In general, the Fresnel lens are cut in spherical surface shape in order to minimize the optical aberration of the image during imaging. The lens can better calibrate the ideal point light source into a parallel light source.
In real life, no light source is a real point light source. However, solid state luminaries such as LED are very small, so as long as the distance between the lens and LED is appropriate, it can be used as a point light source. Therefore, the Fresnel lens can calibrate the LED output light into parallel light.
The traditional incandescent light source produces a lots of radiant heat, which limits the application of plastic optical materials in very close proximity to the light source.
Since most of the heat generated by LED is conductive, it is easier to use plastic optical lenses.
When it is necessary to calibrate the beam source of an LED luminaries into one with a wider angle range, the most common practice is to use a reflector combined with a Fresnel lens to reduce the amount of optical components used.
Fresnel lens is used in LED light distribution, which can increase the light effect and improve the brightness. Relative to the same lens and LED lamp, the focal length is different, and the emitting light angle can be set arbitrarily. Single lamp or multiple array LED lamp can be designed according to the requirements. Now it has been widely used in LED projection light, colorful projection light, floodlight, landscape light, signal light and various kinds of lamps.
Advantages of Fresnel lans:
1. Adopting high precision original mould, the product has high precision and good quality.
2. The product has ultra-thin structure, super-large size and ultra-light weight.
3. The shape of the product can be cut arbitrarily to meet the nuances variation of different customers and different products.
Compared with the traditional lens, Fresnel lens has the advantages of large area, light weight, low price, portablility and so on. It is a widely used optical element, and its design and manufacture involve many technical fields, including optical engineering, polymer material engineering, CNC machining, diamond turning technology, nickel plating technology, molding, injection molding, casting and other manufacturing processes. Therefore, the design, development and production of large-scale and high-precision Fresnel lens has become the main direction of technical development of production departments at home and abroad.