Optical motion sensor with elongated detection zone and method for elongating detection zone in an optical motion sensor

摘要

Apparatus and methods are described for extending the detection zone of an optical detection assembly, such as for a motion detector, along an axis without adding additional reflectors or circuitry. The optical detector within the optical detector assembly is positioned astigmatically, off-axis, in relation to an optically curved reflector from which it receives reflected radiation. Electromagnetic radiation incident on the optically curved reflector from an off-axis, astigmatic, beam area is directed to the optical detector to extend the detection area of the motion detector, or other system, along one axis when compared to on-axis detector positioning. By way of example, the optical detection assembly is configured with a pyroelectric detector positioned facing an optically curved mirror comprising a Fresnel reflector at a distance roughly equivalent to the focal length of the optically curved reflector. The resultant infrared motion detector provides an extended detection area along one axis.