Operation of an ultrasonic sensor

Abstract

In a method of using an ultrasonic sensor comprising a two-dimensional array of ultrasonic transducers, a plurality of ultrasonic signals are transmitted according to a beamforming pattern at a position of the two-dimensional array. The beamforming pattern focuses the plurality of ultrasonic signals to location above the two-dimensional array, wherein the beamforming pattern identifies ultrasonic transducers of the two-dimensional array that are activated during transmission of the ultrasonic signals, and wherein at least some ultrasonic transducers of the beamforming pattern are phase delayed with respect to other ultrasonic transducers of the beamforming pattern. At least one reflected ultrasonic signal is received at the position according to a receive pattern, wherein the receive pattern identifies at least one ultrasonic transducers of the two-dimensional array that is activated during the receiving. The transmitting and the receiving are repeated at a plurality of positions of the two-dimensional array.

What is claimed is: 
     
         1 . A method of using an ultrasonic sensor comprising a two-dimensional array of ultrasonic transducers, the method comprising:
 at a position of the two-dimensional array of ultrasonic transducers:
 transmitting a plurality of ultrasonic signals according to a beamforming pattern, wherein the beamforming pattern focuses the plurality of ultrasonic signals to location above the two-dimensional array of ultrasonic transducers, wherein the beamforming pattern identifies ultrasonic transducers of the two-dimensional array of ultrasonic transducers that are activated during transmission of the ultrasonic signals, and wherein at least some ultrasonic transducers of the beamforming pattern are phase delayed with respect to other ultrasonic transducers of the beamforming pattern; and 
 receiving at least one reflected ultrasonic signal according to a receive pattern, wherein the receive pattern identifies at least one ultrasonic transducers of the two-dimensional array of ultrasonic transducers that is activated during the receiving; and 
   repeating the transmitting and the receiving at a plurality of positions of the two-dimensional array of ultrasonic transducers.