| 摘要 |
PROBLEM TO BE SOLVED: To prevent the degradation of the image quality of an observation image even if the flashes generated at the time of production exist in an optical element by opening the flashes generated at the time of molding of an incident surface on which the light from a display means is made incident and the surface adjacent thereto to an outer side with respect to the center of the incident surface. SOLUTION: A prism 4 consists of a first surface 4a which is a transmission surface, a second surface 4b which is a total reflection surface and a transmissible surface and a third surface 4c which is a concave reflection surface subjected to mirror coating and is a plastic element which is integrally molded by a medium having a refractive index greater than 1. The surface of a mirror finished surface barrel is subjected to mirror finishing in order to mold the respective surfaces of the prism 4. When the prism 4 is molded by molding metal molds, the flash generated at the boundary parts of the respective mirror finished surface barrels are generated in the form of opening to the outer side with respect to the center of the first surface 4a which is the incident surface. Then, the unnecessary light reflected by the flashes is no more made incident on the first surface 4a and the generation of flares and ghost light is prevented. The deterioration of the image quality of the observation image is thus averted.
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