| 摘要 |
PURPOSE:To vary the power to a prescribed value accurately with a simple mechanism by providing a comb tooth-shaped member having plural grooves on slide frames of a lense and mirrors which are moved for varying the power and providing a stopper which can be taken into and out from teeth of this member. CONSTITUTION:The light from a light source L is reflected on an original and passes mirrors 3 and 4, a lens 5, and a mirror 6 to focus a pattern of the original onto a photosensitive body 7. The magnification is varied by changing the length between the mirror 4 and the lens 5. U-shaped slide frame 15 and an inverted U-shaped slide frame 16 which are joined elastically by a spring 23 are moved forward or backward along a shaft 13 to determine the position of the mirror 4. A lens frame 5 is supported by a comb booth-shaped member 34 which is moved forward or backward along a shaft (omitted in the figure) parallel with the shaft 13 and has plural grooves 35, and a projection of a stopper mechanism 36 is rushed into one of grooves 35 in accordance with a desired magnification of determine the position of the lens 5. Thus, the optical path length from the original 2 to the photosensitive body 7 is extended or reduced to change the variable power easily, and the number of grooves of the comb tooth-shaped member is increased to set the variable magnification variously. |
