JPH10307045A - Transmission photosensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transmission photosensor which can be used easily and whose performance can be enhanced by a method wherein the bottom face of a groove part is formed to be an uneven shape with reference to the direction of an optical axis which connects a light-emitting element to a light-receiving element. SOLUTION: A light-emitting element 2 and a light-receiving element 3 are arranged so as to be faced inside a case 1, and a slit 4 and a slit 5 are formed at the case 1 in the front part of its light-emitting part 2a and in the front part of its light-receiving part 3a. The terminal 6 of the light-emitting element 2 and the terminal 7 of the light-receiving element 3 are installed at the outside of the case 1 through respective holes in a read lid 8. The shape of the groove-part bottom face part 1b of a case groove part 1a used to arrange a shielding member 9 in which an opening part is formed is formed to be fine uneven parts whose cross section is mountain-shaped in a direction perpendicular to an optical axis. The uneven parts prevent the reflection in the direction of the light-receiving element 3 of diffused light received by the groove-part bottom face part 1b from the light-emitting element 2. Thereby, a photosensor is electrified, the light of the light-emitting element 2 is cut off/opened with reference to the light-receiving element 3 by the shielding member 9, and an output having a level difference is fetched from the light-receiving element 3. In this case, the light is cut off surely by the shielding member 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission type photo sensor.

[0002]

2. Description of the Related Art A conventional example of a transmission type photosensor will be described with reference to FIGS.

[0003] A light emitting element 2 and a light receiving element 3 are arranged at opposing positions in a case 1, and the front of the light emitting section 2 a of the light emitting element 2 and the light receiving section 3 a of the light receiving element 3 are provided on the front of the case 1. Are provided with slits 4 and 5.

The terminals 6 and 7 of the elements 2 and 3 are connected to a back cover 8.
Are arranged outside the case 1 through the holes.

[0005]

Such a configuration is a conventional example of a general transmission type photosensor. However, as the size of the configuration is reduced, the distance from the center of the optical axis 10 between the elements 2 and 3 is increased. The distance between the case groove portion 1a and the groove bottom portion 1b is shortened, and the lens portions are abolished in order to reduce the size of the elements 2 and 3 as well.

Therefore, when the light to the light receiving element 3 is to be cut off by the shielding member 9 as much as possible, the light reflected on the groove bottom part 1b is easily sneak into the light receiving element 3 and the bottom part 1b In consideration of the fact that the reflectance is improved due to the adhesion of paper dust and dust to the surface, it is necessary to bring one of the elements 2 and 3 or the shielding member 9 as close as possible to the bottom surface 1b.

However, it is extremely difficult to secure the position required above for a miniaturized photosensor.

In order to obtain high responsiveness with an inexpensive small-sized phototransistor, it is necessary to minimize the sneak of light at the time of shading in order to secure a difference in output level between when light is transmitted and when light is blocked.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and aims to improve the usability of a small and inexpensive transmissive photosensor and to improve the functional quality / reliability such as the performance. And

[0010]

As a means for solving this problem, a transmission type photosensor according to the present invention emits light through a transmission part which can transmit light and a groove through which a blocking part which blocks light passes. In a transmissive photosensor in which an element and a light-receiving element are arranged to face each other and a change in light emitted from the light-emitting element when the transmissive portion and the blocking portion pass through, the bottom surface of the groove is formed by the light-emitting element and the light-receiving portion. It is characterized by being formed in an uneven shape with respect to the optical axis direction connecting the element.

The bottom of the groove is formed in a convex shape with the optical axis as a peak.

Further, the bottom surface of the groove is formed by a support member for supporting the transmission type photosensor.

According to the first aspect of the present invention, since the unevenness is formed in the direction of the optical axis connecting the light emitting element and the light receiving element, the diffused light emitted from the light emitting element is irregularly reflected at the bottom surface and the reflected light is reflected. Light does not reach the light receiving element side. Therefore,
The detection accuracy of ON / OFF of the photo sensor is improved.

According to the second aspect, the diffused light radiated to the bottom surface is divided into right and left with the peak as a boundary, so that the diffused light does not reach the light receiving element side, which is more effective.

According to the third aspect, since only the support member can be changed, there is versatility.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION In the following, claim 1 of the present invention,
2 The contents of the description are explained.

