| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optical sheet exhibiting an excellent light collecting function. <P>SOLUTION: The optical sheet 30 has a body part 35, and a plurality of unit lenses 38 having a light diffusion function. The following Expression (2) is satisfied: (La(x)/La(0))≤(Lb(x+ϕ)/Lb (ϕ)), where La(θ) represents a brightness distribution when emitting a unit light beam advancing along a normal direction nd from each unit lens toward an apex part 41a of each unit lens, Lb(θ) represents a brightness distribution when emitting the unit light beam advancing along the normal direction from each unit lens toward an end part 41b of each unit lens, andϕrepresents an emission angle when emitting the unit light beam advancing along the normal direction from each unit lens toward the end part, on the assumption that each unit lens has no light diffusion function. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
