| 摘要 |
PROBLEM TO BE SOLVED: To make it possible for a photographer to optionally set the moving range of a focusing lens group and also to perform a useful focusing operation at the time of moving, as for a lens barrel. SOLUTION: The focusing lens group L1 is moved by a cam cylinder 14 which is rotated by an actuator constituted of a rotor 20, etc., based on the focus signal from the camera, and a brush 34 for reading the signal of a potentiometer 33 relatively moving with the cam cylinder 14 is installed on the fixed barrel 11 which is engaged with the cam cylinder 14, on the other hand, 1st and 2nd optional points in the moving range of the focusing lens group L1 are set by a setting switch, and also, the points are stored by a memory circuit, and the lens barrel is provided with a calculation circuit for calculating the moving distance and moving direction of the focusing lens group between the 1st and 2nd optional points and a selection switch for selecting the moving range, and then, the moving distance of the focusing lens group between the 1st and 2nd points is calculated based on the output of the potentiometer 33, then, the movable range is controlled. |
