JPH11154343A - Case of laser source and light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable positioning highly accurately and installing a toric lens near a light emitting point of a laser source by providing a groove for placing a toric lens making it slidable along the direction of an optical axis of a laser beam. SOLUTION: A groove 1a of a V type for placing a toric lens 3 making it slidable along the direction of an optical axis of a laser beam emitted from a laser diode 2 is formed in a plastic package 1. A divergence angle of a laser beam L' passed through sliding the toric lens 3 on the groove 1a is observed in a state in which a laser beam L is emitted from the laser diode 2, and the toric lens is positioned at a position at which a convergence angle of a vertical direction coincides with a convergence angle of a horizontal direction. After positioning, the toric lens 2 is fixed on the groove 1a using, for example, resin adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a housing for accommodating a laser light source and a light emitting device for accommodating the laser light source in the housing, and more particularly, to a method for easily shaping a laser beam using small optical components. About what you did.

[0002]

2. Description of the Related Art A laser diode is used as a laser light source in an optical pickup for reproducing an optical disk or recording / reproducing a magneto-optical disk. As is well known, a laser beam emitted from a laser diode is vertically and horizontally. The divergence angles are different.

Therefore, in an optical pickup, a perfect circular laser beam is irradiated onto the recording surface of a disk by shaping the laser beam with a beam expander (enlarging the beam diameter in the direction of a small divergence angle). I have.

In a conventional optical pickup, an anamorphic system or a cylindrical lens is used as such a beam expander.

FIG. 3 shows an example in which a prism as an anamorphic system is used. An elliptical laser beam L emitted from a laser diode (not shown) and made parallel by a collimator lens 11 is used by two prisms 12. ,
The laser beam 13 is shaped into a perfect circular laser beam L ′ by 13.

FIG. 4 shows an example in which a cylindrical lens is used. An elliptical laser beam L made parallel by a collimator lens 11 is converted into a perfect circular laser beam L by two cylindrical lenses 14 and 15. '.

[0007]

However, the beam expander using the anamorphic system or the cylindrical lens has a disadvantage that it is relatively large and expensive.

On the other hand, it has been proposed to use a toric lens (a lens having at least one toric surface), which is a relatively small and inexpensive optical component, as a beam expander.

However, when a toric lens is used, it is necessary to install the toric lens near the light emitting point of the laser diode and to position the toric lens with respect to this light emitting point with high accuracy. Conventionally, it has been extremely difficult to position and install the toric lens with high precision near the light emitting point of the laser diode.

The present invention has been made in view of the above points, and is a housing of a laser light source, in which a toric lens can be positioned and installed with high accuracy near a light emitting point of the laser light source, An object of the present invention is to provide a light emitting device in which a laser light source is housed in such a housing.

[0011]

SUMMARY OF THE INVENTION A housing of a laser light source according to the present invention is provided for slidably mounting a lens having a toric surface along the optical axis of a laser beam emitted from the laser light source. It is characterized by having a groove.

According to this housing, the groove for slidably mounting the toric lens is provided along the optical axis direction of the laser beam. Therefore, by placing the toric lens in this groove, the toric lens can be placed near the light emitting point of the laser light source. Also,
By sliding the toric lens on this groove,
High-precision positioning of the toric lens with respect to the laser light source can be easily performed. Further, since the toric lens is slid in the optical axis direction, it is easy to obtain the optical characteristics of the toric lens.

Next, the light emitting device according to the present invention is characterized in that the housing accommodating the laser light source has such a groove, and the lens having the toric surface is fixedly installed on the groove. And

According to this light emitting device, the toric lens is fixed near the groove so as to be installed near the light emitting point of the laser light source. Further, as a step before fixing the toric lens in this manner, highly accurate positioning of the toric lens on the groove can be easily performed as described above, and the optical characteristics thereof can be sufficiently obtained.

In addition, since the light emitting device itself is provided with a toric lens as a beam expander (ie, the laser light source and the beam expander are provided in the same unit), an optical pickup or the like provided with the light emitting device is used. Further reduction in the number of parts and size reduction can be realized.

[0016]

FIG. 1 shows an example of the configuration of a plastic package as a housing of a laser light source according to the present invention. The plastic package 1 includes a laser diode 2 for an optical disk (for example, a wavelength of about 780 n for reproducing a compact disk or recording and reproducing a magneto-optical disk)
m or a laser diode that emits a laser having a wavelength of about 650 nm for reproducing digital video discs.

The plastic package 1 has a laser diode 2 housed in the plastic package 1.
A V-shaped groove 1a for slidably mounting the toric lens 3 is formed along the optical axis direction of the laser beam emitted from the laser beam.

As the toric lens 3, a lens having one surface as a toric surface and another surface as a cylindrical surface may be used, or a lens having two surfaces as both toric surfaces may be used. You may. Further, in the figure, the toric lens 3 has a cylindrical shape, but may have another shape.

The plastic package 1 is formed integrally with the lead frame 4. The lateral portion of the outer peripheral surface of the plastic package 1 has cylindrical surfaces 1b and 1c which form a part of a cylinder having a constant radius.

