| 摘要 |
PURPOSE:To perform resetting operation of aperture blades smoothly by disposing a permanent magnet to one of movement limiting parts for aperture diameter setting members and a magnetic material to the other, respectively, thereby effecting a magnetic coupling function. CONSTITUTION:A permanent magnet 16 is provided to at least one of movement limiting parts for an aperture blade operating ring 11 and an aperture diameter setting ring 13 limiting the movement extent of this ring 11 driven by motors 4, 5. A magnetic material 17 is provided to the other, so that a magnetic coupling function is effected by this permanent magnet 16 and the magnetic material 17. |
