US 11,722,137 B1
Variable-distance proximity detector
Mark Robert Lee, Edmonds, WA (US)
Assigned to Meta Platforms Technologies, LLC, Menlo Park, CA (US)
Filed by META PLATFORMS TECHNOLOGIES, LLC, Menlo Park, CA (US)
Filed on Sep. 29, 2021, as Appl. No. 17/488,874.
Claims priority of provisional application 63/087,091, filed on Oct. 2, 2020.
Int. Cl. H03K 17/955 (2006.01); G06F 3/044 (2006.01); H03K 17/945 (2006.01)
CPC H03K 17/955 (2013.01) [G06F 3/044 (2013.01); G06F 2203/04108 (2013.01); H03K 2017/9455 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a capacitive proximity sensor that increases capacitance in response to proximity of an object;
a reference capacitor in parallel with the capacitive proximity sensor;
a switch that connects and disconnects the capacitive proximity sensor and the reference capacitor; and
a capacitance sensing block that generates a capacitance signal based on a capacitance of the reference capacitor when the switch is in a disconnecting state and based on the capacitance of the reference capacitor and a capacitance of the capacitive proximity sensor when the switch is in a connecting state,
wherein the reference capacitor produces a baseline capacitance level beyond which capacitance sensed by the capacitance sensing block comprises capacitance from proximity of an object to the capacitive proximity sensor, and
wherein the baseline capacitance level is removed from the amount of capacitance sensed by the capacitance sensing block.