JPH02161782A - Photosensor - Google Patents

Abstract

PURPOSE:To make the outer shape to be compact by connecting a light-emitting element to a light-receiving element at a connecting part. CONSTITUTION:A light-emitting element 1 and a light-receiving element 2 are connected in one piece by a connecting part 3 consisting of a wedge part and a protrusion which is engaged to the wedge part so that a light-emitting surface 4 and a light-receiving surface 5 face each other. A protrusion nib for fixing 6 is provided on the side surface of the connecting part 3 and both are fixed firmly after connection. A light-emitting pallet 1a and a light-receiving pallet 2a are fixed on a lead frame 7 within the elements 1 and 2, are formed by a light-transmission resin 8, and are covered with a light-screening resin 9. A lens 10 consisting of the resin 8 is provided at the front surface of the elements 1 and 2 and is exposed to the outside world through a window pro vided at the resin 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an optical sensor in which a light emitting element and a light receiving element are combined and integrated.

[Conventional technology]

As shown in the exploded perspective view of FIG. 8, a conventional optical sensor includes a resin-molded light emitting element, such as an infrared light emitting diode 21, and a resin-molded light receiving element, such as a phototransistor, in a resin case 23 called a housing case. 22 was incorporated and fixed with adhesive.

Further, as shown in the perspective view of FIG. 9, which is seen through the sealing resin (--dotted chain line), the light emitting section 31 and the light receiving section 32 were integrally molded in a resin-sealed package 33.

[Problem to be solved by the invention]

As mentioned above, conventional optical sensors have a structure that incorporates a resin-molded light emitting element and light receiving element into a housing case, so they are naturally larger than the internal elements (light emitting element, light receiving element) alone, and are difficult to use. The housing case incorporates the internal elements and needs to be strong enough to support them, so the material that makes up the housing case needs to be sufficiently thick. For example, - polyethylene terephthalate used in the membrane requires a thickness of 0.5 mm or more. From the above points, there is a limit to the miniaturization of optical sensors with conventional structures. In addition, due to the structure described above,
Misalignment of internal elements due to variations in assembly work may cause optical axis misalignment between light emitting and light receiving, and low current conversion efficiency due to this optical axis misalignment.

Furthermore, in the case of an integrated molded structure that can be easily miniaturized, the light emitting side and the light receiving side are not completely optically independent, so light is reflected inside the resin, causing leakage on the light receiving side when the light emitting and receiving sides are far away. The current was relatively large. In addition, there was a drawback that there was no flexibility in the external shape, and in particular, when an unusual interval between light emission and light reception was required, a mold and lead frame that matched the requirement had to be prepared.

[Means to solve the problem]

The optical sensor according to the present invention includes a light emitting element having a light shielding structure,
By directly coupling the light-receiving elements, the conventional housing case is eliminated, resulting in a smaller external size.

〔Inferior Moon〕

Next, the present invention will be explained by examples.

Fig. 1 is a perspective view of the first embodiment of the present invention, Fig. 2(a)
1 is a side view of the embodiment shown in FIG. 1, FIG. 3B is a top view, and FIG.
The figure is a sectional view taken along the line AA in FIG. 2(b).

In these figures, the light-emitting element 1 and the light-receiving element 2 are integrally connected by a coupling part 3 formed by a wedge groove and a protrusion that fits into the wedge groove, with the light-emitting surface 4 and the light-receiving surface 5 facing each other. . Further, the side surface of the protrusion of the connecting part 3 has a fixing claw 6 as shown in the partial cross-sectional view of FIG. 4, so that the two are securely fixed after being combined. The internal structures of the light emitting element 1 and the light receiving element 2 are as shown in the cross-sectional view of FIG. , and is further covered with a light-shielding resin 9. Note that the light emitting element 1 and the light receiving element 2
A lens portion IO is provided on the front surface of each lens portion, and the surface of this lens portion is exposed to the outside world through a window provided in the light-shielding resin 9.

FIG. 5(a) is a side view of the second embodiment of the present invention;
b) is a top view, and FIG. 6 is a sectional view taken along line AA in FIG. 5(b). In these figures, a light-emitting element 11 and a light-receiving element 12 forming a reflective optical sensor are connected at a joint 3 with the light-emitting surface 4 and the light-receiving surface 5 facing upward in the same manner. As shown in the cross-sectional view of FIG. 6, the internal structure of these pellets is that each pellet lla and 12a is mounted on the upper end of the lead terminal 13, and each pellet blocks visible light but blocks infrared light. It is molded with a transmissive resin 14 that transmits light, and then covered with a light-shielding resin 9 on the outside. This example has the advantage that it is not affected by visible light components and is resistant to disturbance light.

〔Effect of the invention〕

As explained above, according to the present invention, it is easy to miniaturize the optical sensor because of the structure in which independent light emitting elements and light receiving elements are directly coupled.

That is, it is possible to reduce the volume to only the light emitting element and the light receiving element without being restricted by the structure, plate thickness, etc. of the housing case. Furthermore, since the light emitting element and the light receiving element are connected without adhesive, there are advantages in that a housing case is not used, the number of parts is small, and the number of assembly steps is reduced. Furthermore, because of the direct coupling, there is little variation in work during assembly, which reduces the possibility of optical axis misalignment between light emitting and light receiving, and low current conversion efficiency due to optical axis misalignment. Also,
Since both the light-emitting element and the light-receiving element have a light-blocking structure except for the light-emitting window and the light-receiving window, the light-emitting side and the light-receiving side are optically independent, and there is no light leakage current due to reflection within the resin.

Furthermore, as shown in the side view of FIG. 7, if multiple sizes of connection spacers 15 are prepared in advance, one or more connection spacers can be used to connect the light emitting element l and the light receiving element. By combining elements 2, arbitrary light emission and
An optical sensor having a light reception interval can be obtained.

In addition, light emitting and
For applications where the light receiving interval is as long as 30 to 40 cm and it is difficult to use an optical sensor with an integrated light emitting part and light receiving part, the light emitting part and the light receiving part can be separated and used as a single light emitting element and a light receiving element, respectively. In particular, it can be used without providing a case to prevent disturbance light or a slit to improve resolution.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the first embodiment of the present invention, Fig. 2(a) is a side view of the embodiment of Fig. 1, Fig. 3(b) is a top view, and Fig. 3 is Fig. 2(b). 4 is a partial sectional view showing the fixing claw of the joint, FIG. 5(a) is a side view of the second embodiment of the present invention, and FIG. 5(b) is a top view. , FIG. 6 is a sectional view taken along the line A-A in FIG. 5(b), FIG. 7 is a side view showing coupling using a spacer, FIG. 8 is a perspective view of an example of a conventional optical sensor, and FIG. FIG. 2 is a perspective view showing another example of a conventional optical sensor. ■, 11... Light emitting element, 2, 12...
Light receiving element, la, lla... Light emitting element pellet, 2a, 12a... Light receiving element pellet, 3...
...Connection part, 4, 14... Light emitting surface, 5, 1
5... Light receiving surface, 6... Fixing claw, 7
...Lead frame, 8...Transparent tm
m, 9... Light shielding resin, 10... Lens, 13... Lead terminal, 14... Infrared light transmitting resin. Agent Patent Attorney Shingi Uchihara

Claims (1)

[Claims] An optical sensor comprising a combination of a light-emitting element and a light-receiving element, characterized in that the light-emitting element and the light-receiving element have a coupling part for coupling to each other, and are integrally coupled by the coupling part. .