| 摘要 |
PROBLEM TO BE SOLVED: To prevent occurrence of displacement of a lens before or after the shut off of a power source or when switching between invalid and valid states.SOLUTION: If the difference between the position of a magnification variable ring 117, before the power source is shut off, or when an operation by the operating member is switched to an invalid state from a valid state and the position of the magnification variable ring 117 detected by a potentiometer 118, after the power source is turned on, or when the operation by the operating member is switched from an invalid state to a valid state is below a threshold; and the magnification variable lens 102 is moved with the position of the magnification variable lens 102, before the power source is shut off, or when the operation by the operating member is switched from the valid state to the invalid state as an initial position. When the difference is larger than the threshold, the magnification variable lens is moved with the position of the magnification variable lens corresponding to the position of the variable ring 117 detected by the potentiometer 118 as initial position. |
