Patent ID: 8648771

Claim:
A display device, comprising: a display panel comprising a central axis, a display area and a non-display area disposed outside the display area; an optical film disposed near one side of the display panel, the optical film comprising a microstructure configured to diverge the incident light into the display panel thereby a portion of the incident light near the border between the display area and the non-display area is redirected to travel over the non-display area; and a convex lens disposed near the other side of the display panel, the convex lens comprising a Fresnel structure and being configured to converge the output light from the display panel thereby the output light is redirected to travel approximately parallel to the central axis; wherein the microstructure comprising a plurality of first inclined surfaces is formed on a surface of the optical film facing away from the display panel and a planar surface is disposed on the other opposite surface of the optical film, and tilt angles θ f of the plurality of the first inclined surfaces are determined using the following equation: tan ⁢ ⁢ θ R = L F - A n air × sin ⁢ ⁢ θ R = n × sin ⁢ ⁢ θ 1 n air × sin ⁢ ⁢ θ i = n × sin ⁢ ⁢ θ 2 θ f = θ 1 + θ 2 where n air is the refractive index of air, n is the refractive index of the optical film, L is a distance measured between a location of light leaving the optical film and the central axis, F is the focal length of the convex lens, A is a distance between the optical film and the convex lens, θ i is a first incident angle of light entering the first inclined surface, θ 2 is a first refraction angle of light refracted through the first inclined surface, θ 1 is a second incident angle of light incident on the planar surface, and θ R is a second refraction angle of light refracted through the planar surface.