| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical element for which a Fresnel structure is used, and in which pasting (joining) together is easy and a warp is suppressed.SOLUTION: An optical element 10a comprises: a first optical element in which a concave lens 10a1 of a Fresnel structure is formed on one principal surface, the other principal surface facing the principal surface having a planar shape; and a second optical element in which a convex lens 10a2 of a Fresnel structure whose refractive index and focal distance almost equal those of the concave lens 10a1 in terms of absolute value is formed on one principal surface, the other principal surface facing the principal surface having a planar shape. The first optical element and the second optical element are joined together by a transparent adhesive member while the first plane of the first optical element having a planar shape and the second plane of the second optical element having a planar shape face each other.SELECTED DRAWING: Figure 7 |
