Abstract: 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.

Abstract: A non-planar Fresnel reflector array mold pattern and fabrication method are described which can be utilized to manufacture integral non-planar Fresnel reflector arrays which are not subject to molding inclusions. The Fresnel reflector segments comprising the mold pattern are joined at angles to one another and incorporate off-axis Fresnel segments at segment positions in which the optical axis of the segment is not sufficiently parallel to the intended pull direction of the associated mold. The focal point of each off-axis segment lies along a path that is angularly offset from the optical axis of said segment. The use of properly oriented off-axis Fresnel segments within the non-planar Fresnel array result in the elimination of molding inclusions. The mold pattern thus created may be positive or negative, and provides the three-dimensional pattern from which the final manufacturing molds or tools are created.

Abstract: A non-planar Fresnel reflector array mold pattern and fabrication method are described which can be utilized to manufacture integral non-planar Fresnel reflector arrays which are not subject to molding inclusions. The Fresnel reflector segments comprising the mold pattern are joined at angles to one another and incorporate off-axis Fresnel segments at segment positions in which the optical axis of the segment is not sufficiently parallel to the intended pull direction of the associated mold. The focal point of each off-axis segment lies along a path that is angularly offset from the optical axis of said segment. The use of properly oriented off-axis Fresnel segments within the non-planar Fresnel array result in the elimination of molding inclusions. The mold pattern thus created may be positive or negative, and provides the three-dimensional pattern from which the final manufacturing molds or tools are created.

Abstract: An infrared intrusion sensing system comprises a compound lens having a plurality of lines of focus for focusing infrared radiation that enters the system onto a detector, and a window to allow infrared radiation to enter the system and then be focused onto the detector by a set of curvilinear-shaped mirrors. The detector is located near the focal point of the compound lens elements and curvilinear-shaped mirror elements. An enclosure surrounding the detector provides isolation from insect entry and constitutes an insect exclusion enclosure envelope. The enclosure envelope is a protective volume of space for the optical paths between the lens or window and the detector that prevents the entry of objects about 1 mm in diameter or larger which could interfere with the optical paths.