Patent ID: 6717170
Filing Date: 2004-04-06
Classification: G01S

Abstract:
An optoelectronic apparatus for detecting objects in a monitored region comprising:a transmitter that emits transmission light that is guided into the monitored region, the emitted transmission light being in the form of a sequence of transmission light pulses; a diverting unit that periodically guides transmission light pulses into the monitored region; means for coupling out a portion of the light quantity of a transmission light pulse as a reference transmission light pulse so that for each diversion of a transmission light pulse by the diverting unit, a reference transmission light pulse is coupled out of the transmission light pulse; a receiver that receives reflected light including transmission light pulses reflected by an object in the monitored region and respective reference transmission light pulses which are guided by way of a reference path to the receiver; a housing having an exit window wherein the transmitter, the receiver and the diverting unit are situated in the housing so that the transmission light pulses diverted at the diverting unit are guided into the monitored region by way of the exit window; and wherein the coupling-out means is a reflection surface disposed at the exit window, the reflection surface reflecting a portion of the light quantity of the transmission light pulses as the reference transmission light pulse back to the receiver; and an evaluation unit connected to the transmitter and the receiver, said evaluation unit determining transit time tO of the reflected transmission light pulse, and transit time tR of the respective, reference transmission light pulse guided as a reference reflected light pulse to the receiver, wherein the transit-time difference toâˆ’tR is used to determine the distance of an object.