| CPC E05F 15/74 (2015.01) [G01V 8/20 (2013.01); E05F 2015/435 (2015.01)] | 20 Claims |
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1. A door sensor, comprising:
a first emitter configured to emit an emission beam comprising IR light during an emitting phase;
a lens configured to form an IR pattern on a surface by:
duplicating the emission beam to form a first duplicated beam and a second duplicated beam,
directing the first duplicated beam to a first reception area on the surface, the first reception area comprising the first duplicated beam and a third duplicated beam from a second emitter, and
directing the second duplicated beam to a second reception area on the surface;
a receptor configured to receive a reception beam from the first reception area, the reception beam comprising one or more of the first duplicated beam and the third duplicated beam reflected from the surface during a listening phase;
the receptor further configured to receive an interference beam transmitted from an adjacent door sensor during the listening phase; and
a controller operatively coupled to a memory storing computer-readable instructions that, when executed by the controller, cause the controller to:
determine one or more of a frequency and a phase of the interference beam,
determine whether the emitting phase should take precedence over the transmission of the interference beam, and
adjust a timing of one or more of the emitting phase and the listening phase to reduce interference from the interference beam.
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