Patent ID: 7411171

Claim:
A circuit arrangement for analyzing a clocked optical signal ( 3 a ′, 3 a ) reflected from an object ( 3 ′, 3 ), comprising at least one radiation emitter ( 1 ′, 1 ) which, for providing the clocked signal ( 1 a ′, 1 a ) is connected to a clocking signal generator ( 4 ′, 4 ), at least one radiation receiver ( 2 ′, 2 ) which receives radiation pulses ( 1 a ′, 1 a ) emitted by the radiation emitter ( 1 ′, 1 ) and reflected from the object ( 3 ′, 3 ), a controllable amplifier ( 6 ′, 6 ) having an input ( 6 E′, 6 E) connected to the clocking signal generator ( 4 ′, 4 ) and an output ( 6 A′ 6 A) connected to a controllable power source ( 9 ) for controlling the strength of the output signal provided by the radiation receiver ( 2 ′, 2 ), the circuit arrangement further comprising a comparator ( 5 ′, 5 , 12 , 13 , 14 , 15 ) by means of which output signal pulses ( 2 a ′, 2 a ) of the radiation receiver ( 2 ′, 2 ) are compared with reference signal pulses ( 6 a ′, 6 a ) of the controllable amplifier ( 6 ′, 6 ), wherein the amplitudes of the reference signal pulses ( 6 a ′, 6 a ) depend on output signals ( 5 a ′, 5 a ) of the comparator ( 5 ′, 5 , 12 , 13 , 14 , 15 ), the reference signal pulses ( 6 a ′, 6 a ) being generated internally and occurring concurrently with the radiation optical signal ( 3 a ′, 3 a ) received by the radiation receiver ( 2 ′, 2 ) and the output signal pulses ( 2 a ′, 2 a ) of the radiation receiver ( 2 ′, 2 ) are compensated for each by the respective internal reference signal pulses ( 6 a ′, 6 a ) before their analysis in the circuit arrangement.