JPS54133138A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To realize erasing of charging in a particular region, by opening the shutter when not exposing the original on the photoreceptor, and radiating the outside region of the image forming region of the photoreceptor at the time of blank exposure and when projecting optical image for electrostatic latent image forming. CONSTITUTION:In the image exposure process of an original platen 5, since a shutter 16 is disposed in the solid line position as shown in the drawing, the light from a lamp 6 passing through a slit 7b in a reflector shade 7 is shielded for the photoreceptor la, so that only the image from the original face may be exposed. At the time of blank exposure, namely, when the image formation scanning means returns, the shutter 16 retreats to the position shown by dotted-line position, and the light passing through slits 3b, 7b radiates the entire width of the photoreceptor at the original image exposure part, so that the potential at the photoreceptor 1a may be the same as when the original having the entirely white surface is projected. As a result, the electric charge disappears, and the developer does not deposit on both bright and dark parts. Therefore, it is possible to prevent increase of the load of cleaning device, contamination of separation pawl with developer, and similar inconveniences.