DRIVE CIRCUIT FOR OPTICAL TYPE SENSOR

摘要

PURPOSE: To provide the drive circuit of an optical sensor which is constituted to automatically regulate an amount of light emitted from a light emission element and form a device in a compact manner and stably maintain detecting sensitivity of the sensor. CONSTITUTION: The drive circuit of an optical type sensor has a variable resistance part 8 and by changing the resistance value of the variable resistance part 8, a voltage applied on a light emission element 9 is changed to control a light emission amount. Based on the output voltage of a light receiving element 8 detected by an output detecting part, the resistance value of the variable resistance part 8 is changed by a computer. The variable resistance part 8 comprises a plurality of resistance parts R0-R7 having respective different resistance values; and a resistance switching part 7 connecting in a switching manner a part of a plurality of the resistance parts R0-R7 to the light emission element 9, and switching is effected by an output input interface part 7a.