FIG. 2 shows an example of an operation for installing a toric lens using this plastic package. First, as shown in FIG. 2A, the toric lens 3 is placed at an appropriate position in the groove 1a of the plastic package 1 in which the laser diode 2 is housed.

Next, with the laser beam L emitted from the laser diode 2, the divergence of the laser beam L 'transmitted through the toric lens 3 while sliding the toric lens 3 on the groove 1a as shown in FIG. 2B. Observe the corner. Then, the toric lens 3 is positioned at a position where the divergence angles in the vertical direction and the horizontal direction match.

As described above, the toric lens 3 is connected to the groove 1a.
And slide the laser diode 2
The toric lens 3 can be easily positioned and installed in the vicinity of the light emitting point. Further, since the toric lens 3 is slid in the optical axis direction, the optical characteristics of the toric lens 3 can be easily obtained.

When the positioning of the toric lens 3 is completed, the toric lens 3 is fixed on the groove 1a using, for example, a resin adhesive. Then, for example, the opening (the portion where the laser diode 2 and the groove 1a are exposed) of the plastic package 1 is covered with a lid made of plastic or glass, so that the light emitting unit is a unit in which the laser diode 2 is housed in the plastic package 1. Complete the device.

According to this light emitting device, the toric lens 3 is set near the light emitting point of the laser diode 2 by being fixed on the groove 1a. As described above, as a step before fixing the toric lens 3, the toric lens 3 is easily positioned with high precision as described above, and its optical characteristics are sufficiently exhibited.

Moreover, since the light emitting device itself is provided with the toric lens 3 as a beam expander (ie, the laser diode 2 and the beam expander are provided in the same unit), the optical pickup provided with the light emitting device The number of parts and the size can be further reduced.

When the light-emitting device is provided in the optical pickup, a light-emitting device sliding drive mechanism provided in the same optical pickup (for adjusting the focus error signal, the light-emitting device is moved in the emission direction of the laser beam L). ) Are directly received by the cylindrical surfaces 1b and 1c of the plastic package 1.

As described above, since the plastic package 1 has the cylindrical surfaces 1b and 1c, the plastic package can be easily received by the driving mechanism as in the case where the outer peripheral surfaces of the plastic package are all flat. Since it is not necessary to attach the optical pickup to another component, the number of components of the optical pickup can be reduced and the size of the optical pickup can be reduced.

In the above example, the V-shaped groove is formed in the plastic package. However, a groove having an appropriate shape in which the toric lens can be slidably mounted may be formed in the plastic package.

In the above example, such a groove is formed in the plastic package. However, such a groove may be formed in a housing (for example, a can package) for storing a laser diode other than the plastic package.

Further, in the above example, the present invention is applied to a housing for accommodating a laser diode for an optical disk and a light emitting device having such a laser diode accommodated in the housing, but other appropriate laser diodes are accommodated. The present invention may be applied to a light emitting device in which a housing or a laser diode thereof is housed.

In the above example, the portion on the lateral side of the outer peripheral surface of the plastic package is a cylindrical surface. However, an appropriate portion of the outer peripheral surface or the entire outer peripheral surface may be a cylindrical surface. Or, conversely, the entire outer peripheral surface may be flat.

The present invention is not limited to the above embodiment,
It goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0033]

As described above, according to the housing of the laser light source according to the present invention, the groove for slidably mounting the toric lens is provided along the optical axis direction of the laser beam. . Therefore, by placing the toric lens in this groove, the toric lens can be placed near the light emitting point of the laser light source. In addition, by sliding the toric lens on the groove, highly accurate positioning of the toric lens with respect to the laser light source can be easily performed. Further, since the toric lens is slid in the optical axis direction, it is easy to obtain the optical characteristics of the toric lens.

Next, according to the light emitting device of the present invention, the toric lens is set near such a groove, thereby being set near the light emitting point of the laser light source.
Further, as a step before fixing the toric lens in this manner, highly accurate positioning of the toric lens on the groove can be easily performed as described above, and the optical characteristics thereof can be sufficiently obtained.

Moreover, since the light emitting device itself is provided with a toric lens as a beam expander,
Further reduction in the number of components such as an optical pickup provided with the light emitting device and downsizing can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a configuration of a housing of a laser light source according to the present invention.

FIG. 2 is a perspective view showing an example of an operation of installing a toric lens using the housing of FIG. 1;

FIG. 3 is a diagram illustrating an example of a configuration of a conventional beam expander.

FIG. 4 is a diagram illustrating an example of a configuration of a conventional beam expander.

[Explanation of symbols]

1 plastic package, 1a groove, 1b, 1
c cylindrical surface, 2 laser diode, 3 toric lens, 4 lead frame, 11 collimator lens, 12, 13 prism, 14, 15 cylindrical lens

Claims (2)

[Claims] 1. A housing for housing a laser light source, comprising: a groove for slidably mounting a lens having a toric surface along an optical axis direction of a laser beam emitted from the laser light source. Characteristic laser light source housing. 2. A light emitting device in which a laser light source is housed in a housing, wherein the housing slidably mounts a lens having a toric surface along an optical axis direction of a laser beam emitted from the laser light source. A light-emitting device, comprising: a groove having a toric surface fixedly disposed on the groove.