Adjustment manner of try level image and state adjusting device null of try level

摘要

PURPOSE: To make an image part in a desirable electrified state by exposing a tri-level image on a photoreceptor to light and corona discharge before transfer. CONSTITUTION: The successive part of a charge holding body in the form of a photoconductive belt 10 passes an electrifying part A, an exposure part B, and a developing part C so as to form the tri-level image on the photoreceptor. Since the composite image developed on the photoreceptor consists of positive toner and negative toner, the state of the toner is adjusted so that the image may be efficiently transferred to a base plate in a transfer part D by using negative corona discharge by providing a lamp/reflector assembly 48 and a pretransfer positive corona discharge body 56. By exposing and discharging the photoreceptor carrying a composite developed latent image before starting the pretransfer electrification, more charge is selectively applied to a composite tri-level image part than any other image part. Furthermore, the overelectrification of the image part is prevented by irradiating the photoreceptor with a light beam simultaneously with the pretransfer electrification.