| 摘要 |
<p>PURPOSE:To provide an obstacle sensing device which is less restrictive for the sensible range and is safe even for a person by furnishing a drive voltage control circuit to control the voltage of drive pulses to be impressed on a light emitting element, and controlling the transmitted light powers in different angular directions individually. CONSTITUTION:From a light sending device 1 a plurality of angular directions and pulse beams are generated, and the distance from an object concerned is sensed on the basis of the time difference between beam sending-off and reception of the reflected light. The arrangement includes a steering wheel angle sensor 8 to sense the angle of the steering wheel of car and a car speed sensor 9 to sense the car speed. The charging voltages of capacitors 12a-12n are controlled by controlling the current feed times for transistors 14a-14n with drive voltage control circuits 11a-11n in conformity to the input signal. Thereby the sent-off light powers from laser diodes 16a-16n can be increased or decreased in individual directions of projection angle. This increment or decrement of the power can be achieved simply by reducing the power, widening the light emitting interval, or widening the spreading angle of each beam.</p> |