In FIGS. 1 and 2 which are the first embodiment of the present invention, a light emitting element 2 and a light receiving element 3 are arranged at opposing positions in a case 1 of a transmission type photo sensor. Slits 4 and 5 are provided in the case 1 on the front surfaces of the light emitting section 2a of the light emitting element 2 and the light receiving section 3a of the light receiving element 3 respectively.

The terminals 6 and 7 of the elements 2 and 3 are connected to a back cover 8.
Are arranged outside the case 1 through the holes.

The groove bottom surface 1b of the case groove 1a for disposing the shielding member 9 provided with the opening 9a has an optical axis 10
On the other hand, fine irregularities having a mountain-shaped cross section in the vertical direction are provided.

The uneven shape is designed so that the diffused light received by the bottom surface portion 1b from the light emitting element 2 is not reflected in the direction of the light receiving element 3, so that the photo sensor is energized to emit the light emitted from the light emitting element 2. When an output having a level difference is obtained from the light receiving element 3 by blocking / releasing the light receiving element 3 with the shielding member 9 rotating about the rotation axis 9b, the light is blocked by the shielding member 9. By doing so, the light receiving element 3 can reliably block light without being affected by the reflected light from the bottom surface portion 1b.

In FIGS. 3 and 4, which are a second embodiment of the present invention, a shielding member 9 having an opening 9a is disposed.
The shape of the bottom portion 1b is perpendicular to the vertical plane formed parallel to the direction of the optical axis 10 between the conventional two elements 2 and 3 and from the center of the optical axis 10 to the direction immediately below. It is formed from two planes with an angle from the plane.

The bottom portion 1b according to the shape of this embodiment is
In order to reflect the diffused light emitted from the light emitting element 2 in a direction other than the light receiving element 3, the photo sensor is energized, and the light emitted from the light emitting element 2 is transmitted to the shielding member 9 rotating about the rotation axis 9b. When an output having a level difference is obtained from the light receiving element 3 by blocking / releasing the light receiving element 3, the light is blocked by the shielding member 9 so that the light receiving element 3 is separated from the bottom surface 1 b. The light can be reliably blocked without being affected by the reflected light from the light source.

Further, according to the present embodiment, the bottom portion 1
b. Even if paper dust, dust, etc. adhere to the surface of 1c, the surface of the paper dust or the like becomes a slope having a peak 1c just below the optical axis, so that the diffused light is divided into right and left, so that it does not reach the light receiving element. The accuracy is improved as compared with the first embodiment.

In FIGS. 5 and 6, which are the third embodiment of the present invention, a shielding member 9 having an opening 9a is arranged.
The shape of the bottom portion 1b is such that the shape of the bottom portion 1b composed of the two planes of the second embodiment is parallel to the direction of the optical axis 10 between the two elements 2 and 3 and in the direction directly below the center of the optical axis 10. It is formed by a curved surface having a vertex at the position immediately below the vertical plane to be formed.

The bottom portion 1b according to the shape of the present embodiment is
In order to reflect the diffused light emitted from the light emitting element 2 in a direction other than the light receiving element 3, the photo sensor is energized, and the light emitted from the light emitting element 2 is transmitted to the shielding member 9 rotating about the rotation axis 9b. When an output having a level difference is obtained from the light receiving element 3 by blocking / releasing the light receiving element 3, the light is blocked by the shielding member 9 so that the light receiving element 3 is separated from the bottom surface 1 b. The light can be reliably blocked without being affected by the reflected light from the light source.

Further, according to this embodiment, the bottom portion 1b
Even if paper dust, dust, or the like adheres to the upper portion, the reflected light to the light receiving element 3 can be reduced more reliably than in the first embodiment.

Next, the contents of the third aspect of the present invention will be described.

In FIGS. 7 and 8, which are a fourth embodiment of the present invention, a light emitting element 2 and a light receiving element 3 are arranged at opposing positions in a case 1 of a transmission type photo sensor. Slits 4 and 5 are provided in the case 1 on the front surfaces of the light emitting section 2a of the light emitting element 2 and the light receiving section 3a of the light receiving element 3 respectively.

