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公开(公告)号:US20230126320A1
公开(公告)日:2023-04-27
申请号:US17970903
申请日:2022-10-21
IPC分类号: G01S7/41 , G01S7/4865 , G01N21/95
摘要: A motion detector (1) for a security system includes a primary sensing system including a PIR sensor (5) configured to detect movement of a person within a monitored environment (2), and an ancillary sensing system including a first emitter (7), a second emitter (8) and a receiver (9) configured to detect masking of the primary sensing system. Masking by an object (10) in the monitored environment (2) is determined using the first emitter (7) and the receiver (9) based on a time-of-flight of an optical signal emitted into the monitored environment (2) and reflected by the object (10). Masking by obscuring of a window (4) of the motion detector (1) is determined using the second emitter (8) and the receiver (9) based on the intensity of light transmission from the second emitter (8) through the window (4) to the receiver (9).