Abstract: An infrared detector (301) is provided which comprises a pyroelectric detector (303) having first and second sensing elements (345), an aperture stop (311), and a Fresnel lens array (305). The detector may be used as a passive infrared sensor unit for detecting intrusion into large openings.
Abstract: An infrared detector (301) is provided which comprises a pyroelectric detector (303) having first and second sensing elements (345), an aperture stop (311), and a Fresnel lens array (305). The detector may be used as a passive infrared sensor unit for detecting intrusion into large openings.
Abstract: An aquatic device is provided which has a light-emitting surface. The device (101) is equipped with a light guide (105) adapted to adsorb light impinging on a first surface (113) of the device, and to emit light from a second surface (115) of the device.
Abstract: An infrared imaging device is provided which comprises first and second plastic Fresnel lenses that are in optical communication with each other. Each of the first and second lenses have a first major surface which is convex and a second major surface which comprises a Fresnel surface. The first lens is adapted to mimic a meniscus asphere correct for conjugates of infinity and for the focal length of said first lens, and the second lens is adapted to mimic a meniscus asphere and is further adapted to act as a field flattener.
Abstract: An infrared imaging device is provided which comprises first and second plastic Fresnel lenses that are in optical communication with each other. Each of the first and second lenses have a first major surface which is convex and a second major surface which comprises a Fresnel surface. The first lens is adapted to mimic a meniscus asphere correct for conjugates of infinity and for the focal length of said first lens, and the second lens is adapted to mimic a meniscus asphere and is further adapted to act as a field flattener.
Abstract: A passive infrared motion detector that creates a detection pattern with non-diverging insensitive zones. The sensing elements are of alternating polarity and each has a width w. An optical collection system directs infrared radiation onto the sensing elements. The sensing elements are separated by a distance equal to an integer multiple of width w, with the integer being at least two. The optical centers of the optical collection system are separated by an integer multiple of width w, with the integer being at least two. The arrangement of the optical centers and the sensing elements results in a detection pattern with non-diverging insensitive zones, with the insensitive zones having a negligible width.
Abstract: A microlens array is formed with lenses having many different symmetries to produce a large number of light output pattern shapes. The portions of the microlens array lenslets that direct light into undesirable locations are replaced with additional lenslets that redirect the light to where it is wanted. The microlens array has a plurality of primary lenslets on a substrate, the primary lenslets being curved shapes. Each of the primary lenslets has a surface area and a peripheral region. A plurality of secondary lenslets are at the peripheral regions of the primary lenslets and have surface areas which are smaller than the surface areas of the primary lenslets. The primary lenslets have a first vertical dimension and the secondary lenslets have a second vertical dimension which is smaller than the first vertical dimension. Tertiary lenslets may also be included in the microlens array. In the second of two described embodiments, the secondary and tertiary lenslets present convex cross-sectional shapes.
Abstract: A motion sensor has a pyroelectric detector, a Fresnel lens array, a reducing lens, and a housing. The detector has two elements located side-by-side and the lens array has a plurality of lenslets which are integrally formed. The reducing lens demagnifies the elements. The reducing lens has grooves which run in parallel directions and face toward the elements. The lens array illuminates the detector by focusing infrared light through the reducing lens and onto the elements. The reducing lens makes the elements appear smaller and closer together. The reduced image of the detector allows the lenslets to be spaced more closely than prior art lenslets, thereby making the angular separation less than the angular separation of prior art sensors. Alternatively, the detector housing may be made smaller while maintaining the same angular separation of prior art sensors. If an object moves between two zones, the sensor detects the movement and triggers an alarm, turns on a light, or initiates some other process.