| 摘要 |
PROBLEM TO BE SOLVED: To provide a superimposing device for a finder screen, the device being designed so that the weight of a penta-roof is reduced and assembly cost is also reduced. SOLUTION: A penta-roof mirror is used for a finder optical system of a single lens reflex camera. Light entering from a photographic lens is reflected by a quick return mirror 10 and imaged onto a focusing plate 11. A subject image on the focusing plate 11 reflected by a roof mirror 13, which is disposed on the penta-roof 12, and a third reflecting face 14, which is a half mirror, is observed through an eyepiece optical system 16 of a finder 15. A mirror composing a third reflecting face is formed integrally with a triangular prism, so as to obtain a prism 18 integrated with the third reflecting face. Light emitted from a light source section 20 is reflected by a light projecting mirror 21 and also made incident on the triangular prism 17 through a light projecting lens 22. Light reflected by a reflecting face 17R through the third reflecting face 14 is emitted into the penta-roof along the optical axis of the eye-piece optical system 16. COPYRIGHT: (C)2008,JPO&INPIT
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