The main function of the Fresnel lens is to focus and divide the detection area into several Ming and dark areas, and make the mobilizer body function entering the detection area generates a change in the infrared signal on PIR in the form of temperature changes.

Fresnel lens, also known as thread lens, was invented by French physicist Augustin Fresnel. The surface of this lens is the light surface, and the other side is burned from small to large -hearted round patterns. ‌ these patterns are designed with the principle of interference and diffraction of light, and ‌ are designed according to the relative sensitivity and receiving angle. Fresnel lens can make the light from the light sources gathered, and the efficiency of the lighting is improved, thus generating greater light strength.The role of this lens is not limited to improving the range of lighting, but also is widely used in many fields, including but not limited to projection display, ‌ conservation agglomeration, and solar utilization.

In the solar field, the application of Fresnel lens is particularly significant. It can effectively focus on sunlight, thereby improving the utilization rate and conversion efficiency of solar energy. The implementation of this lens is to simulate a large -diameter reflex parabolic surface, ‌ to achieve reflection and convergence of ray function.Through precise processing technology and technology, Fresnel lenses can achieve the large -scale, flat, thin and lightness of the lens, and maintain excellent optical properties at the same time. This lens not only plays a role in the field of solar heat use, but also shows its unique advantages in the fields of concentrated heating,  solar hydrogen -making, high -power concentration power generation.

In addition, the production and processing of Fresnel lenses involve extensive precision processing technology and process materials. At present, there are not many companies that can process large -sized Fresnel lens molds and products for more than 1 meter. The processing technology of larger size and high -precision Fresnel lens is an international problem.This has great practical significance for the application of China's relevant optical field.