View angle control sheet and display device
AssigneeDai Nippon Printing Co., Ltd.
InventorMasahiro Goto
Life of this patent
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AssigneeDai Nippon Printing Co., Ltd.
InventorMasahiro Goto
Estimating the term…
A view angle control sheet having a wide view angle, in which diffuse light from a screen image source is effectively utilized to suppress a decrease in screen brightness while a decrease in image contrast caused by an outside light beam is suppressed to prevent generation of a ghost to improve contrast. The lens portions have trapezoidal shapes in section arranged at predetermined intervals. A wedge-shaped portion between the lens portions has a bottom surface on a screen image source side while having a leading end on an observer side, and the following relationships hold: Nx £ Ny and −0.01<Dn−cos q<0.002, 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 the lens portion, and Dn is a ratio (Nx/Ny).
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:
Dependencies are inferred from the claim text.