1
Timothy P Allen, David Gillespie, Robert J Miller, G√ľnter Steinbach: Object position detection system and method. Synaptics, Sierra Patent Group, May 29, 2001: US06239389 (269 worldwide citation)

A proximity sensor system includes a sensor matrix array having a characteristic capacitance on horizontal and vertical conductors connected to sensor pads. The capacitance changes as a function of the proximity of an object or objects to the sensor matrix. The change in capacitance of each node in ...


2
Edward N Evans: Detection of object in path of moving gate. Park Mobile, Larson Taylor & Hinds, June 23, 1981: US04274226 (23 worldwide citation)

Electromagnetic radiation object position detection system and method are disclosed for detecting when an object is located in the path of a powered sliding gate. In a preferred embodiment, polarized microwave radiation is emitted from a source fixed relative to the sliding gate. This radiation is p ...