US 11,715,321 B2
Geometric structures for acoustic impedance matching and improved touch sensing and fingerprint imaging
Daniel J. Hiemstra, San Francisco, CA (US); George Ho Yin Mak, Fremont, CA (US); Ehsan Khajeh, Los Gatos, CA (US); and Camille L. Everhart, Cupertino, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Apr. 22, 2022, as Appl. No. 17/660,308.
Claims priority of provisional application 63/188,123, filed on May 13, 2021.
Claims priority of provisional application 63/188,108, filed on May 13, 2021.
Claims priority of provisional application 63/188,114, filed on May 13, 2021.
Prior Publication US 2022/0366719 A1, Nov. 17, 2022
Int. Cl. G06V 40/13 (2022.01); G06F 3/041 (2006.01); G06F 3/043 (2006.01); G10K 11/02 (2006.01)
CPC G06V 40/1306 (2022.01) [G06F 3/0412 (2013.01); G06F 3/0436 (2013.01); G10K 11/02 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A touch sensing device, comprising:
a sensing plate having a first surface, a second surface opposite the first surface and a first acoustic impedance, the first surface configured for receiving one or more touches and the second surface formed with a plurality of geometric structures; and
one or more ultrasonic transducers having a second acoustic impedance different from the first acoustic impedance and configured for propagating ultrasonic waves through the sensing plate to the first surface;
wherein the plurality of geometric structures is between the first surface and the one or more ultrasonic transducers and taper from valleys to distal endpoints oriented towards the one or more ultrasonic transducers, the plurality of geometric structures configured for reducing an acoustic impedance mismatch between the one or more ultrasonic transducers and the sensing plate.