The core optical principle behind the light diffusion effect of LED lampshades is that when light passes through a diffusion layer made of substrates such as PC/PMMA/PS, it encounters a medium (diffusing particles) with a different refractive index, resulting in multi-angle and multi-directional refraction, reflection, and scattering, thus transforming a point light source into a uniform surface light source. Its optical basis follows the laws of reflection (the angle of incidence equals the angle of reflection) and refraction (the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant).
The development of LED lampshades is closely related to material advancements. In the early stages of LED lighting development, glass was used, but it was fragile and had poor light diffusion. Transparent resin was subsequently used, which, while having high transmittance, had unsatisfactory scattering effects and light source concealment. White board resin had the problem of excessively low transmittance. Ultimately, composite materials with specific light diffusion functions became the mainstream, balancing the requirements of high transmittance and good light source concealment.