Wide angle pyroelectric infrared Fresnel lens

Abstract

The invention relates to the technical fields of burglar alarm and optical illumination, and provides a wide angle pyroelectric infrared fresnel lens on an infrared detector or an automatic infrared induction lighting optical component. The wide angle pyroelectric infrared Fresnel lens is composed of four layers, wherein a single lens is as a unit to detect an angle and distance, and each layer which is composed of a plurality of single lenses respectively detects different distance and different angles. Lenses of each layer use a different focal length design and a staggered arrangement mode, the fresnel lens refraction principle and an actual used method are used, pyroelectric infrared rays which pass through each of the single lens are focused on a same position, simultaneous detection of a stereo type detecting area which is formed by large distance, medium distance, short distance, very short distance and a wide angle is achieved, and thus blind zones in the detection area are reduced. In addition, the wide angle pyroelectric infrared Fresnel lens generates displacement of a focal position through changing a mode of an incident infrared ray angle, and thus detection distance is changed.

Description

technical field [0001] The invention belongs to an optical element, in particular to a wide-angle pyro-infrared Fresnel lens used in the technical fields of anti-theft alarm products and optical lighting products. Background technique [0002] The Fresnel lens is based on the ordinary circular convex lens "collapsing" onto a plane with equal tooth depth and equal tooth pitch according to the continuous surface part of the lens, forming a Fresnel lens equivalent to the ordinary lens. Both are based on the principle of optical refraction produced by light passing through the interface of different materials, and the light is adjusted into parallel light or concentrated light. [0003] Fresnel lenses are used in many technical fields, using various materials and processing methods. In the field of infrared detection; it is usually made of polyethylene material by injection molding. Its functions are: one is the focusing function, which focuses the pyro-infrared light into a po...

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Problems solved by technology

[0008] The purpose of the embodiments of the present invention is to provide a wide-angle pyro-infrared Fresnel lens used in passive infrared detectors for anti-theft alarm products and automatic infrared induction lamps for optical lighting products, aiming to solve the problem of using anti-theft alarm and optical lighting products in the existing domestic market. Th...

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