| 摘要 |
PROBLEM TO BE SOLVED: To provide a photographing lens capable of improving a rising characteristic in an AF control with respect to a camera having a twin motor system lens with an ultrasonic motor in the lens. SOLUTION: The photographing lens includes a focus mechanism 3 and an AF mechanism 4 for performing the AF control by driving the focus mechanism 3 in the photographing lens 2, wherein the AF mechanism 4 includes a motor 43 in lens (ultrasonic motor) for driving the focus mechanism 3 and is configured so as to transmit rotation force of a motor 112 in body (DC motor) of a camera body 1 to drive the focus mechanism 3. The AF mechanism 4 includes a one-direction clutch 44 which intercepts the transmission of rotation force from the ultrasonic motor 43 toward the DC motor 112. When performing the AF control, the DC motor 112 is rotated and driven at first, the ultrasonic motor 43 is forcibly rotated by the rotation force, thereby, the conglutination between a stator and a rotor of the ultrasonic motor 43 is dissolved and the rising characteristic of the rotation of the ultrasonic motor 43 is improved. COPYRIGHT: (C)2008,JPO&INPIT
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