Patent ID: 7599117
Filing Date: 2009-10-06
Classification: G02B,G02F

Abstract:
1. A view angle control sheet comprising lens portions having trapezoidal shapes in section are arranged at predetermined intervals, a wedge-shaped portion between said lens portions adjacent to each other is filled with the same material as said lens portion or with a material different from said lens portion, said wedge-shaped portion has a bottom surface on a screen image source side while having a leading end on an observer side, and the following relationships hold: where Nx is a refractive index of a material constituting at least a slope portion of the wedge-shaped portion, Ny is a refractive index of a material constituting said lens portion, θ is an angle formed by the slope portion of the wedge-shaped portion and a normal line of a light beam outgoing plane, and Δn is a ratio (Nx/Ny) of said refractive index Nx to said refractive index Ny; a sectional shape of said wedge-shape portion has a wide bottom surface on the screen image source side; and a sectional shape of said lens portion has a wide lower base on the observer side, and the sectional shape of said lens has a narrow upper base on the screen image side.