Image generation in an electronic device using ultrasonic transducers

1. A method for generating an image, the method comprising:

capturing a first set of image pixels by an ultrasonic sensor comprising an array of ultrasonic transducers using a first beamforming pattern, wherein the first beamforming pattern comprises a first pattern of transmit signals routed to a plurality of ultrasonic transducers of the ultrasonic sensor, wherein the first beamforming pattern activates transducers with different signal delays, to focus each beam to a single point over the ultrasonic sensor;

capturing a second set of image pixels by the ultrasonic sensor using a second beamforming pattern, wherein the second beamforming pattern comprises a second pattern of transmit signals routed to the plurality of ultrasonic transducers, wherein the second beamforming pattern is different than the first beamforming pattern, wherein the second beamforming pattern activates different transducers with different signal delays, to focus each beam to a single point over the ultrasonic sensor, and wherein the second set of image pixels corresponds to a different region of the ultrasonic sensor than the first set of image pixels; and

combining the first set of image pixels and the second set of image pixels to form the image.

2. The method of claim 1 , wherein the first set of image pixels and the second set of image pixels are non-overlapping pixels.

3. The method of claim 2 , wherein the combining the first set of image pixels and the second set of image pixels to form the image comprises:

adding the first set of image pixels to the second set of image pixels to form the image.

4. The method of claim 3 , wherein the method further comprises:

capturing a third set of image pixels by the ultrasonic sensor using a third beamforming pattern, the third beamforming pattern comprising a third pattern of transmit signals routed to the plurality of ultrasonic transducers, wherein the third beamforming pattern is different than the first and second beamforming patterns;

wherein the method further comprises combining the first set of image pixels, the second set of image pixels, and the third set of image pixels to form the image.

5. The method of claim 4 , wherein the method further comprises:

capturing at least one additional set of image pixels by the ultrasonic sensor using at least one additional beamforming pattern, each additional beamforming pattern comprising a pattern of transmit signals routed to the plurality of ultrasonic transducers, wherein each additional beamforming pattern is different than the first, second, and third beamforming patterns;

wherein the method further comprises combining the first set of image pixels, the second set of image pixels, the third set of image pixels and each additional set of image pixels to form the image.

6. The method of claim 4 , wherein the second pattern of ultrasonic transducers occupies a first pixel pattern and the third pattern of ultrasonic transducers occupies a second pixel pattern.

7. The method of claim 1 , wherein the combining the first set of image pixels and the second set of image pixels to form the image comprises:

replacing pixels of the first set of image pixels corresponding to the different region with the second set of image pixels to form the image.

8. The method of claim 7 , wherein the method further comprises:

capturing a third set of image pixels by the ultrasonic sensor using a third beamforming pattern, the third beamforming pattern comprising a third pattern of ultrasonic transducers, wherein the third beamforming pattern is different than the first and second beamforming patterns;

wherein the method further comprises combining the first set of image pixels, the second set of image pixels, and the third set of image pixels to form the image such that the second set of image pixels and third set of image pixels replaces some pixels of the first set of image pixels.

9. The method of claim 1 , wherein the ultrasonic sensor comprises a number of blocks of ultrasonic transducers.

10. The method of claim 9 , wherein pixels for the blocks of ultrasonic transducers are captured in parallel.

11. An electronic device comprising:

an ultrasonic sensor;

a processing logic module; and

a processor connected to the processing logic module and configured to perform the steps of:

capturing a first set of image pixels by an ultrasonic sensor comprising an array of ultrasonic transducers using a first beamforming pattern, wherein the first beamforming pattern comprises a first pattern of transmit signals routed to a plurality of ultrasonic transducers of the ultrasonic sensor, wherein the first beamforming pattern activates transducers with different signal delays, to focus each beam to a single point over the ultrasonic sensor,

capturing a second set of image pixels by the ultrasonic sensor using a second beamforming pattern, wherein the second beamforming pattern comprises a second pattern of transmit signals routed to the plurality of ultrasonic transducers, wherein the second beamforming pattern is different than the first beamforming pattern, wherein the second beamforming pattern activates different transducers with different signal delays, to focus each beam to a single point over the ultrasonic sensor, and wherein the second set of image pixels corresponds to a different region of the ultrasonic sensor than the first set of image pixels, and

combining the first set of image pixels and the second set of image pixels to form an image.

12. The electronic device of claim 11 , wherein the first set of image pixels and the second set of image pixels are non-overlapping pixels.

13. The electronic device of claim 11 , wherein the ultrasonic sensor comprises a number of blocks of ultrasonic transducers.

14. The electronic device of claim 13 , wherein image pixels for the blocks of ultrasonic transducers are captured in parallel.

15. The electronic device of claim 11 , wherein beamforming patterns activate different transducers with different signal delays, to focus each beam to a single point on the ultrasonic sensor.

16. A method of generating an image of a fingerprint with a fingerprint sensor comprising an ultrasonic sensor comprising a plurality of ultrasonic transducers to transmit a first ultrasonic beam from sets of ultrasonic transducers toward a surface configured to receive a finger having the fingerprint thereon and to receive a second ultrasonic beam reflected from the fingerprint, the second ultrasonic beam to generate a signal for processing in a signal processor, the method comprising:

capturing a first set of image pixels by an ultrasonic sensor comprising an array of ultrasonic transducers using a first beamforming pattern, wherein the first beamforming pattern comprises a first pattern of transmit signals routed to a plurality of ultrasonic transducers of the ultrasonic sensor;

capturing a second set of image pixels by the ultrasonic sensor using a second beamforming pattern, wherein the second beamforming pattern comprises a second pattern of transmit signals routed to the plurality of ultrasonic transducers, wherein the second beamforming pattern is different than the first beamforming pattern, and wherein the second set of image pixels corresponds to a different region of the ultrasonic sensor than the first set of image pixels; and

combining the first set of image pixels and the second set of image pixels to form the image.

17. The method of claim 16 , wherein the first set of image pixels and the second set of image pixels are non-overlapping pixels.

18. The method of claim 17 , wherein the combining the first set of image pixels and the second set of image pixels to form the image comprises:

adding the first set of image pixels to the second set of image pixels to form the image.

19. The method of claim 16 , wherein the combining the first set of image pixels and the second set of image pixels to form the image comprises:

replacing pixels of the first set of image pixels corresponding to the different region with the second set of image pixels to form the image.

20. The method of claim 16 , wherein the method further comprises:

capturing a third set of image pixels by the ultrasonic sensor using a third beamforming pattern, the third beamforming pattern comprising a third pattern of transmit signals routed to the plurality of ultrasonic transducers, wherein the third beamforming pattern is different than the first and second beamforming patterns;

wherein the method further comprises combining the first set of image pixels, the second set of image pixels, and the third set of image pixels to form the image such that the second set of image pixels and third set of image pixels replaces some pixels of the first set of image pixels.