JPS592545Y2 - Photo detection device - Google Patents

Description

[Detailed description of the invention] The invention consists of a light-emitting element such as a light-emitting diode and a light-receiving element such as a phototransistor, which are arranged opposite to each other with a detection object passing path in between, and a perforated plate or perforated tape is placed on this path. A photodetection element that detects the speed of passage through a body, and includes the light-emitting element, light-receiving element, amplifier (IC), and printed circuit board to which these elements are attached, all molded into a housing. This invention relates to a photo detection device.

The purpose of this invention is to integrally mold each of the above-mentioned elements into a housing, and to solve problems that occur after molding, such as misalignment of coaxiality between the light emitting element and the light receiving element (described later), and internal wiring. The aim is to eliminate problems such as wire breakage accidents.

The drawings will be explained below in comparison with a conventional device.

1A and 1B show an example of a device using this type of detection device, with A being a top view and B being a side view.

In the figure, 1 is the base, 2 is the motor attached to this base, and 3
is a rotating disk attached to the rotating shaft 2' of this motor, 4
is attached to the lower surface of this rotating disk coaxially with it,
Furthermore, the detection disk has a larger diameter than the rotary disk 3, and as shown in the figure, a plurality of perforations 4' are provided in a ring shape depending on the purpose.

Reference numeral 5 denotes a detection device, which has a recess 5' at approximately the center of its side surface, which serves as a path through which the detection object passes, and the detection plate 4 is placed in this recess.

On the other hand, a light-emitting element and a light-receiving element, which will be described later, are arranged in the upper and lower parts of the recess 5', facing each other so as to sandwich the detection plate 4, and the detection plate rotates as the motor 2 rotates. By passing the No. 4 perforation 4' between the above-mentioned elements, the rotational status of the motor 2, the status of the perforation 4', etc. are converted into electrical signals.

This type of device is applied to rotary encoders, pulse conversion sensors, tachometer sensors, etc.

Note that 6 is a lead wire for taking out the output of the detection device 5.

Conventionally, this detection device was usually molded so that a light emitting element and a light receiving element or two coils were placed facing each other and close to the detection plate. Alternatively, it is necessary to connect an oscillator, etc., and these were installed and wired separately from the detection device, but this would increase the number of work hours and was not a good idea. It was hoped that the two components would be housed together in one housing and molded.

However, this mold is not easy to make. For example, when molding with a normal mold, that is, a resin that has a high hardness after molding, when the resin deforms due to the influence of external temperature, humidity, etc. In particular, in cases such as the above case where an optical system is used as a detection element, there may be a coaxial error, that is, the adjustment is made so that the light emitted from the light emitting element just reaches the light receiving surface of the light receiving element. Moreover, since the number of internal wirings is increased compared to the conventional one, problems arise such as internal stress caused by deformation of the resin causing breakage in any of the wirings.

In view of this point, the present invention has made the above-mentioned mold possible while solving the above-mentioned problems.

What is shown in FIGS. 2A and 2B is a side view showing the detection element and the entire device (partially in section) of the photodetection device of the present invention, and the detection device 5 shown in FIG. As such, the shape and size are such that it can be applied as is.

In the figure, 7 is a light emitting element such as a light emitting diode, and 8 is a light emitting element)
A light-receiving element such as a transistor, 9 is inserted into a recess 9'.
It is a pre-molded body that is molded with coaxiality maintained between the parts, and is molded with a relatively hard resin, but the above-mentioned problem of deformation can be ignored for a product of this size (about the size of a caramel).

10 and 11 are lead wires for each element (two wires each).

A housing 12 is made of iron and has a size to accommodate the pre-molded body 9, an IC amplifier (not shown), a printed circuit board (not shown), and the like.

13 is a node wire, and 14 is a molding material.

In the present invention, the material of the molding material 14 is an extremely important element, and as a result of various experiments, silicone rubber, specifically two-component KE-1204L manufactured by Shin-Etsu Chemical Co., Ltd.
Good results were obtained with TV (A, B).

This resin has high insulation properties and maintains moderate elasticity even after curing.
It was confirmed that the internal stress due to aging is absorbed by its elasticity, and there is no adverse effect on the coaxiality of the detection element, and there is no possibility of internal wiring breaking, so there is no problem at all in practice. .

Since the present invention has the above-described configuration, it is possible to integrate the detection element of the optical system and the IC (amplifier), etc., which was previously difficult to implement due to the material of the molded resin, reducing assembly man-hours. It has excellent effects such as miniaturization of the device, elimination of the influence of external factors due to the mold, and no influence of aging due to the mold.

[Brief explanation of the drawing]

Figures 1A and B are top and side views showing the main parts of a device to which the device of the present invention can be applied, and Figures 2A and B are a portion of the detection element used in the device of the present invention and a portion of the entire device. FIG. 3 is a cross-sectional side view. 2...Motor, 4...Detection plate, 5...
...Detection device, 7...Light emitting element, 8...
. . . Light receiving element, 14 . . . Mold material.

Claims (1)

[Scope of utility model registration request] A photo sensor in which a light-emitting element and a light-receiving element, which are placed facing each other across the detection object passage path, and attached devices such as an amplification element and a board connected to these elements are housed in the same housing and integrally molded with silicone rubber. Detection device.