| 摘要 |
PURPOSE:To obtain an always adequate image by providing a measuring means which measures optically the characteristics of an original, a moving means which moves relatively the measuring means and the original and a control means which controls the moving means so as to move the same for the purpose of the measuring stage prior to the exposing stage. CONSTITUTION:The image of an original is fed to a reflecting mirror 12 and is projected to a lens 13 and a reflecting mirror 14 by which the image is formed on a photosensitive drum 15. A part of the quantity of the light reflected by a half mirror 16 is conducted to a reflecting mirror 17 to be fed in the direction perpendicular to the moving direction of an original base and the light obtd. via the mirror 17 is condensed a photodetector 18 having the photosensitive wavelength characteristic coinciding with the emission spectrum of a light source for exposing the original and the photosensitive wavelength characteristic of the photosensitive drum. The video signal of the original converted to an electrical signal by the photodetector 18 decides whether the original has many fine characters and lines or has much medium constract in a decision circuit. The copying operation of the original placed on an original plate 10 is accomplished according to the detection of such original content. |
