Prism Film

Prism film is a micro-structured optical film used in backlight assemblies for LCD displays. It features a precise array of microscopic prismatic ridges (typically 90-degree angles) on one surface that refract and redirect light from the light guide plate toward the viewer. This optical manipulation increases on-axis luminance, improves viewing angle performance, and enhances overall display brightness efficiency by 1.5-2 times compared to systems without prism films. The film works in conjunction with other optical layers like diffuser films and reflective sheets to create uniform illumination across the display surface.

Prism films operate on the principle of total internal reflection and light redirection. When light from the backlight enters the film at various angles, the prism structures refract and redirect the light rays toward the normal viewing direction. The microscopic prism arrays (typically with pitch between 24-50μm) bend off-axis light through Snell's Law of refraction, concentrating luminance within the desired viewing cone while minimizing light loss through absorption or scattering.