| 摘要 |
A reliable barrier device for a camera, which is able to smoothly open and close blade members while suppressing a drive load applied when the blade members are opened and closed. Closing springs for primary and secondary blades are each interposed between corresponding ones of spring hooks on a barrier drive ring and on primary and secondary blade members. When the drive ring is rotated in a barrier opening direction, the distance between the spring hook on the ring and the spring hook for primary blade decreases and the urging force of the closing spring for primary blade decreases, which reduces a rotational torque produced by the closing springs for primary and secondary blades at barrier open state, making it possible to decrease a rotational torque produced by opening springs and acting on the drive ring at barrier open state. |
