| 摘要 |
PURPOSE:To eliminate the entry of optical noise to focusing detecting luminous flux by providing the sub-mirror which is turnably supported to a reflecting mirror for leading the incident luminous flux from photographing optical system into finder optical system. CONSTITUTION:A reflecting mirror 10 is constituted by the two portions of the main mirror portion 11 on the outer side and the sub-mirror portion 12 of the inner side and the sub-mirror portion 12 is turnably supported at the base part of its mirror frame to the mirror frame of the main mirror portion by a shaft 13. A focusing detecting element 15 is provided before the focusing screen 14 of the finder optical system, to the former of which part of the incident light from the sub- mirror portion 12 is led. The incident light from a photographing optical system 26 is mostly led to the finder optical system by the main mirror portion 11 and part of the incident light is sent for focusing from the sub-mirror portion 12, but when the focusing ends, a lever 16 is returned and the entire quantity of the incident light is led to the finder optical system. |
