US 12,169,125 B2
Optical interferometry proximity sensor with temperature variation compensation
Mengshu Huang, Cupertino, CA (US); and James J. Dudley, Sunnyvale, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Jul. 12, 2023, as Appl. No. 18/221,210.
Application 18/221,210 is a continuation of application No. 16/230,967, filed on Dec. 21, 2018, granted, now 11,740,071.
Prior Publication US 2023/0366672 A1, Nov. 16, 2023
Int. Cl. G01B 9/02 (2022.01); G01N 15/1434 (2024.01); H01S 5/02257 (2021.01); H01S 5/026 (2006.01); H01S 5/183 (2006.01); G01N 15/10 (2006.01)
CPC G01B 9/02092 (2013.01) [G01N 15/1434 (2013.01); H01S 5/02257 (2021.01); H01S 5/0264 (2013.01); H01S 5/183 (2013.01); G01N 2015/1027 (2024.01); G01N 2015/1438 (2013.01); G01N 2015/1452 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A proximity sensor configured for detecting proximity of a user of a portable electronic device to the portable electronic device, the proximity sensor comprising:
a substrate;
a first laser light source disposed on a first region of the substrate;
a second laser light source disposed on a second region of the substrate adjacent to, and coplanar with, the first region;
an enclosure formed from a transparent material and positioned over the substrate to enclose the first laser light source and the second laser light source within the enclosure, the enclosure defining:
a lensing region aligned over the first laser light source such that light emitted by the first laser light source is refracted by the lensing region before exiting the enclosure to illuminate an object external to the proximity sensor; and
a planar reflection region aligned over the second laser light source such that light emitted by the second laser light source reflects from the planar reflection region and returns to the second laser light source to induce a self-mixing interferometric effect; and
a controller configured to drive the first laser light source and the second laser light source and to determine a distance to and a velocity of the object based on self-mixing induced in the first laser light source, output of the first laser light source calibrated based on the self-mixing interferometric effect induced in the second laser light source.