in FIG. 9, the incident light on the objective lens 7 becomes obliquely incident, which deteriorates the beam image formation state and causes an unstable factor in focus servo. Also, if the semiconductor laser 1 rotates or moves, the positional relationship is not guaranteed to return to its original state even if the ambient temperature returns to the original state, and as a result, it changes even if the initial image forming beam state returns to room temperature. This will have a great impact on the stability of the entire system.

Means for Solving the Problems In order to solve the above problems, a semiconductor laser fixing device according to the present invention is a laser holder for accommodating and holding a semiconductor laser having a round stem, and the semiconductor laser is the laser holder. A fixing device for a semiconductor laser comprising a leaf spring for pressing and fixing from the same direction as the optical axis direction of the laser, in the laser holder which is a surface for accommodating and holding the round stem of the semiconductor laser. The peripheral surface is provided with locking portions for supporting the round stem of the semiconductor laser at two positions in a direction perpendicular to the optical axis direction of the laser, and the round stem of the semiconductor laser is locked. It is characterized in that it is provided with means for pressing and fixing to the section.

Action Since the semiconductor laser is pressed and fixed in a fixed direction in the housing hole of the laser holder by the leaf spring, the semiconductor laser 1 does not rotate even if the ambient temperature changes, and therefore the position itself of the semiconductor laser 1 changes. Even if the ambient temperature returns to the original value, the position of the semiconductor laser 1 is also returned, and a stable imaging beam can be obtained on the disk.

EXAMPLES Hereinafter, a semiconductor laser fixing device according to an example of the present invention will be described with reference to the drawings.

1 to 4 show the structure of a semiconductor laser fixing device according to the first embodiment of the present invention. FIG. 1 shows an exploded perspective view thereof, and FIG. 2 shows a storage state of the semiconductor laser. , Fig. 3 is a state diagram in which the leaf spring is removed from Fig. 2, Fig. 4
The figure shows an AA cross section in FIG.

10a and 10b are the inner peripheral surface of the laser holder 2 which is a surface for accommodating and holding the round stem portion 5 of the semiconductor laser 1, and the round stem portion 5 of the semiconductor laser 1 is perpendicular to the optical axis direction of the laser. Locking parts for supporting in two places, 11a, 11
b and 11c are claws provided on the leaf spring 3, of which 11a is provided at a portion corresponding to a position opposite to the engaging portions 10a and 10b as shown in FIG. And has a flat portion having a predetermined angle. The flat portion is brought into contact with the round stem portion 5 of the semiconductor laser 1 as shown in FIG.
The elastic force of the claw 11a acts in the arrow direction 13 in FIG.
On the other hand, 11b and 11c are partially bent to press the stem portion 5 in the optical axis direction 14. Other than this, the configuration is the same as that shown in the conventional example shown in FIG.

The fixing device of the fixing portion of the semiconductor laser configured as described above will be described. First, the leaf spring claw 11a is first attached to the semiconductor laser 1 placed on the locking portions 10a, 10b of the holes of the laser holder 2. The semiconductor laser 1 is fixed to the laser holder 2 by tightening the screw 12a so that it acts in the arrow direction 13 and then tightening the remaining screws 12b sequentially. As described above, in the present embodiment, the flat plate claw portion 11a of the leaf spring is provided in a part of the leaf spring 3 corresponding to the position opposite to the laser holder locking portions 10a and 10b at a predetermined angle with respect to the optical axis direction of the laser. The semiconductor laser 1 is provided with a claw 11a having a flat surface, and the flat surface of the claw 11a is brought into contact with the round stem portion 5 of the semiconductor laser 1 and the elastic force of the claw 11a cooperates with the locking portions 10a and 10b. The circular-shaped stem portion 5 is sandwiched, and the stem portion is pressed in the direction of arrow 13 in FIG. 3 by acting before the other claws 11b and 11c.
The stem portion 5 is pressed and fixed in the optical axis direction 14 by c.

FIG. 10 shows a second embodiment of the present invention, in which a recess 14 is provided in the stem accommodating hole so as to obtain the same effect as that of the engaging portion in the first embodiment. FIG. 11 shows a third embodiment of the present invention in which a screw hole is provided in the laser holder 2 and the semiconductor laser stem portion is pressed by the screw 15 to the laser holder locking portion to be fixed. Similar effects can be obtained in these other embodiments.

EFFECTS OF THE INVENTION As described above, according to the present invention, the semiconductor laser round stem portion is provided on the inner peripheral surface of the laser holder, which is a surface not only for pressing and fixing the semiconductor laser in the optical axis direction but also for storing and holding the round stem portion. A locking part is provided to support the laser at two points in the direction perpendicular to the optical axis of the laser. The round stem of the semiconductor laser is pressed and fixed to this locking part, and the round stem is attached to each vertex of the triangle. Since the semiconductor laser is held in position, the rotation of the semiconductor laser does not fluctuate even if the ambient temperature changes. Is guaranteed to be completely restored, and a diaphragm beam on the disk that is stable against changes in the surrounding environment can be obtained.

[Brief description of drawings]

1 is an exploded perspective view of the first embodiment of the present invention, FIG. 2 is a front view of the same, FIG. 3 is a view showing a state in which a leaf spring is removed from FIG. 2, and FIG. Sectional view in the figure,
FIG. 5 is an exploded perspective view showing a conventional example, FIG. 6 is a sectional view of the same, FIG. 7 is an explanatory view showing a part of an optical system using a semiconductor laser, and FIG. FIG. 9 is an explanatory view showing a change in position of the semiconductor laser, FIG. 10 is a front view showing a second embodiment of the present invention, and FIG. 11 is a similar third embodiment. FIG. 1 ... Semiconductor laser, 2 ... Laser holder, 3 ...
… Leaf springs, 5 …… Round stems, 10a, 10b… Locking parts.

Claims (3)

[Claims] 1. A laser holder for accommodating and holding a semiconductor laser having a round stem, and a plate for pressing and fixing the semiconductor laser on the laser holder by sandwiching it from the same direction as the optical axis direction of the laser. A semiconductor laser fixing device comprising a spring, on the inner peripheral surface of the laser holder, which is a surface for housing and holding the round stem of the semiconductor laser, the round stem of the semiconductor laser in the optical axis direction of the laser. On the other hand, a locking portion is provided for supporting at two positions in the vertical direction, and means for pressing and fixing the round stem of the semiconductor laser to the locking portion is provided. Fixing device. 2. As means for pressing and fixing a round stem of a semiconductor laser to a locking portion, a part of a leaf spring corresponding to a position opposite to the locking portion is provided with respect to the optical axis direction of the laser. And a claw having a flat portion having a predetermined angle, the flat portion of the claw is brought into contact with the round stem of the semiconductor laser, and the elastic force of the claw cooperates with the locking portion to round the semiconductor laser. The apparatus for fixing a semiconductor laser according to claim 1, characterized in that the die stem is sandwiched. 3. A screw hole is provided in a laser holder as a means for pressing and fixing a round stem of a semiconductor laser to a locking portion, and the round stem of the semiconductor laser is directed toward the locking portion through this screw hole. The device for fixing a semiconductor laser according to claim 1, wherein the device is pushed in with a screw.