JPS6146895B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor laser light source device for an optical information recording/reproducing device that allows easy adjustment of the angle and position of a semiconductor laser.

Semiconductor lasers are extremely small and lightweight, so when applied to light sources such as optical video disk devices, they have great potential for miniaturizing devices. However, since semiconductor laser chips are extremely small, they cannot always be mounted on heat sinks at precise angles and positions, requiring full adjustment of angle and position. Previously, a combination of a two-dimensional fine movement device and a two-dimensional rotary table was used, which was complex and had play in each axis, making it difficult to achieve high accuracy.

The present invention was made in order to eliminate the drawbacks of the conventional ones as described above, and by utilizing the bending of the structure instead of sliding for fine adjustment,
The object of the present invention is to provide a semiconductor laser light source device consisting of a single heat sink that has no backlash, is easy to process, and has full tonality in angle and position.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, 11 is a semiconductor laser light source, 12 is a collimating lens that converts a diverging laser beam into a flat beam, and 13 converts a parallel beam into 1 or 2 beams.
An objective lens focusing to a diameter of microns, 14 an information disk having a reflective surface recorded with a structure that can be read as a light source, 15 a motor for rotating the information disk 14, and 16 a reflective laser modulated by the information disk 14. A beam splitter that separates light, 17 a photodetector, 18 a semiconductor laser light source 1
1. A lens barrel that houses the objective lens 13 and the like.

FIG. 2 is a diagram showing details of the semiconductor laser light source 11. In the figure, 21 is a semiconductor laser (either in a package or a chip is possible), and 22 is a heat sink to which the semiconductor laser 21 is attached. be. This heat sink 2
2 is composed of three parts, an inner circumference A, a center B, and an outer circumference C, as shown in the figure. They are connected by a first channel 31 and a second channel 32. Further, the inner peripheral part A is pushed from the central part B by the first screws 33 and 34, and the central part B is pushed from the outer peripheral part C.
It is configured to be pushed by third screws 35 and 36 from above.

The operation of the apparatus of the present invention will be explained in detail below. The light emitted from the semiconductor laser light source 11 is turned into a parallel beam by the collimating lens 12, and is then transformed into a parallel beam by the objective lens 13.
The aperture of the beam is completely filled. Numerical aperture NA (numerical aperture) of objective lens 13
By choosing a suitable value (typically 0.5), the incident light can be projected onto the surface of the information disk 14 as a light spot with a diameter of 1 to 2 μm. Information such as video and sound is recorded on the surface of the information disk 14 in a circular or spiral shape using optically readable structural structures (for example, rows of pits, rows of bright and dark holes, etc.). is modulated by this information. The information is received by the objective lens 13, guided to the photodetector 17 by the beam splitter 16, and then passed through a suitable signal demodulation circuit (not shown) to reproduce the information. Information disk 14 is motor 15
It rotates by. During rotation, a focusing device and a track tracking device (not shown) are required to correctly form a light spot on the surface of the information disk 14, which is prone to surface wobbling or eccentricity, and to align it with the center of the track (row of pits). is necessary. Since these are not directly related to the present invention, they will be omitted here, but many known means can be used.

The traveling direction of the laser light emitted from the semiconductor laser 21 is not necessarily perpendicular to the plane of the inner peripheral portion A of the heat sink 22, but is often inclined by several degrees. This is because a packaged semiconductor laser already has an angular error when the semiconductor laser chip is soldered to the package, and when the semiconductor laser chip is soldered directly to the inner circumference A, there is an angle error. This is because there is an angular error. Regarding the positional error, the semiconductor laser is installed so that the emitting part is exactly in the center of the heat sink 22, but the error is several tens to several tens.
An error of 100 μm remains. In other words, as with the angle, the accuracy of soldering the chip to the package cage,
Furthermore, there is a limit to the accuracy with which the chip can be soldered to the center of the heat sink 22. However, according to the present invention, by finely adjusting the angle and position errors by deforming the channel inside the heat sink, the heat sink 22 is made into a semiconductor laser light source device in which the angle and center position of the attached semiconductor laser can be adjusted as a whole. I can do it.

First, angle adjustment will be explained. In order to minutely adjust the rotational angle around the Y-axis in the radiation direction of the semiconductor laser, grasp the inner peripheral part A and twist it to apply a rotational force around the Y-axis by the required angle. Physical twisting deformation occurs in the portion 31 to adjust the angle. Next, in order to adjust the angle around the X-axis, all you have to do is grab the center part B and twist it to give it rotation around the X-axis.Doing this will cause torsional deformation in the second channel 32. The required slope can be obtained. By the above two-dimensional angle adjustment, the inner peripheral part A where the semiconductor laser is attached is
This means that all angles have been adjusted with respect to the outer circumferential portion C.

