JPS6218059Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a photoelectronic device that receives and detects the projected light from a light emitting element with a light receiving element, amplifies the received light output of this light receiving element, and operates a switching circuit. This invention relates to a switch, and in particular to an improvement in a case that houses a light receiving element.

[Prior art and its problems]

This type of photoelectric switch generally guides the projected light to the light-receiving element through the light-receiving lens, but when the light-receiving element is housed in the case, it goes without saying that the lens must be attached to the light-receiving surface of the case. There must be. In order to attach a lens to a case in this way, reliable adhesion is required, so consideration must be given to the mounting structure between the case and lens, and attention must also be paid to the sealing of the lens mounting surface. However, the mounting structure becomes complicated.

Additionally, ambient light may enter the light receiving element, causing it to malfunction.

[Purpose of invention]

The present invention was made in view of the above points,
The purpose is to simplify the mounting structure between the case and the lens, and to prevent the light receiving element from malfunctioning due to the incidence of disturbance light.

[Structure and effect of the idea]

In order to achieve the above object, the present invention includes a light receiving element that receives and detects projected light, an amplifier circuit that amplifies the output of this light receiving element, and a switching circuit that performs a switching operation based on the output of this amplifier circuit.
In the photoelectric switch, the photoelectric switch includes a case that houses the light-receiving element, an amplifier circuit, and a switching circuit, and a lens provided in front of the light-receiving element and attached to a part of the case, wherein the case and the lens are integrated. This photoelectric switch is characterized in that it is formed from a resin that transmits only infrared light and red visible light.

With the above configuration, in the present invention, the lens portion is integrally formed with the case at a predetermined location on the light-receiving surface of the case, so there is no need for a mounting member or the like for attaching the lens to the case. Therefore, the structure is simple,
Moreover, the seal between the lens and the case is also ensured.

Furthermore, since the case is molded from a resin that transmits only infrared light and red visible light, the interior of the case is hardly visible to the naked eye, which is desirable from an aesthetic point of view. In addition, since almost no disturbance light passes through, the light receiving element will not malfunction due to disturbance light, and an extremely safe photoelectric switch can be provided when controlling other devices etc. using the light reception signal. Furthermore, even if an indicator light such as a red light emitting diode is provided inside the case to indicate the operation of the photoelectric switch, the lighting state of the indicator light can be confirmed from the outside.

〔Example〕

Examples of this invention will be described below.

In the drawing, reference numeral 11 denotes a photoelectric switch in which an emitter and a receiver are housed integrally in one case, and this photoelectric switch 11 is generally a light emitter that emits infrared light, such as an infrared light emitting diode. It is used as a so-called reflective photoelectric switch in which the light projected from the element is reflected by an object to be detected (not shown) and the reflected light is received and detected by the light receiving element 13. 14 is a case, the details of which will be described later. 15 is a printed circuit board, and this printed circuit board 15 includes a detection circuit for detecting the output of the light receiving element 13, an amplifier circuit for amplifying the output of this detection circuit, a switching circuit that performs switching operation based on the output of this amplifier circuit, etc. An electronic circuit 17 is wired therein, and an indicator light 18 such as a red light emitting diode for displaying the operating status of the switching circuit and a hood 16 are also provided. The indicator light 18 is fixed to the printed circuit board 15 by a fixture 19. The hood 16 is integrally formed with a part for guiding light from the light emitting element 12 to the outside and a part for guiding light from the outside to the light receiving element, and is fixed to the printed circuit board 15. A cable 20 is provided for supplying power to the electronic circuit 17 and transmitting the output of the electronic circuit 17 to the outside.

In addition, the opening on the back of the case 14 is equipped with a packing 22.
It is covered with a lid 21 on which is arranged. Mata lid 21
A packing 23 is inserted into the cable pull-out hole, and a packing 24 is fixed with a screw.

Lens portions 14a and 14b are provided at predetermined locations on the light emitting and receiving surface of the case 14, respectively.

The lens portions 14a, 14b are formed integrally with the case 14 when the case 14 is molded. In this way, since the lens portions 14a and 14b are formed integrally with the case during the molding process, there is no need for any attachment member between the lens and the case.

In particular, in a photoelectric switch with an integrated emitter and receiver as in this embodiment, normally at least two lenses must be attached to the case, but with this invention, the lenses are attached to the case. This is extremely meaningful as there is no need to attach it.

In addition, since the material of the case is made of resin that transmits only infrared light and red visible light, an infrared light emitting diode is used as the light projecting element 12, and an infrared light emitting diode is used as the indicator light 18.
A red light emitting diode is used as the light source.

For this reason, it is difficult to see the inside of the case 14,
The operating state of the indicator light 18 itself can be confirmed. Furthermore, since the entire case 14 is made of the above-mentioned material, the mounting location of the indicator light 18 is not limited, and there is also the effect that circuit mounting on the printed circuit board 15 is easy.

[Brief explanation of the drawing]

The drawing is a sectional view showing an embodiment of this invention. 11: Photoelectric switch, 12: Light projecting element, 13:
Light receiving element, 14: case, 14a, 14b: lens portion, 18: indicator light.

Claims (1)

[Claims for Utility Model Registration] A light receiving element that receives and detects projected light, an amplifier circuit that amplifies the output of the light receiving element, a switching circuit that performs a switching operation based on the output of the amplifier circuit, and the light receiving element and the amplifier circuit. A photoelectric switch including a case for housing a switching circuit, and a lens provided in front of the light receiving element and attached to a part of the case, wherein the case and the lens are integrally formed, and the infrared light A photoelectric switch characterized by being molded from resin that transmits only red visible light.