Diffusion filmDiffusion film mainly refers to the backlight part applied to LCD module or covering the surface of LED light source to achieve the effect of light diffusion.When light passes through the diffusion layer with PET as the substrate, it will pass through the medium with different refractive index, causing many phenomena of refraction, reflection and scattering of light. It can be modified to become a uniform surface light source to achieve the effect of optical diffusion.It mainly plays a role in correcting the diffusion angle in the backlight structure, which will increase the light radiation area, but reduce the light intensity per unit area, that is, reduce the brightness. After the light source is diffused by the diffusion material, it can become a secondary light source with larger area, better uniformity and stable chromaticity. It has the function of diffusing light, that is, the light will scatter on its surface, spreading the light gently and evenly; The basic structure of most diffusion films is to coat optical astigmatic particles on transparent substrates such as PET on both sides.