| 摘要 |
PURPOSE:To make focus adjusting at each variable power easy and sure by adjusting the focus in mirror stop positions at the scaling-down and finely adjusting the lens stop position in the same mirror stop positions at the magnifying thereby adjusting the focus. CONSTITUTION:The positions of the 1st and 2nd mirrors 27, 28 are set to a frame by holders 27a, 28b, and the stop position of a lens 30 at the unmagnifying is determined by defining the position of a lens holder 45 with a defining device 62. Focus adjustment is accomplished by rotating an eccentric pin 84 to displace the relative angle of a lever 79 with respect to a lever 80 and defining the stop positions of the 3rd and 4th mirrors 31, 32. At the scaling-down, the focus adjustment is accomplished by rotating a stopper pin 87 and defining the stop positions of the mirrors 31, 32. At the magnifying, the stop positions of the mirrors 31, 32 are defined by the stopper pin 87 in a manner similar to that in the scaling-down but the focus adjustment is performed by adjusting the stop position of the lens 30 by moving a stopper screw 51 forward or backward. In this way, the focus may be adjusted easily and surely at each variable power. |
