Electrophotography have been widely applied to the office copier, facsimile, printer and the other imaging field. The new high sensitive photoconductor e. g. doubled photosensitive plate having carrier generation and transport layer, dye aggregate, a-Si, CdS crystal photoconductor, are developed for the electrophotographic plate by using the organic or inorganic materials. Retention type copier, magnetographic copy-printer and laser diode printer are developed into products with the some new function added to the ordinary office copier and printer. In unconventional electrophotography, photoinjection type and photoelectrolytic imaging processes have been studied for the reproduction of continuous tone image without corona charging. As the applications of electrophotography, we could make the printing plate and the relief image instantly by EPS, pyrofax system and the deformation of the plastic film respectively.
The magnetic rolls for magnetic brush development in electrophotographic duplicator are reviewed. After introducing the principle of copy process, application of magnet rolls to double component developer system and monocomponent magnetic toner system are described. Effects of magnetic field to magnetic developer brush and transportational properties of magnet rolls are also described. Good uniformities of magnetic field are especially need for monocomponent magnetic toner system. It is concluded that the small diameter magnetic roll of single cylindrical structure and single magnetization is one of the most optimum system for developing in the point of save materials and save energy. The magnetic brush system, which has suitable magnetic patern for developer and developing unit, is the most important part of the high reliable copy machines or printers.
Dry type development in electrophotography is based on selective deposition of charged toner particles on a latent electrostatic image. The purpose of this paper is to report on the mechanism of development utilizing the magnetic characteristics of a magnetic material, based on our experimental data. The results of our experiments show that the development mechanism can be explained by an equivalent circuit model, and, further, in development utilizing a one-component-type developer, the quantity of charges of toner deposited on latent electrostatic images is proportional to the magnetic attraction of the toner to a magnetic development roller.