Optical device of copying machine

Abstract

Abstract PURPOSE: To copy also the end parts of original image, when copying at magnification other than identical magnification, by causing the size of the original image to coincide with the size of the part excluding the non-image forming part of copying part, and causing the original reference end to coincide with the boundary of the non-image forming part and image forming part. CONSTITUTION: A lens L is moved to positions of H, I, so that the original reference end of an original image 4 may be nearly the boundary of the non-image forming part and image forming part, regardless of the copying magnification. When the copying magnification is changed from n 1 to n 2 , the lens L is moved to the photosensitive drum side by (a' 2 -a 1 ), i.e., (1/n 2 -1/n 1 ), in the direction of optical axis. In order to image the image of original reference end 4a in the boundary of the part forming the image avoiding the non-image forming part and the part not forming the image, the lens L is moved by Δl' 12 , i.e., (n 1 -n 2 )l 1 /(1+n 2 ) in the direction vertical to the optical axis. (Where, l 1 is the distance between the optical aixs position of the original and reference end part when the magnification is n 1 .) COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Koichi Miyamoto

Bibliographic Details