| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the light emitting part driving method of a reflection type photosensor which can surely detect a detection object by a simple constitution, when a reflected light to be detected is weak. SOLUTION: A reflection type photosenser 10 consists of the following; a light emitting part 11 constituted of a light emitting diode LED, a driving circuit 13 for driving the light emitting part by a transmitting pulse, a light receiving part 12 which is arranged in the vicinity of the light emitting part and receives the reflected light of a light outputted from the light emitting part, and a processing circuit for processing a detection signal from the light receiving part. In this case, the driving circuit 13 drives the light emitting element LED by a pulse modulation signal, as a transmission pulse, which is constituted by superposing a carrier pulse on a signal pulse for turning on the light emitting element LED in the light emitting part.</p> |
