| 摘要 |
<p>PURPOSE:To improve the utilization of light, by dividing the surface of a mirror for photodetection into plural blocks, and forming each block into two reflecting surfaces which send light corresponding to the center part of a picture plane and light corresponding to the part outside of the center part to a photodetecting element and thus guiding the light to the photodetecting element. CONSTITUTION:Light passed through a photographic lens is reflected by the 1st mirror 1 as a mirror for observation and guided to a viewfinder optical system. The viewfinder optical system consists of a focusing plate 4, condenser lens 5, pentagonal prism, and ocular 7. The 1st mirror 1 has a passing area in the center and light passed through this area is reflected by the 2nd mirror 2 or the 3rd mirror 3 as a mirror for photodetection, focused by a photodetection optical system 8, and then photodetected by the photodetecting element 9.</p> |
