| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that a duty ratio becomes small when large-angle incident light is tried to be deflected to a normal direction of a screen in the conventional total reflection type Fresnel lens, consequently it is difficult to obtain diffusion characteristic as designed when light which has been deflected is diffused by a microlens array. SOLUTION: The light enlarging deflection element 15 refracts incident projector light 9 on an annular concave lens surface 13 set as an incident surface component of an annular lens arranged like a concentric circle, and then receives it on the almost whole (for example, 90 to 100%) of the width (width in a radial direction of the concentric circle) of an annular convex lens surface 14 set as a total reflection surface component of the annular lens, and totally reflects it so as to deflect and emit to the normal direction of the screen. COPYRIGHT: (C)2009,JPO&INPIT
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