| 摘要 |
PROBLEM TO BE SOLVED: To provide a large-sized projection lens having high shape accuracy in spite of the light-weight and inexpensive one, assembled especially in a projection device projecting an image not from a perpendicular direction to a screen but from an oblique direction, especially, from an obliquely lower side, and projecting the high definition image free from distortion and deformation. SOLUTION: This projection lens is provided with a reflection layer on the surface of resin base material formed to be a specified curved surface, and the mean value of the phase difference of in-plane double refraction per unit thickness with respect to incident light from the perpendicular direction to the optical functional surface of the resin base material at the curved surface part of the lens is set to <=30 nm/mm in an area being at least 60% of the area of the optical functional surface, and a metallic reflection film and a transparent protective coat are successively formed at the curved surface part.
|
