Photoelectrostatic copier with reusable photoconductive belt - avoids use of clumsy costly scanning lenses and has bias potential applicator

摘要

Photoelectrostatic copier for producing copies on ordinary non-photoconductive paper comprises a reusable flexible photoconductive belt (24) which is moved over a row of guide rollers (30, 32, 34). In a rectilinear zone of one run of the belt is an exposure device (92) mounted behind a charger device, and behind the rectilinear zone is a powder developer with means for producing a bias potential for reducing the quantity of light required and re-collecting unused developer particles. Coacting with one of the guide rollers is a transfer roller (124) which operates at the bias potential, with means (140) for adjusting the pressure applied by the transfer roller to the copy sheets.