| 摘要 |
PURPOSE:To drive a lens and a shutter by a single actuator by enabling the engagement contact part of a multipolar rotor to move under the guidance of the engagement contact part of a driving member while rotating when a stepping motor is driven at the time of photography according to distance measurement information. CONSTITUTION:When the coils 5 and 6 of the stepping motor 3 are fed with electricity from a driving circuit at the time of photography according to the distance measurement information, magnetic poles 7a, 8a, 9a, and 10a are excited and a rotor 11 is rotated in one direction, e.g. counterclockwise by a set number of steps according to the distance measurement information. Then when the motor 3 is reversed according to light measurement information, the rotor 11 rotates in the other direction, i.e., clockwise, but the rotor 11 and a driving ring 17 rotate associatively and neither the rotor 11 nor a lens barrel 14 move back, so that a lens is held at a specific extension position. Then the rotor 11 is further rotated counterclockwise and when the tail end part of each stage cam 11 moves beyond a lock column 17d, the lens is returned to its initial position. Then the stepping motor 3 also stops and photographic operation for one frame is completed. |
