Patent ID: 7978410
Filing Date: 2011-07-12
Classification: G02B

Abstract:
1. An optical sheet, comprising: a transparent base having a light-receiving surface and a light-exit surface opposite the light-receiving surface; a plurality of first micro structures disposed on the light-exit surface, wherein each of the first micro structures comprises: a first planar surface formed on the light-exit surface, the first planar surface having a first side and a second side substantially perpendicular to each other; and a curve surface opposite the first planar surface; and a plurality of second micro structures disposed on the light-receiving surface, wherein each of the second micro structures corresponds to one of the first micro structures and comprises: a second planar surface formed on the light-receiving surface, the second planar surface having a third side and a fourth side substantially perpendicular to each other, the third side being substantially parallel to the first side, and the length of the third side being equal to 20%-75% of the length of the first side, wherein each of the first micro structures forms a first orthogonal projection area on the light-receiving surface, each of the second micro structures corresponding to the first micro structure forms a second orthogonal projection area on the light-receiving surface, the second planar surface is located within the first orthogonal projection area, and the entire area of the second planar surface is equal to the second orthogonal projection area; and a total reflection surface connected with the second planar surface.