Fresnel lens

The utility model discloses a Fresnel lens, comprising a first lens part, a second lens part, a third lens part and a fourth lens part, which are integrated on a lens surface. Each lens part comprises a plurality of windows. According to the Fresnel lens of the utility model, the design of a multi-l...

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Bibliographic Details
Main Authors MA CHU, HUANG ZUHENG, LI WEIQIANG
Format Patent
LanguageChinese
English
Published 27.02.2013
Subjects
OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
OPTICS
PHYSICS
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Summary:The utility model discloses a Fresnel lens, comprising a first lens part, a second lens part, a third lens part and a fourth lens part, which are integrated on a lens surface. Each lens part comprises a plurality of windows. According to the Fresnel lens of the utility model, the design of a multi-layer combined lens is adopted, the focal distance is designed by adopting different lens in each layer, and the long-distance detection, the middle-distance detection and the close-distance detection are realized by changing the focal distance. Furthermore, blind areas of a detection area are reduced through mutual complementation of the multi-layer lens. Lights are gathered to the same point by adjusting the position of the optical center of the lens, so that the problem that an object to be detected moves towards the lens direction but can not be detected or can be detected only when moving to the very close distance. According to the Fresnel lens adopting the ultrathin wall design, the problems caused by great e
Bibliography:Application Number: CN20122134019U