PURPOSE: To miniaturize constitution by making the primary power supply necessary for the discharge circuit of an APD (avalanche photodiode) and a flash lamp common.
CONSTITUTION: A flash lamp is allowed to emit light by a discharge circuit 1 to oscillate a solid-state laser oscillator 2 and transmission laser beam 11 is emitted to a target from a transmission optical system 3. The detected beam 13 reflected from the target is condensed to an APD 6 by a detection optical system 5 to be converted to an electric signal. A signal processor 8 converts a distance from a time lag on the basis of the start pulse signal 12 obtained from a part of the laser beam 11 by a start pulse generator 4 and the stop pulse 14 obtained from the output of the APD 6 by a stop pulse generator 7. The primary power supply of the circuit 1 and the charge power supply of the bias power supply 16 of the APD are set to a common primary power supply 15 and the power supply 16 is controlled by a temp. detection circuit 17 and the operation voltage of the oscillator 2 is made higher than that of the APD 6. By this method, the apparatus is miniaturized and the fluctuation of a measuring range due to the change of circumferential temp. is suppressed.
NORO KOHEI
HOZUMI YUJI
TOJO NAOYUKI
MORI AKIYOSHI
