| 摘要 |
PURPOSE:To secure control over an automatic flash mechanism by shaping a linkage part through which the 3rd blade provided having no direct relation during exposure links with a shutter driving mechanism so that it operates large only at small aperture, and detecting a slit or reflecting part provided to the 3rd blade by a projectig element and a photodetecting element. CONSTITUTION:A blade driving pin 6 begins to rotate counterclockwise around a shaft 3, shutter blades 1 and 2 start operating in opening directions, and the 3rd blade 5 also rotates clockwise at the same time. The 3rd blade 5 abuts on the blade driving pin 6 and the cam part 5b of its cam hole 5a in the beginning, so it operates similarly to the shutter blade 2, but when the shutter blades 1 and 2 begin to open, the blade driving pin 6 engages the cam part 5c and the operation angle of the 3rd blade 5 becomes larger than that of the shutter blade 2. Consequently, when the end part 5d of the 3rd blade 5 is set to, for example, F16 and the slit part 5e is set to F11, the operation angle of the 3rd blade 5d between the both is increased and the slit width between 5d and 5e is made larger than before. |
