JP2800171B2 - Photo-interrupter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo interrupter, and more particularly, to a structure of a light path reflector.

[0002]

2. Description of the Related Art The conversion of light into electricity or the conversion of electricity into light is collectively referred to as photoelectric conversion. A photoelectric conversion element having a light-emitting portion and a light-receiving portion which are electrically insulated and coupled by light is referred to as a photoelectric conversion device. It is called a coupling element, and the optical coupling element is roughly classified into a photocoupler, a photointerrupter, and a photosensor. In any element, a combination of an infrared light emitting diode as a light emitting portion and a silicon phototransistor as a light receiving portion is common.
As shown in FIG. 3, the photo-interrupter, which is an optical coupling element, has a light-emitting portion 13 and a light-receiving portion 14 opposed to each other in a pair of protrusions provided at a predetermined interval on an upper end of a housing 15. It is arranged so that it can detect what is located between the projections through the transmission holes 16 formed on the opposing surfaces of the projections, and controls the rotation speed of the motor, the card reader and the FA. It is used for the intended equipment. In the conventional photointerrupter, since the light emitting unit 13 and the light receiving unit 14 face each other, a method of mounting discrete components, which are the light emitting element 13 and the light receiving element 14, on the printed wiring board 17 is generally adopted. Have been. In order to mass-produce these components at a low cost, mount the chip components into a printed circuit board and perform reflow soldering.
A method using MT (surface mounting technology) is excellent. However, in the method using SMT, the chip parts as the light emitting element and the light receiving element are mounted at the positions facing the same direction on the printed circuit board. In this structure, the light receiving section directly receives the light from the light emitting section. There is a problem that they cannot do this.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a light emitting element and a light receiving element mounted in a position facing the same direction on a printed circuit board in a system using SMT. In this state, a photointerrupter having a structure equivalent to that of a light emitting unit and a light receiving unit facing each other is provided.

[0004]

According to the present invention, in order to solve the above-mentioned problems, a pair of protruding portions are provided at an upper end portion facing each other at a required interval, and an inclined surface is provided on one side surface of the protruding portions. A housing made of an infrared-transmissive resin provided symmetrically, a projection corresponding to the projection on both sides of the upper end, a printed circuit board for SMT disposed in the housing, and an inclined surface of the housing. A light-emitting element and a light-receiving element respectively attached to the convex portion of the printed board so as to face each other,
The present invention provides a photointerrupter comprising a reflector attached to an inclined surface of the housing.

[0005]

With the above construction, in the photointerrupter according to the present invention, the light emitted from the light emitting element is reflected by the reflector attached to one of the inclined surfaces, and the reflected light is reflected on one of the protrusions of the housing. Through the wall of the housing, pass through the outside of the housing, pass through the wall of the other protrusion of the housing again, and are reflected by the reflector attached to the other inclined surface. The reflected light is received by the light receiving element. Therefore, even if the light emitting element and the light receiving element are mounted on the printed circuit board at positions facing in the same direction, light from the light emitting element can be received by the light receiving element.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of one embodiment of a photointerrupter according to the present invention, and FIG. 2 is a sectional view of a main portion of one embodiment of a photointerrupter according to the present invention.
2A is a plan sectional view of a main part, and FIG. 2B is a side sectional view of a main part. In the figure, reference numeral 1 denotes a housing made of an infrared transmitting resin, which is provided with a pair of opposing projections 2 and 3 at the upper end, and symmetrically provided with inclined surfaces 4 and 5 on one side of the projections. Is provided with a mounting portion 6 having a mounting hole,
Reference numeral 7 denotes a printed circuit board for SMT disposed in the housing 1. A projection 8 is provided at an upper end corresponding to the protrusions 2 and 3, and a lead 9 is connected to a lower end. Further, a light emitting element 10 and a light receiving element 11, which are chip components, are mounted on the convex portions 8 provided on the printed circuit board 7 so as to face the inclined surfaces 4, 5 of the housing 1, respectively. A reflecting plate 12 that reflects light is attached to the inclined surfaces 4 and 5 of the housing 1. Regarding the light path, first, the light emitted from the light emitting element 11 is reflected by the inclined surface 4, and the reflected light passes through the wall surface of the projection 2 of the housing 1, passes through the outside of the housing 1, and returns to the housing 1.
The light transmitted through the wall surface of the projection 3 is reflected by the inclined surface 5, and the light reflected by the inclined surface 5 is received by the light receiving element 11. If the reflection plate 12 is attached to the inclined surfaces 4 and 5 of the housing 1 from the outside, the inside of the housing can be made a simple structure, so that the housing can be formed without using a split mold. You can do it. Further, in the above-mentioned housing made of the infrared-transmissive resin, by using the member made of the infrared-transmissive resin only for a portion that becomes a light path, the cost of the members used can be reduced.

[0007]

As described above, in the photointerrupter according to the present invention, the light emitted from the light emitting element is reflected by the reflector attached to one of the inclined surfaces, and the reflected light is reflected on one side of the housing. Through the wall of the projection,
The light passes through the outside of the housing, passes through the wall surface of the other protrusion of the housing again, and is reflected by the reflector attached to the other inclined surface. The reflected light is received by the light receiving element. Even if the elements are mounted in the same direction on the printed circuit board, the light from the light emitting element can be received by the light receiving element.
It can be produced at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of the structure of a photointerrupter according to the present invention.

FIG. 2 is a cross-sectional view of a main part of one embodiment of the structure of the photointerrupter according to the present invention.

FIG. 3 is a sectional view of a main part of an example of the structure of a conventional photointerrupter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Projection part 3 Projection part 4 Inclined surface 5 Inclined surface 6 Mounting part 7 Printed circuit board 8 Convex part 9 Lead 10 Light emitting element 11 Light receiving element 12 Reflector

Claims (3)

(57) [Claims] 1. A housing made of an infrared-transmissive resin having a pair of projections facing each other at a predetermined interval at an upper end thereof, and having an inclined surface symmetrically provided on one side surface of the projections. Protrusions corresponding to the protruding portions are provided on both sides of the portion, and the SMT printed circuit board disposed in the housing and a light emitting device mounted on the protruded portion of the printed circuit board so as to face the inclined surface of the housing. An element and a light receiving element,
A photointerrupter, comprising: a reflector attached to an inclined surface of the housing. 2. The photo-interrupter according to claim 1, wherein said reflection plate is attached to an outside of an inclined surface of said housing. 3. The photo-interrupter according to claim 1, wherein an infrared transmitting resin is used only in a portion of the housing that becomes a light path.