JPH0133888B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a waterproof photoelectric switch, and more particularly to a waterproof photoelectric switch in which a photoelectric element and amplifying switching circuitry are molded into a body.

In general, photoelectric switches are often used in locations that require waterproofing, and for this reason, conventional methods have been to encapsulate only the photoelectric elements, such as light-emitting diodes and phototransistors, in a waterproof package and separate them from the amplifier switching circuit. Often adopted. However, with this method, malfunctions are likely to occur due to noise, there are limits to the length of the wiring, and there are restrictions in that shielded wires must be used. , a built-in amplifier type in which the width increasing switching circuit component 2 and the photoelectric element 1 are integrated is provided, but in this case, the filter glass 11 that seals the window 15 of the photoelectric element 1 is fixed to the case 16. In addition, there were problems in that it took time and effort to use bushings 17 to fix the lead wires 6 to the case 16, and to seal the joints between the upper and lower cases 16.

The present invention has been made in view of the above points, and its main objectives are not only to have excellent waterproof properties, but also to be strong against vibrations and shocks, and to be able to reduce the directivity angle. An object of the present invention is to provide a waterproof photoelectric switch.

The present invention will be described in detail below based on embodiments shown in the figures. In the waterproof photoelectric switch according to the present invention, a photoelectric switch body 5 is constructed of a substrate 3 on which a photoelectric element 1 and a widening switching circuit component 2 are mounted, and a transparent front frame 4 rising upward from the front end of the substrate 3.
The photoelectric element 1 is embedded in an opaque synthetic resin body 7 together with a portion of the lead wire 6 extending further, and the photoelectric element 1 is fitted into a recess 8 formed on the rear surface of the transparent front frame 4. A transparent front frame 4 is provided with a through hole 10 that reaches the surface of the transparent front frame 4 at a position corresponding to the recess 8 in the front part 9 of the body 7 covering the front surface of the transparent front frame 4. An example is shown in which the front surface of the element 1 is covered with an infrared filter 11.
The transparent front frame 4 is molded from transparent synthetic resin, and the front end of the printed circuit board 3 on which the photoelectric element 1 and the wide switching circuit component 2 are mounted fits into the fitting recess 12 at the lower end of the transparent front frame 4, making it transparent. The front frame 4 is integrally connected to the base plate 3. As the photoelectric element 1, a light emitting diode is used when the photoelectric switch is used as a light emitting side, and a phototransistor is used when the photoelectric switch is used as a light receiving side, and is electrically connected to the printed circuit board 3. The photoelectric element 1 is fitted into a recess 8 formed approximately at the center of the rear surface of the transparent front frame 4 and held in a predetermined position.An infrared filter 11 is housed in the bottom of the recess 8, and the photoelectric element 1 is Infrared filter 11 on the front of 1
It is designed to be covered with The photoelectric switch body 5 obtained by combining the substrate 3 and the transparent front frame 4 in this way is subjected to a performance test in this state, and then molded into an opaque synthetic resin that will become the body 7 to complete the final product. The front surface of the transparent front frame 4 is completely covered except for a portion corresponding to the bottom of the recess 8, and a transparent hole 10 serving as an optical window is formed in the portion corresponding to the recess 8. As shown in FIG. 3, this through hole 10 is set to be smaller than the diameter of the photoelectric element 1 and the recess 8, and when the photoelectric switch is set to the light emitting side, light is emitted only directly in front of the photoelectric element 1. When it is sent out and used as a light receiving side, the directivity angle of the photoelectric switch is made small so that only light from the front can be detected.

As described above, the present invention provides a photoelectric switch body consisting of a substrate on which a photoelectric element and a widening switching circuit component are mounted, and a transparent front frame rising upward from the front end of the substrate, and a part of the lead wire extending from the substrate. Since the transparent hole is embedded in an opaque synthetic resin body, the transparent hole is formed to reach the surface of the transparent front frame, so there is no gap between the rear surface of the transparent hole and the front surface of the transparent front frame. Therefore, opaque synthetic resin can be encapsulated all over the parts so as to cover each part, and the encapsulation of this opaque synthetic resin has the effect of making it waterproof. It is possible to completely confine the body within the body, and not only is it highly waterproof, but also has the effect of being resistant to vibrations and shocks because each part is held in a fixed position. Further, the photoelectric element is fitted into the recess formed on the rear surface of the transparent front frame, and reaches the surface of the transparent front frame at a position corresponding to the recess in the front part of the body that covers the front surface of the transparent front frame, and the photoelectric element and Because it has a through hole that is smaller than the diameter of the recess, the photoelectric element is located inside the through hole, which reduces the directivity angle of the photoelectric element and increases directivity. It is possible,
Moreover, in order to increase this directivity, for example, if the recess into which the photoelectric element is fitted is lengthened, the axial direction of the recess becomes longer and the shape becomes larger. However, in the present invention, the diameter of the through hole is The directivity can be improved by making the switch smaller than the diameter of the recess and the diameter of the recess, and therefore, it is possible to provide a compact waterproof photoelectric switch with high directivity without increasing the size. . Furthermore, the filter covering the front side of the optoelectronic element can be easily accommodated in the recess.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a conventional example, Fig. 2 is a sectional view showing an embodiment of the present invention, and Fig. 3 is a partially enlarged sectional view showing the same effect. Width switching circuit components, 3 is the board, 4 is the transparent front frame, 5 is the photoelectric switch body, 6 is the lead wire, 7
is a body, 8 is a recess, 9 is a front part, and 10 is a through hole.

Claims (1)

[Claims] 1. The photoelectric switch body consists of a board on which a photoelectric element and width-enhancing switching circuit components are mounted, and a transparent front frame rising upward from the front end of the board, and a body made of opaque synthetic resin together with a portion of the lead wire extending from the board. A photoelectric element is inserted into a recess formed on the rear surface of the transparent front frame, and reaches the surface of the transparent front frame at a position corresponding to the recess on the front part of the body that covers the front surface of the transparent front frame. A waterproof photoelectric switch characterized by having a through hole set smaller than the diameter of the photoelectric element and the recess.