Electrophotography system.

摘要

An electrophotography system for use in laser printers, printing machines and copying machines. The system includes a rotatable drum having a photosensitive member which can take a first absorption spectrum state and a second absorption spectrum state, the variation from the first absorption spectrum state to the second absorption spectrum state being made by illuminating it with light whose intensity is above a predetermined threshold and whose wavelength is in a first predetermined wavelength region. Also included is an optical system including a light-emitting device for illumination of the photosensitive member so as to form thereon an electrostatic latent image, the optical system being arranged to directly illuminate the photosensitive member with light from the light-emitting device and further to illuminate it with reflected light from an original picture. The light-emitting device is arranged to emit light whose wavelength is in the first predetermined wavelength region and further light whose wavelength is in a second predetermined wavelength region. A control unit performs one selected from a laser-printing mode, a printing mode and a copying mode so as to form the corresponding electrostatic latent image on the photosensitive member by lights which are different in intensity and wavelength from each other.