| 摘要 |
PURPOSE:To realize the best focusing state without tension the eye of an observer by setting the maximum necessary time for the lens movement of the telescope with an automatic focusing function shorter than the focusing time of the human eye. CONSTITUTION:A focusing detection module 19 processes an electric signal, obtained according to an image of an observed body imaged on a CCD line sensor, by a system controller to operate the movement quantity of the lens, and the result is sent as an electric signal to a motor 22 to move forth and back objectives 13 and 14 through a speed reducing gear part 23 coupled with the rotary shaft, thereby focusing the telescope on the observed body. The adjusting speed of the human eye is about 0.6-1 second, so the movement speed of the lenses 13 and 14 between a short-distance point and infinity is set to <0.6 second by setting the motor 22 and gear part 23. Consequently, the telescope already enters the focusing state before the focus adjusting operation of the eye (i.e., tension of eye) and the best focusing state is obtained without tensing the eye of the observer extremely. Consequently, the eye is not fatigued during the observation. |
