| 摘要 |
PROBLEM TO BE SOLVED: To correct the deviation of an image-formation surface and to maintain high optical performance by controlling a lens driving means based on control information and correcting the fluctuation of the position of the image- formation surface of an optical system associated with temperature change. SOLUTION: Driving circuits 15 and 17 drive STEP motors 5 and 6 functioning as a lens driving means. A temperature sensing resistance 12 such as a thermistor functioning as a temperature detection means outputs an output signal corresponding to temperature by a detection circuit 24 to a control circuit (control means) 13 such as a microcomputer. In such a case, the temperature change of the optical system is detected by the temperature detection means 12 through a heat transfer member 26 attached to a lens barrel 2. By utilizing the output signal from the temperature detection means 12, the control means 13 controls the position of a RR (4th lens group) 104 on an optical axis so as to correct the fluctuation of the image-formation surface. Even just after a power source is turned on, the temperature information of the optical system by the temperature detection means 12 is rapidly and accurately detected and the moving locus of a moving lens group is appropriately set at each time. |
