| 摘要 |
PURPOSE:To execute a copying to forms of various sizes by providing as an image forming lens, a variable power lens which can execute the variable power by moving in an optical axis direction for connecting a plate write surface and the surface of a photosensitive body, varying a focal distance, and keeping a distance between an object surface and an image surface constant. CONSTITUTION:Picture information of a sheet 1 illuminated by an illuminating device is made to form an image on a photosensitive body 10 through reflecting mirrors 7, 8 and an image forming lens 9, and copied by an electrophotographic device 11. In such process, the image forming lens 9 moves in the optical axis direction for connecting the plate write surface and the surface of the photosensitive body and is constituted of a variable power lens which executes a variable power by keeping a distance between the object surface and the image surface constant by the variation of a focal distance, therefore, a plate write area A can be copied by other magnification than that of a basic mode. That is to say, when the variable power lens 9 is in a position (a), the section l1 of the plate write surface 1 is enlarged and copied to the section d1 of the surface of the photosensitive surface. In the same way, when the variable power lens 9 is in a position (b), the section l2 of the plate write surface 1 is copied by the basic mode to the section d1 of the surface of the photosensitive body, and also, when the variable power lens is in a position (c), the section l2 is reduced and copied to a section d2. |
