Patent ID: 6157293
Filing Date: 2000-12-05
Classification: B60R,G01S,G01V

Abstract:
A device for detecting movement within a defined interior space, the device comprising:a transmitter transmitting an ultrasound beam into a defined interior;a sensor for sensing a reflection of the ultrasound beam and outputting an output signal representative of the reflected beam;a processor connected to said sensor for processing the signal in order to detect movement in the interior space;means for directing a transmitting direction of the ultrasound beam of said transmitter;means for directing a sensing direction of said sensor for improving a signal to noise ratio of the output signal of said sensor, said means for directing the sensing direction formed to orient the sensing direction of said sensor in dependence of the transmitting direction, the dependence being adjusted to minimize an influence of strayed reflected beams on the signal output by said sensor; anda direction detector for detecting the transmitting direction and the sensing direction, respectively, said direction detector being connected to said transmitter and said sensor for slaving the sensing direction according to the sensing direction.