Electrophotographic image producer esp. for double-sided printing or copying - uses pressure roller elastically mounted on upstream side of electrostatic transfer unit facing rotary drum

摘要

A photosensitive drum (2) of e.g. amorphous Si rotates (P) in one direction and is uniformly charged with predetermined polarity by a corotron (4). A latent electrostatic image is formed by a printhead (6) having e.g. a row of LED's parallel to the axis. Sheets of paper (12) are fed between the drum and a pressure roller (18). One side is brought into contact with the drum by a transfer unit (20) for application of an AC corona discharge with polarity opposite to that of the toner image. The sheet is reversed (34) for printing on the other side. USE/ADVANTAGE - In electrophotographic printer or copier with LED printhead, quality of prod. is enhanced.