| 摘要 |
PURPOSE:To reduce the fear of a trouble and to miniaturize the subject lens barrel by constituting a lens driving mechanism so that a rotating speed of a motor is decelerated mechanically at the time of approaching both ends f a movable range. CONSTITUTION:A rotor holding ring 12 rotates together with a rotor 6 by an oscillatory wave motor M, and a roller 13 pressed against the rotor holding ring 12 rotates centering around an optical axis Z together with a ring 14, while rolling along an orthogonal surface 1c-1 of an outer cylinder 1. When a focus of a photographing optical system approaches a telephoto end of a wide end, the roller 13 moves from the orthogonal surface 1c-1 of a lens barrel to 1c-2, and the ring 14 and constituting parts of the oscillatory wave motor M are brought to axial direction movement in the right direction, therefore, a rotating speed of the rotor 6 decreases. When a lens L reaches the telephoto end or the wide end, a linear cylinder 3 hits against a stopper and stopped forcibly. In such a way, since a deceleration switch and a deceleration program become unnecessary, a fault scarecely occurs and the lens barrel can be miniatur ized. |
