US 11,940,293 B2
Finger devices with self-mixing interferometric proximity sensors
Mengshu Huang, Cupertino, CA (US); Ahmet Fatih Cihan, San Jose, CA (US); Adrian Z. Harb, San Jose, CA (US); Stephen E. Dey, San Francisco, CA (US); Yuhao Pan, Sunnyvale, CA (US); and Mehmet Mutlu, San Jose, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Sep. 2, 2021, as Appl. No. 17/465,594.
Prior Publication US 2023/0073039 A1, Mar. 9, 2023
Int. Cl. G01C 3/08 (2006.01); G01B 9/02 (2022.01); G01B 9/02097 (2022.01); G06F 3/01 (2006.01); G06F 3/03 (2006.01)
CPC G01C 3/08 (2013.01) [G01B 9/02092 (2013.01); G06F 3/014 (2013.01); G06F 3/016 (2013.01); G01B 9/02097 (2013.01); G06F 3/017 (2013.01); G06F 3/03 (2013.01); G06F 2203/0331 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A finger device configured to be worn on a finger of a user, comprising:
a housing configured to be coupled to the finger;
a self-mixing interferometric proximity sensor coupled to the housing that measures changes in a distance between the self-mixing interferometric proximity sensor and a side of the finger; and
control circuitry configured to determine a force of a touch input by the finger using the self-mixing interferometric proximity sensor, wherein the control circuitry is configured to operate the self-mixing interferometric proximity sensor according to a duty cycle where the self-mixing interferometric proximity sensor alternates between an on state in which the changes in the distance are measured and an off state in which the changes in the distance are not measured and wherein the control circuitry is configured to use interpolation to estimate changes in the distance between the self-mixing interferometric proximity sensor and the side of the finger during the off states.