Patent ID: 8334969
Filing Date: 2012-12-18
Classification: G01S

Abstract:
1. An optoelectronic sensor ( 10 ) for the measurement of distances or distance changes in accordance with the light transit time principle having a light transmitter ( 12 ) for the transmission of a light signal and having a light receiver ( 16 ) for the reception of the remitted or reflected light signal, wherein an evaluation unit ( 18 ) is provided which is made to fix the transmission time for the light signal relative to a reference time and to digitize the received light signal on a sampling pattern ( 108 ) having a sampling period to determine the reception time of the light signal, and wherein a time base unit ( 38 ) is provided by means of which the transmission time can be shifted relative to the sampling pattern ( 108 ) with a time precision below the sampling period, providing a time pattern with a time precision finer than the sampling pattern, wherein the time base unit ( 38 ) is made to derive the time shift of the transmission time from a first time signal having a first frequency (f 1 ) and a second time signal having a second frequency (f 2 ) different from the first frequency (f 1 ) and to provide any desired time shifts with a time resolution given by the difference period belonging to the first and second frequencies (f 1 , f 2 ) wherein the time base unit ( 38 ) selects and decouples a pair of nth period of the first frequency and nth period of the second frequency.