To prevent erroneous detection due to periodically changing disturbance light such as from a fluorescent lamp in an object detection sensor for detecting presence/absence of an object by comparing a light receiving amount when a light emission element emits light and a light receiving amount when the light emission element does not emit light.
The object detection sensor includes the light emission element 1, a light receiving element 2, and determination means 3 for determining detection of the object by comparing the light receiving amount (A) when the light emission element emits light and the light receiving amount (B) when the light emission element does not emit light. In the object detection sensor, a length of time T1 for measuring the light receiving amount (A) and a length of time T1 for measuring the light receiving amount (B) are made equal and the length of time T1 is made integral multiple of a half cycle period of a commercial power source.
OGAWA YOSHIFUMI
OURA HIROYUKI
| JP2003296721A | 2003-10-17 |
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