Transmit beamforming of a two-dimensional array of ultrasonic transducers

A non-transitory computer-readable storage medium comprising instructions which when executed on one or more data processors, cause the one or more data processors to perform a method for transmit beamforming of a two-dimensional array of ultrasonic transducers, the method comprising:

• defining a beamforming pattern to apply to a beamforming space of the two-dimensional array of ultrasonic transducers, wherein the beamforming space comprises a plurality of elements, wherein each element of the beamforming space corresponds to an ultrasonic transducer of the two-dimensional array of ultrasonic transducers, wherein the beamforming pattern identifies which ultrasonic transducers within the beamforming space are activated during a transmit operation of the two-dimensional array of ultrasonic transducers, and wherein at least some of the ultrasonic transducers that are activated are phase delayed with respect to other ultrasonic transducers that are activated such that a generated ultrasonic beam is focused to a contact surface of a platen overlying the two-dimensional array of ultrasonic transducers for reflecting off an object in contact with the contact surface;
• applying the beamforming pattern simultaneously to a plurality of positions within the two-dimensional array of ultrasonic transducers;
• and
• performing a transmit operation by activating the ultrasonic transducers of the beamforming space within each of the plurality of positions according to the beamforming pattern such that a plurality of ultrasonic beams are generated simultaneously at the plurality of positions, wherein the plurality of ultrasonic beams are focused to the contact surface of the platen overlying the two-dimensional array of ultrasonic transducers.

A ultrasonic sensor comprising:

• a two-dimensional array of ultrasonic transducers;
• a memory;
• and
• a processor coupled to the memory and the two-dimensional array of ultrasonic transducers, the processor configured to:
• define a beamforming pattern to apply to a beamforming space of the two-dimensional array of ultrasonic transducers, wherein the beamforming space comprises a plurality of elements, wherein each element of the beamforming space corresponds to an ultrasonic transducer of the two-dimensional array of ultrasonic transducers, wherein the beamforming pattern identifies which ultrasonic transducers within the beamforming space are activated during a transmit operation of the two-dimensional array of ultrasonic transducers, and wherein at least some of the ultrasonic transducers that are activated are phase delayed with respect to other ultrasonic transducers that are activated such that a generated ultrasonic beam is focused to a contact surface of a platen overlying the two-dimensional array of ultrasonic transducers for reflecting off an object in contact with the contact surface;
• apply the beamforming pattern simultaneously to a plurality of positions within the two-dimensional array of ultrasonic transducers;
• and
• perform a transmit operation at the plurality of positions within the two-dimensional array of ultrasonic transducers by activating the ultrasonic transducers of the beamforming space within each of the plurality of positions according to the beamforming pattern such that a plurality of ultrasonic beams are generated simultaneously at the plurality of positions, wherein the plurality of ultrasonic beams are focused to the contact surface of the platen overlying the two-dimensional array of ultrasonic transducers.