Patent ID: 7551352
Filing Date: 2009-06-23
Classification: G03B,H04N

Abstract:
1. An image display apparatus, comprising: an image generating source; a picture enlarging portion for enlarging a picture from said image generating source; a screen on which the enlarged picture is projected from a rear side thereof; and a projection optical portion for projecting the enlarged picture of said image generating source from said picture enlarging portion on said screen, through oblique projection thereof, wherein said screen includes at least a Fresnel lens sheet forming a Fresnel lens thereon, a plurality of prism surfaces of said Fresnel lens each having a Fresnel angle depending upon an incident angle of a light beam from the oblique projection on said each of prism surface, wherein said Fresnel angle is larger in an upper portion of said Fresnel lens sheet than in a lower portion thereof, upon a cross-section surface passing through a central axis of said Fresnel lens, and wherein said Fresnel lens is formed concentrically around a same point of a center, and said central point is located in an outside of said screen.