Patent ID: 7186965

Claim:
A distance sensor for detecting a distance to an object point, comprising: an electromagnetic radiation source for irradiating the object point by a radiation pulse in an irradiation time window; a detector for detecting electromagnetic radiation reflected from the object point in a detection time window which is in a predetermined temporal relation to the irradiation time window, wherein the detector comprises: a photoelectrode for, in accordance with the external photoeffect, emitting photoelectrons responsive to the reflected electromagnetic radiation; and an electron detector for transforming the photoelectrons emitted to a detection signal indicating a quantity of the electromagnetic radiation reflected from the object point; and an evaluator for determining the distance to the object point from the detection signal, the detector further comprising: a counterelectrode which, together with the photoelectrode, forms a capacity; a connector for connecting the counterelectrode to a predetermined potential before the detection time window and for separating same from the predetermined potential during the detection time window such that the capacity is discharged during the detection time window; a connector for connecting the photoelectrode to ground during the detection time window and to the predetermined potential after the detection time window; and a reader for reading out a voltage across the capacity after the detection time window to obtain the detection signal.