| 摘要 |
PURPOSE:To achieve high precision control by providing a zoom driving system changing the magnification of zoom lenses with marks in response to the magnifications of the zoom lenses and detecting the marks, thereby detecting the magnifications of the zoom lenses. CONSTITUTION:One of zoom gears 94 provided on the zoom lenses 68, 70 and 72 is equipped with plural magnification reference holes 108 in the circumferential direction. A scanner 84 is provided with a magnification reference position sensor 110 composed of an optical sensor, etc., in response to the zoom gears 94. The magnification reference holes 108 are made in positions indicating the integer magnifications of the lenses 68, 70 and 72. When the sensor 110 detects the holes 108, the integer magnification positions of the lenses 68, 70 and 72 can be detected. Since the actual magnification of the zoom lens can be detected by the marks provided on the zoom driving system in such a way, the accumulation of errors regarding magnification can be eliminated to control the magnifications of the zoom lenses at high precision. |
