| 摘要 |
PURPOSE:To detect surely a mark and to prevent mis-retrieval regardless of the recording position of the mark, by lighting the mark of a picture part through a prism and interlocking the prism and a mark detector. CONSTITUTION:An optical member consisting of a wedge-shaped prism 25 is arranged between the condensor lens 15 and a glass plate 16. The prism 25 has a plane 251 in parallel with the film plane. A light (a) through the condensor lens 15 is made incident from the lower end face of the prism 25 and irradiated vertically from the upper end face 251. A mark detector 21 and the optical member 25 are fixed to a moving member 27. A screw rod 28 is fitted freely turnably to one end of the moving member 27. In turning an operating knob 30, the screw rod 28 is turned, the moving member 27 is moved and the mark detector 21 and the optical member 25 are moved interlockingly. |
