JPH07225272A - Object existence detector - Google Patents

Abstract

PURPOSE:To provide an object existence detector in which an object to be detected is detected surely and with high reliability or in which a detection level is set easily. CONSTITUTION:In an object existence detector which is provided with a reflection type optical sensor 1, a reflecting body 5 by which the optical axis of the reflection type optical sensor is made nonvertical to the detection light irradiation face of an object 2 to be irradiated, which is faced with the reflection type optical sensor and which is provided with a reflecting face perpendicular to the optical axis of the reflection type optical sensor is installed. In a state that the object to be detected does not obstruct the optical axis of the reflection type optical sensor, detection light 4 which is reflected by the reflecting object enters the reflection type optical sensor, and the reflection type optical sensor judges that the object to be detected does not exist. When the object to be detected obstructs the optical axis of the reflection type optical sensor, reflected light does not enter the reflection type optical sensor, and the reflection type optical sensor detects the existence of the object to be detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object presence / absence detection device, and more particularly to a light reflection type object presence / absence detection device.

[0002]

2. Description of the Related Art In automation equipment and various safety devices,
To ensure reliable operation, occurrence of accidents, and improvement of mobility,
The detection of an object to be processed and an object is indispensable, and as one of such detection devices for an object to be detected, there is a light reflection type object presence / absence detection device using light as a detection medium.

In FIG. 2, reference numeral 1 denotes a reflection type optical sensor, 2 denotes an object to be detected, the object 2 has a mirror-like surface, and the surface is the surface of the reflection type optical sensor 1. The detection object 2 is perpendicular to the optical axis and moves so as to block the optical axis of the reflection type optical sensor 1. Reference numeral 3 is a base of a device provided with the reflection type optical sensor 1, and the surface of the base 3 is a surface which does not reflect light or hardly reflects light.

When the object 2 to be detected is located at a position where it does not block the optical axis of the reflection type optical sensor 1 in FIG. 2, the detection light 4 emitted from the reflection type optical sensor 1 illuminates the base 3. As described above, since the surface of the base 3 is a non-reflective surface, the emitted detection light 4 is not reflected, the reflective optical sensor 1 does not detect reflected light, and the reflective optical sensor 1 The presence of the detected object 2 is not detected.

Next, when the object 2 to be detected interrupts the optical axis of the reflective optical sensor 1, the detection light 4 is reflected on the surface of the object 2 and the reflected light is reflected by the reflective optical sensor 1. To be detected. Thus, the reflective optical sensor 1 detects the presence of the detected body 2.

[0006]

However, in the above-described conventional object presence / absence detecting apparatus, when the detected object 2 has a large unevenness, or when the detected object 2 is a wafer manufactured by semiconductor manufacturing, the wafer surface is not exposed. The generated thin film causes light interference, and the reflected light is attenuated. Therefore, there is a case where the reflected light from the detected object 2 does not have an intensity that can be detected by the reflective optical sensor 1, and the certainty of the detection of the detected object 2 is poor. There was a problem such as the level setting was delicate.

In view of the above situation, the present invention aims to provide an object presence / absence detection device which can reliably detect an object to be detected and has high reliability or which can easily set a detection level.

[0008]

SUMMARY OF THE INVENTION The present invention is an object presence / absence detection device equipped with a reflection type optical sensor, wherein the optical axis of the reflection type optical sensor is non-perpendicular to the detection light irradiation surface of the object to be detected. And a reflector having a reflecting surface facing the reflective optical sensor and having a reflection surface perpendicular to the optical axis of the reflective optical sensor.

[0009]

When the object to be detected does not block the optical axis of the reflection type optical sensor, the detection light reflected by the reflector enters the reflection type optical sensor. Judge,
When the object to be detected blocks the optical axis of the reflective optical sensor, the reflected light does not enter the reflective optical sensor, and the reflective optical sensor detects the presence of the object.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the same parts as those shown in FIG. 2 are designated by the same reference numerals.

The reflection type optical sensor 1 is provided so that the optical axis is non-perpendicular to the reflection surface of the object to be detected 2, and the reflection type optical sensor 1 is opposed to the reflection type optical sensor 1 so that the reflection type optical sensor 1 has an optical axis. A reflector 5 having a vertical anti-slope is provided.

When the object 2 to be detected is located at a position where it does not block the optical axis of the reflection type optical sensor 1 in FIG. 2, the detection light 4 emitted from the reflection type optical sensor 1 illuminates the reflector 5. . The detection light 4 reflected by the reflector 5 enters the reflection type optical sensor 1 and the reflection type optical sensor 1 detects the absence of the detected body 2.

Next, when the detected body 2 blocks the optical axis of the reflection type photosensor 1, the detected light 4 is blocked by the detected body 2. Further, as described above, since the optical axis of the reflection type optical sensor 1 is non-perpendicular to the surface of the detected body 2, the optical axis of the detection light 4 reflected by the detected body 2 is the reflection type optical sensor. It does not match the optical axis of the sensor 1. Therefore, the reflected light does not enter the reflective optical sensor 1. The reflective optical sensor 1 is an object to be detected 2
Detect the presence of.

Since the object presence / absence detecting device does not detect the reflected light from the object 2 to be detected, the presence / absence of the object 2 to be detected can be reliably detected regardless of the property of the surface of the object 2 to be detected. You can do it. Further, the sensitivity adjustment of the reflective optical sensor 1 is performed by the reflector 5
The adjustment is simple, and the intensity of the reflected light changes each time the detected object 2 changes due to the surface properties and the perpendicularity of the reflected surface of the detected object 2. The uncertainty element is eliminated, and malfunction can be prevented.

[0016]

As described above, according to the present invention, the presence or absence of the detected object can be reliably detected regardless of the state of the detected object, and the detection accuracy and the detection reliability are improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 1 Reflective Optical Sensor 2 Detected Object 3 Base 4 Detected Light 5 Reflector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Tomita 3-14-20 Higashi-Nakano, Nakano-ku, Tokyo Inside Kokusai Electric Co., Ltd.

Claims (1)

[Claims] 1. An object presence / absence detection device comprising a reflective photosensor, wherein the optical axis of the reflective photosensor is non-perpendicular to the detection light irradiation surface of the object to be detected. An object presence / absence detection device, characterized in that a reflector having a reflecting surface facing each other and perpendicular to the optical axis of the reflection type optical sensor is provided.