Patent ID: 8508690

Claim:
An optical element for condensing or diffusing light which is incident from a light source through a light guide plate comprising: a light-transmitting base film including a plurality of diffusing cavities formed in one surface of the base film to diffuse light entering the base film and a light-condensing pattern with a plurality of light-condensing protrusions formed in the surface between adjacent diffusing cavities so as to condense incident light, wherein each of the plurality of light-condensing protrusions has two or more oblique light-condensing surfaces which are not parallel to each other, wherein the plurality of diffusing cavities are arranged in a first direction and a second direction with a given distance from each other, and the first direction is substantially perpendicular to the second direction, wherein each of the diffusing cavities have a hemispherical curved surface and the diameter of the diffusing cavities is greater than the width of the light-condensing protrusions, wherein the diffusing cavities has a ratio of a diameter to a depth ranging from 1:0.05 to 1:5.