| 摘要 |
Both end parts of a feed screw device are movably supported through cushioning members, and an inertia force of the screw after a movable member moved by the screw has collided against a stopper is absorbed by a movement in an axial direction, so that an impact at a drive end can be softened. When the guide part comes into contact with the stopper and a projection lens barrel is positioned at an upper end of a moving stroke, an upward movement of the barrel is stopped, but a motor is in a rotating state. A driving power of the motor is continuously transmitted to the screw, but since an upward movement of a nut member is restricted, a downward movement force is given from the motor to the screw. Then, the screw moves downward against an urging force of a spring.
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