Optical motion sensor

Abstract

In order to provide an optical motion sensor that can easily and effectively detect the movement of people in widely differing brightness conditions with a relatively simple circuit configuration, a light-receiving element (15) and a voltage equalization circuit (21) are connected in series, and the connection point between the light-receiving element (15) and the voltage equalization circuit (21) is connected to a signal output terminal (39) via a differential amplifier circuit (31) and a pulse-forming circuit (37) to constitute the circuit. The voltage equalization circuit comprises an emitter earth transistor, a capacitor that is inserted between the base and emitter of this transistor, and a resistor inserted between the base and collector of this transistor, and the collector of the transistor is connected to the light-receiving element.

Description

technical field [0001] The present invention relates to an optical motion sensor that detects motion in front of the sensor through a light receiving element. Background technique [0002] At present, people often use light-receiving elements such as photodiodes and phototransistors to detect the movement of people and objects. For example, in Patent Document 1, Japanese Patent Laid-Open No. 10-274517 proposes a fixed detection device, which can detect the movement of an object in a wide range, and can detect the direction of movement. [0003] In addition, there are also optical communication receivers using light receiving elements such as photodiodes. For example, in Patent Document 2, Japanese Unexamined Patent Publication No. 11-186971 proposes a light receiver, on which a plurality of amplification devices with different amplification ratios are arranged, and the light receiving intensity of the light receiving element is detected by means of intensity monitoring, and...

AI Technical Summary

Problems solved by technology

[0008] Therefore, if the detection sensitivity of the photoelectric sensor is set based on the indoor brightness without sunlight entering, the detection value of the sensor will enter a saturated state when sunlight enters the room during the day, and it is impossible to detect human movements, etc.

On the other hand, if the detection sensitivity of the photoelectric sensor is set for use in a bright room in consideration of sunlight, the detection sensitivity will decrease when you are indoors at night, and the working status of the sensor will sometimes be inaccurate.

[0009] Moreover, if considering the luminosity difference between day and night, a plurality of amplification circuits with different amplification ratios are provided, and the sensor can switch the amplification circuits, it can be used as a motion sensor installed on a simple indoor device only to detect human activities. , the circuit structure of this sensor is too complicated, which is a shortcoming

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