Patent ID: 6822770
Filing Date: 2004-11-23
Classification: G02B

Abstract:
An observation optical system comprising:an observation image forming member which forms an observation image to be observed by an observer; and an eyepiece optical member which introduces the observation image formed by said observation image forming member into an exit pupil formed at a position of an eye of the observer, wherein said eyepiece optical member comprises, at least, a first prism and a second prism, wherein said first prism comprises, at least, a first entrance surface through which rays from the observation image enter said first prism, a reflecting surface which reflects the rays inside said first prism, and a first exit surface through which the rays exit out of said first prism, said first entrance surface, said reflecting surface, and said first exit surface being arranged with a first prism medium between, wherein said second prism comprises, at least, a second entrance surface through which the rays emergent from said first prism enter said second prism and a second exit surface through which the rays exit out of said second prism, said second entrance surface and said second exit surface being arranged with a second prism medium between, wherein said first prism and said second prism are configured to be joined to one another via a hologram element interposed between said first exit surface and said second entrance surface, wherein said reflecting surface of said first prism is shaped as a concave curved surface to give a positive power for rays reflected therefrom, wherein said first entrance surface of said first prism is shaped as a curved surface to give a power for rays transmitted therethrough, and wherein said second exit surface of said second prism is shaped as a curved surface to give a power for rays transmitted therethrough.