| 摘要 |
<p>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.</p> |