The terminals 6 and 7 of the elements 2 and 3 are connected to a back cover 8.
Are arranged outside the case 1 through the holes.

In order to mount and position the photosensor, the case 1 is held by the holder 11, and the case 1 is disposed on the groove bottom surface 1b of the case groove 1a for disposing the shielding member 9 having the opening 9a. In the shape of a certain holder bottom portion 11a, fine irregularities having a mountain-shaped cross section in a direction perpendicular to the optical axis 10 are provided.

The uneven shape is designed so that the diffused light received by the holder bottom surface 11a from the light emitting element 2 is not reflected in the direction of the light receiving element 3, and the photo sensor is energized and emitted from the light emitting element 2. When an output with a level difference is obtained from the light receiving element 3 by blocking / releasing the light to the light receiving element 3 by the shielding member 9 rotating about the rotation axis 9b, the light is applied to the light by the shielding member 9. , The light receiving element 3 can reliably block the light without being affected by the reflected light from the holder bottom surface 11a.

The shape of the holder bottom portion 11a of this embodiment is the same as that of the bottom portion 1b of the second and third embodiments.
It is needless to say that the same effect can be obtained by adopting the same surface shape as described above.

[0033]

According to the present invention, since the bottom surface of the groove is formed in an uneven shape with respect to the direction of the optical axis connecting the light emitting element and the light receiving element, the reflected light from the bottom surface of the groove when the photo sensor is energized, Light does not enter the light receiving element, and the light shielding is reliably blocked by the shielding member, so that fine position adjustment and dimensional control are not required, and the output level difference due to release / blocking of light is easily ensured. Even if the distance from the center of the optical axis to the bottom of the groove is short, reflection at the bottom of the groove can be prevented, so that a more compact, inexpensive, high-performance, and easy-to-use transmissive photosensor can be provided.

According to the second aspect, the diffused light radiated to the bottom surface is divided into right and left portions with a peak as a boundary, so that the diffused light does not reach the light receiving element side, which is more effective.

Further, the same effect can be easily obtained by performing the same improvement as described above using another member such as a holder on the transmission type photosensor not implemented in the present invention.

[Brief description of the drawings]

FIG. 1 is a front cross-sectional view for illustrating a transmission type photosensor in detail according to a first embodiment of the present invention.

FIG. 2 is a front perspective view for illustrating a transmission type photosensor in detail according to the first embodiment of the present invention.

FIG. 3 is a side cross-sectional view for illustrating a transmission type photosensor in detail according to a second embodiment of the present invention.

FIG. 4 is a front perspective view of a transmission-type photosensor, showing a second embodiment of the present invention.

FIG. 5 is a side sectional view of a transmission type photosensor, showing a third embodiment of the present invention.

FIG. 6 is a front perspective view of a transmission type photosensor, showing a third embodiment of the present invention.

FIG. 7 is a front sectional view of a transmission type photosensor according to a fourth embodiment of the present invention.

FIG. 8 is a front perspective view of a transmission type photosensor, showing a fourth embodiment of the present invention.

FIG. 9 is a front cross-sectional view of a transmission type photosensor showing an example of the related art.

FIG. 10 is a front perspective view of a transmission type photo sensor, showing an example of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 1a Case groove 1b Groove bottom 2 Light emitting element 2a Light emitting 3 Light receiving element 3a Light receiving 4 Slit 5 Slit 6 Terminal 7 Terminal 8 Back cover 9 Shielding member 9a Opening 9b Rotation axis 10 Optical axis 11 Holder 11a Holder bottom

Claims (3)

[Claims] 1. A light-emitting element and a light-receiving element are arranged to face each other via a groove through which a light-transmitting transmitting part and a light-blocking part pass, and the light-transmitting part and the light-blocking part pass through. In the transmission type photosensor for detecting a change in light emitted from the light emitting element, a bottom surface of the groove is formed in a concave and convex shape with respect to an optical axis direction connecting the light emitting element and the light receiving element. A transmission type photosensor characterized by the above-mentioned. 2. The transmission type photo sensor according to claim 1, wherein a bottom surface of the groove is formed in a convex shape with the optical axis as a peak. 3. The transmission type photo sensor according to claim 1, wherein a bottom surface of the groove is formed by a support member for supporting the transmission type photo sensor.