| 摘要 |
PURPOSE:To perform correction automatically for flash photography, by deciding on an aperture diameter which corresponds to an object distance through a correction cam by switching performed in accordance with the indication of an aperture scale ring. CONSTITUTION:When an aperture scale ring 1 is rotated from an area A for normal photography to an area B for flash photography, an aperture deciding cam 12 is brought into contact with a stop member 22 by a spring 18. A correction cam is rotated, corresponding to respective guide numbers on an aperture scale, by a coupling lever 14 and a pin 16 on the correction cam 13. When a lens barrel member 5 is moved outward through the rotation of a focusing ring 2, the pin 16 on the correction cam 13 slides in contact with the cam surface 17 of the coupling lever 14 to move in the direction of an optical axis, so the correction cam 14 is rotated in accordance with the outward movement of the correction cam 13 to decide on an aperture, which corresponds to an object distance, by a cam surface 13a through a pin 19 on a bell crank 10. Thus, correction is performed automatically by the simple constitution. |
