Patent ID: 7403334

Claim:
An optical member having planes of incidence and emergence, comprising: an optical element that changes an optical path of incident light, the optical element being formed on at least one of the planes of incidence and emergence, wherein a predetermined part of the optical member, selected from the planes of incidence and emergence, has a plurality of minute concavities by which reflection of light incident on the predetermined part is prevented, and wherein the optical member is formed by casting a molding resin upon a surface, of a mold and by curing the molding resin, the surface of the mold having formed thereon a plurality of minute protrusions of deposited particles in a shape that is a reverse of a shape of the plurality of minute concavities, wherein the concavities have a mean depth of 0.05 μm or more and 0.5 μm or less, and a mean distance between neighboring two of the concavities is not more than 0.5 μm, the concavities have a mean radius in a direction of plane 0.5 to 2 times the mean depth of the concavities, the mean depth of the concavities is 0.2 to 2 times the mean distance between neighboring two of the concavities, and wherein, of the optical member, a laminar portion including with the concavities has a percentage of void of 20 to 50%.