Next, the principle of position adjustment will be explained. To adjust the position in the X-axis direction, push and pull the first screws 33 and 34 to bend the first channel 31 in the XY plane. To adjust in the Y-axis direction, push and pull the second screws 33 and 34 and bend the second channel 32 for adjustment. In any case, the angle adjustment made earlier is a minute angle, so there is virtually no possibility that the screw contact surface is tilted and cannot be pushed or pulled.

The angle and position adjustment described above can of course be performed using a microscope or the like using the outer circle of the outer circumferential portion C as a reference, so after the adjustment is completed, by fitting this outer circle portion to the optical system, This eliminates the need for troublesome adjustments after installation, making it extremely effective in simplifying the optical system of optical information recording and reproducing devices such as video discs. In particular, for a small-sized reading pick-up in which the semiconductor laser light source 11, collimating lens 12, beam splitter 13, and objective lens 13 are housed in one cylinder, as illustrated in FIG.
Since lenses and beam splitters can originally be operated by being attached to a cylinder with mechanical precision, the fact that the remaining semiconductor laser light sources can now be attached without adjustment according to the present invention is due to the adjustment-free assembly of the pick-up. This means that it can be done, and the practical effect is great.

Note that the shape of the outer surface of the outer peripheral portion C is not limited to a circle, and may of course be square or the like depending on the shape of the attachment portion.

Further, the material of the heat sink 22 may be metal or plastic having high thermal conductivity. In the case of plastic, it is preferable to apply metal plating to the surface on which the semiconductor laser is mounted.

In addition, the heat dissipation path generated from the semiconductor laser is narrow at the first channel and the second channel, resulting in poor heat dissipation. The gap in the outer periphery C can be filled with plastic, paste, etc. with good thermal conductivity.

FIG. 3 shows another embodiment of the invention. What is different from the embodiment shown in FIG. The point is that there are two symmetrically placed two on each side. According to this embodiment, the rotational adjustment around the X-axis and Y-axis can be performed with higher precision, and the reproducibility after adjustment is also good. However, position adjustment in the X and Y axis directions is omitted. Other than this point, the effects and application examples of this embodiment are similar to those of the embodiment shown in FIG.

As described above, according to the present invention, the semiconductor laser is configured so that it can be easily incorporated into an adjusted semiconductor laser light source assembly, so that it can be installed in an optical information recording/reproducing device, etc. without any adjustment, and the device This has the effect of achieving higher accuracy, simplification, and lower cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an optical information recording/reproducing apparatus equipped with a semiconductor laser light source device according to an embodiment of the present invention, FIGS. 2a and 2b are a plan view and a side view of the semiconductor laser light source device of FIG. Figures 3a and 3b are a plan view and a side view of another embodiment of the invention. 20... Semiconductor laser, 22... Heat sink, A
...Inner circumference part, B...Central part, C...Outer circumference part, 31...First
channel, 32...second channel, 33,
34...first screw, 35, 36...second screw.

Claims (1)

[Scope of Claims] 1. A semiconductor in an optical information recording/reproducing device that focuses laser light from a semiconductor laser with a lens, projects the light spot onto a disk on which information is recorded, detects the reflected light, and reproduces information. A laser light source device, which includes a semiconductor laser, an inner peripheral part provided in an XY plane and to which the semiconductor laser is mounted at the center, and a central part formed to surround this inner peripheral part in the same plane as the inner peripheral part. and an outer peripheral part formed to surround the central part in the same plane as the central part.
The central portion is connected to the peripheral portion so as to be twisted and deformable around the Y-axis and tiltable in the X-axis direction through a channel, and the central portion is twisted around the X-axis through a second channel located on the X-axis. 1. A semiconductor laser light source device for an optical information recording/reproducing device, comprising: a heat sink coupled to be deformable and tiltable in the Y-axis direction. 2. A first screw provided in the central portion facing each other on the X-axis and abutting against a side surface of the inner peripheral portion to tilt the inner peripheral portion in the
Claim 1, further comprising second screws that are provided on the axis to face each other and abut against the side surface of the central portion to tilt the central portion in the Y-axis direction. A semiconductor laser light source device of the optical information recording/reproducing device described above.