Patent ID: 7553050
Filing Date: 2009-06-30
Classification: F21V,G02B,G02F

Abstract:
1. An optical sheet comprising: a base film; and a light-concentrating member including a plurality of light-concentrating protrusions disposed on an upper surface of the base film, each of the light-concentrating protrusions including: a first surface curvedly extended from the upper surface of the base film about a first central axis disposed substantially parallel to a first direction along the upper surface; a second surface substantially facing the first surface, and curvedly extended from the upper surface of the base film about a second central axis substantially parallel to the first central axis; and a third surface, which connects the first surface with the second surface, curvedly extended from the upper surface of the base film about a third central axis substantially perpendicular to the first and second central axes, the third surface convexly connected with both the first surface and the second surface; and a fourth surface substantially facing the third surface, and curvedly extended from the upper surface of the base film about a fourth central axis substantially parallel to the third central axis, the fourth surface connecting the first surface with the second surface, and the fourth surface convexly connected with both the first surface and the second surface wherein the first, second, third, and fourth surfaces respectively have a substantially triangular shape and have a common point.