JPH04302486A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To design the longitudinal dimension of a light pickup part small, and enable the whole thinning of the system such as a optical disc, etc., by setting the chip junction face of a semiconductor laser vertically to the direction of the short side of an oblong fin. CONSTITUTION:The chip face junction face of a semiconductor laser is made vertical to the direction of the short side of an oblong fin. If one uses this semiconductor device, the short side direction of the fin 3 is arranged so that the spread direction of the light beam 9 may be the longitudinal direction 12 of a light pickup part. A spatial margin 13 occurs in the longitudinal direction 12 of the optical system in the light pickup part. Accordingly, thanks to this margin 13, the longitudinal 12 dimension can be designed small.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device used as a light source for optical information processing devices such as optical disks and magneto-optical disks.

0002

[Prior Art] Semiconductor laser devices (hereinafter abbreviated as LD) are widely used as light sources for optical information processing devices such as optical disks and magneto-optical disks.
During reading, a method is generally used in which a high-frequency current is superimposed on the LD drive current in order to reduce the unique noise caused by the return light from the disk.

In that case, a high-frequency module 2 (hereinafter referred to as the module), which contains a circuit that exclusively generates, amplifies, and superimposes high-frequency current, is housed in a shield case 4 (see FIG. 3).
D1 and a mounting fin 3 for mounting on an optical pickup are often integrated. Note that the shield case 4 is installed to shield unnecessary radiation generated when high-frequency current is superimposed. Since the fin 3 requires escape holes 5a to 5d for mounting screws, a rectangular shape is used as shown in FIG. 3. At this time, in the conventional technology, as shown in the figure, the long side direction of the fin 3 and the direction perpendicular to the bonding surface of the LD chip 6 (hereinafter referred to as θ perpendicular) are set in the same direction. many.

FIG. 4 shows a structure in which an optical semiconductor device having such a structure is attached to an optical pickup portion of an optical disk device or the like. In the optical pickup, in order to effectively utilize the optical output emitted from the LD 1 onto the disk surface 8, the L
The beam 9 of D1 is used by narrowing down the θ vertical direction of the shaping prism 10, but due to the structure of the shaping prism 10, it must be installed so that the θ vertical direction becomes the vertical direction.

[0005]

However, as shown in FIG. 3, in the conventional semiconductor device, since the long side direction of the fin 6 and the θ vertical direction are the same direction, the θ vertical direction is not vertical in the pickup portion. If the main body of the laser device is attached in such a direction, the long side direction of the fin 3 becomes the thickness direction 12 of the optical pickup portion, which causes a problem that the shape of the optical pickup portion becomes thick. Originally, the thickness direction 12 (vertical direction) of the optical pickup section is perpendicular to the disk surface 8, so as the optical pickup section becomes thicker, the overall system size also becomes larger. There is a problem in that the increased weight of the device itself reduces the processing speed of information.

The object of the present invention is to solve the above-mentioned problems of the prior art by changing the direction of the fins.

[0007]

[Means for Solving the Problems] The present invention is characterized in that the chip bonding surface of the semiconductor laser is set perpendicular to the short side direction of the rectangular fin.

[0008]

[Operation] When the semiconductor laser device of the present invention is attached to an optical pickup section, the short side direction of the rectangular fin becomes the longitudinal direction of the optical pickup section.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention. The difference in configuration from the conventional semiconductor laser device shown in FIG. 3 is that in this embodiment, the chip bonding surface of the semiconductor laser chip 6 is perpendicular to the short side direction of the rectangular fin 3. . Other points are the same as the conventional structure.

FIG. 2 shows an optical system of an optical pickup section using the above semiconductor laser device. In FIG. 1, the short side direction of the fin 3 and the bonding surface of the semiconductor laser chip 6 are set perpendicularly, that is, the short side direction of the fin 3 and the θ vertical direction are designed to be in the same direction. When the semiconductor laser device shown in FIG. 2 is used in an optical pickup section, the result will be as shown in FIG. That is, since it is necessary to arrange the semiconductor laser device so that the spreading direction of the light beam 9 is in the vertical direction 12 of the optical pickup portion, as shown in FIG.
When the semiconductor laser device of this embodiment is used, the short side direction of the fin 3 is arranged in the longitudinal direction 12. As is clear from FIG. 2, a space margin 13 occurs in the vertical direction 12 of the optical system in the optical pickup portion. Therefore, due to this margin 13, the dimension in the vertical direction 12 can be designed to be small. In an actual system, the dimension in the vertical direction 12 can be designed to be about 5 to 10 mm smaller. Fin 3 corresponding to the lateral direction of the optical pickup part (direction perpendicular to the page)
Since the long side direction of the fin is parallel to the disk surface 8, the length of the fin in the long side direction does not matter.

[0011]

Effects of the Invention By using the semiconductor laser device of the present invention in an optical pickup portion of an optical disk device or the like, the vertical dimension of the optical pickup portion can be designed to be small. Therefore, there is an advantage that the entire system, such as an optical disk device, in which the semiconductor laser device of the present invention is used can be made lighter and thinner.

[Brief explanation of drawings]

FIG. 1 shows a front view and a side view of an embodiment of the present invention.

FIG. 2 shows the structure of an optical pickup portion of an optical disc device using the above embodiment.

FIG. 3 shows a front view and a side view of a conventional semiconductor laser device.

FIG. 4 shows the structure of an optical pickup section using a conventional semiconductor laser device.

[Explanation of symbols]

1-Semiconductor laser 2-High frequency module 3-Fin 4- Shield case 6-Laser chip

Claims (1)

[Claims] 1. A semiconductor laser device that integrates a semiconductor laser, a high-frequency module containing a circuit for forming a high-frequency current to be superimposed on the semiconductor laser drive current in a shield case, and a rectangular fin for attaching to the main body of the laser device. A semiconductor laser device according to claim 1, wherein a chip bonding surface of the semiconductor laser is set perpendicular to a short side direction of the rectangular fin.