Fresnel lens (flaky):

7601-15(72*50)

Focal length: 29MM

Distance: 18M

Angle: 110 degrees

(1) Assume that the refractive power of a lens only occurs on an optical surface (eg, a lens surface) and removes as much optical material as possible while preserving the curvature of the surface.

(2) The continuous surface portion of the Fresnel optical lens is "collapsed" onto a flat surface. Viewed from the cross-section, the surface consists of a series of zigzag grooves, the center of which is an elliptical arc. Each groove has a different angle from the adjacent groove, but it concentrates the light to form a central focus, which is the focus of the lens. Each groove can be seen as a separate lenslet that adjusts the light to parallel light or spotlight. This lens also eliminates partial spherical aberration.

2, Fresnel lens: also known as the threaded lens, mostly made of polyolefin sheet injection pressure sheet, but also made of glass, the lens surface is a glossy surface, the other side of the recording from small to large concentric circles, it The texture is designed based on the interference of light and the relative sensitivity and receiving angle requirements.