| 摘要 |
PROBLEM TO BE SOLVED: To realize high-speed autofocusing with high positional accuracy. SOLUTION: Both end parts of an image pickup device 11 are fixed to a metallic belt 12 laid over two sets of pulleys 13 and 14. A pulse number corresponding to an image pickup distance detected by a height sensor 24 is calculated by a controlling part 25 after the image pickup device 11 is moved to an original position 11c by firstly reversely rotating a pulse motor 15. Next, the motor 15 is rotated in a normal direction only for the pulse number, and the image pickup device 11 is linearly moved from the original position 11a in the direction of an arrow A, so that it is stopped at a focal position. Thus, autofocusing operation by feed-forward control is realized and high-speed control is executed and the accuracy of the focal position is improved. |
