Patent ID: 7568820
Filing Date: 2009-08-04
Classification: G02F

Abstract:
1. A light-controlling sheet for a planar light source part, for making light emitted from the planar light source part uniform, comprising: a lens part having a large number of unit lenses arranged in parallel, with a lens surface of each unit lens facing to a light-exiting side of said sheet, a cross section of the lens surface of each unit lens taken perpendicularly to a longitudinal direction of the unit lens being asymmetrical, wherein the lens surface of each unit lens has an upper surface part in the shape of part of an elliptical cylindroid surface, located on an upper side relative to a vertical direction which is parallel to a light incident side, and a lower surface part in the shape of part of an elliptical cylindroid surface, located on a lower side relative to the vertical direction, the upper surface part and the lower surface part are different in a vertical dimension, wherein the upper surface part is greater than the lower surface part in a vertical height taken in a direction in which the unit lenses are arranged in parallel and which is perpendicular to the longitudinal direction of the unit lens, and wherein the upper surface part and the lower surface part are convex with respect to the vertical direction.