JPH0582832A - Photo interrupter - Google Patents

Abstract

PURPOSE:To enable the replacement and the mounting of an optical element and to reduce the size of an optical element by using a ferromagnetic material for a part of the optical element and a magnet for the case, at least a portion thereof holding the optical element, in fabrication. CONSTITUTION:A ferromagnetic plate 8 is stuck on the whole surface of an optical element 1a, and a case 2a is fabricated using a magnet. Thus, by using a magnet to secure the optical element and the case, a space to which adhesive is to be applied becomes unnecessary, only a little space being required for optical axis adjustment. A nickel plate, for example, is preferable for a material of the ferromagnetic plate 8. Thus, fixing an optical element and the case 2a by use of magnetic force provides a smaller photo interrupter such that the replacement and mounting of an optical element is easy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo interrupter in which a light emitting element body and a light receiving element body are integrally incorporated in one case and which detects an object by the amount of light transmitted or reflected.

[0002]

2. Description of the Related Art Usually, a method of fixing a photo interrupter has a structure in which an optical element body is resin-sealed to a main body portion (case) by an adhesive or thermocompression bonding.

FIG. 3 is a sectional view of a transmission type photo interrupter showing a conventional example. Conventionally, in this type of photo interrupter, as shown in FIG. 3, for example, an optical element body 1 in which optical elements are resin-sealed faces each other to form a case 2.
And was fixed by adhesion with the resin body 5. A lens 3 is attached to the optical element body 1 to effectively project and collect light, and a lead wire 4 projects from the case 1 as an input / output lead.

[0004]

The above-described conventional method of fixing the optical element body in the photo interrupter has a drawback that the space for applying the adhesive is required in the case and the main body cannot be made small and thin. . Further, in the case of an adhesive, there is a drawback that it takes time to apply the adhesive and to cure the resin. Further, with fixing using an adhesive or thermocompression bonding, once fixed, the optical axis deviation of the optical element cannot be corrected, resulting in a defective product. Moreover, even if the product becomes defective, it is difficult to replace it with a good optical element body.

An object of the present invention is to provide a photointerrupter which can easily fix and replace the optical element body and can be further miniaturized in order to solve such a problem.

[0006]

In the photo interrupter of the present invention, an optical element is made of a ferromagnetic material, and a main body (case) into which the optical element can be inserted is made of a magnet. There is.

[0007]

The present invention will be described below with reference to the drawings.

FIG. 1A is a sectional view showing an embodiment of the photo interrupter of the present invention, and FIG. 1B is a sectional view of an optical element body of the photo interrupter of FIG. 1A. In this photo interrupter, as shown in FIG. 1, the ferromagnetic plate 8 is attached to one surface of the optical element body 1a, and the case 2a is made of a magnet.

By fixing the portions to be fixed to each other with a magnet in this way, there is no need for a space for the adhesive to enter, and a small space for adjusting the optical axis is sufficient.
It is desirable to use, for example, a nickel plate as the ferromagnetic plate.

FIG. 2 is a sectional view showing an optical element body in another embodiment of the photo interrupter of the present invention. The optical element body of this photo interrupter is obtained by covering the resin body 6 in which metal powder is mixed, which is manufactured by mixing the conventional resin body 7 with the ferromagnetic metal powder and the resin. In this way, if the resin outer shell having magnetism is formed by sealing the optical element with resin,
The same effect as that of the above-described embodiment can be obtained.

In this embodiment, the transmissive photo interrupter has been described, but a reflective photo interrupter is also applicable. Further, it is obvious that only the fixing portion may be made of a magnet instead of manufacturing the entire case by a magnet.

[0012]

As described above, according to the present invention, by fixing the optical element body and the main body portion (case) by magnetic force, it is possible to replace and install the optical element body easily and to provide a more compact photo interrupter. It has the effect of being obtained.

[Brief description of drawings]

FIG. 1A is a sectional view of a photo interrupter showing an embodiment of the present invention, and FIG. 1B is a sectional view of an optical element body of the photo interrupter of FIG. 1A.

FIG. 2 is a cross-sectional view of an optical element body in another embodiment of the photo interrupter of the present invention.

FIG. 3 is a cross-sectional view of a photo interrupter showing a conventional example.

[Explanation of symbols]

 1,1a Optical element body 2,2a Case 3 Lens 4 Lead wire 5,7 Resin body 6 Metal powder mixed resin body 8 Ferromagnetic plate

Claims (3)

[Claims] 1. In a photo interrupter in which a light emitting element body and a light receiving element body are incorporated in one case, a part of the optical element body is made of a ferromagnetic material, and at least the optical element body of the case is fixed. A photo interrupter in which the part is made of a magnet. 2. The photo interrupter according to claim 1, wherein the ferromagnetic material has a plate shape. 3. A photo interrupter, wherein the magnetic material is a powder of a ferromagnetic material mixed in a resin body.