US 12,254,129 B2
Determining charge on a facial-tracking sensor
Charles Walter Boecker, Ames, IA (US); Jouya Jadidian, Los Gatos, CA (US); Barry Thompson, Menlo Park, CA (US); Niranjan Achugundla Puttaswamy, San Jose, CA (US); and Lawrence Albert Prather, Boulder Creek, CA (US)
Assigned to Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed by Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed on Jun. 28, 2022, as Appl. No. 17/809,520.
Prior Publication US 2023/0418368 A1, Dec. 28, 2023
Int. Cl. G06F 3/01 (2006.01); G01D 5/24 (2006.01)
CPC G06F 3/012 (2013.01) [G01D 5/24 (2013.01); G06F 3/013 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A head-mounted device, comprising:
a facial-tracking sensor comprising a sense capacitor electrode configured to be positioned proximate to a surface of a face and form a capacitance based upon a distance between the sense capacitor electrode and the surface of the face;
a controller configured to apply a reference voltage to the sense capacitor electrode, resulting in charge accumulating on the sense capacitor electrode in relation to the capacitance formed on the sense capacitor electrode; and
a charge sensing circuit comprising an integrator having a first input and a second input controllably connected to the sense capacitor electrode of the facial-tracking sensor, the charge sensing circuit being configured to determine an amount of the charge accumulated on the sense capacitor electrode, and to determine the capacitance of the sense capacitor electrode based upon the amount of the charge accumulated and the reference voltage.