Abstract: An image device includes a movable member, a guide shaft, and a shaft bearing. The movable member moves back and forth inside the device along a guide shaft when reading or recording image information. The guide shaft includes an arc portion in at least part of a cross-section. The shaft bearing is penetrated by the guide shaft at two locations in the movement direction that differ from the center of gravity in the movable member. The shaft bearing includes two inclined faces contacted by the arc portion of the guide shaft in the cross-section. The respective two inclined faces of the shaft bearing are at an angle ?f (rad) and an angle ?r (rad) with the perpendicular direction. The angle ?f (rad) and the angle ?r (rad) satisfy the following inequality: cos {?/2?(?f+?r)}>0.

Abstract: An image device includes a movable member, a guide shaft, and a shaft bearing. The movable member moves back and forth inside the device along a guide shaft when reading or recording image information. The guide shaft includes an arc portion in at least part of a cross-section. The shaft bearing is penetrated by the guide shaft at two locations in the movement direction that differ from the center of gravity in the movable member. The shaft bearing includes two inclined faces contacted by the arc portion of the guide shaft in the cross-section. The respective two inclined faces of the shaft bearing are at an angle ?f (rad) and an angle ?r (rad) with the perpendicular direction. The angle ?f (rad) and the angle ?r (rad) satisfy the following inequality: cos {?/2?(?f+?r)}>0.