1987 Volume 26 Issue 2 Pages 107-114
A model is proposed which describes the toner charging in a mono-component non-magnetic developement system. No magnetic material is necessary for this system. By means of an elastic metal blade which is pressed against the roughened surface of the developing roller, a thin layer of the non-magnetic toner is formed on the roller. Toner particles are charged triboelectrically by friction with the blade and the roller. The latent image is developed with the non-contact developing technique.
The following conclusions are derived from the analysis of the relationship between the potential distribution in the toner layer and the current flowing into the blade: (1) 30% of the toner charge is generated by friction with the blade, (2) Toner particles which have a saturated charge get once a surplus charge Δq by contact with the blade, (3) The surplus charge Δq flows through the toner layer and is discharged to the roller, (4) The metal blade controls the toner charging and the toner charge is maintained at a constant value. The numerical calculations agree well with the experimental results.
An application to a two-color laser beam printer is studied. The undesirable mixing of the defferent color toners does not occur on the photoconductive drum and in the developing apparatus, because the toner layer does not contact with the drum surface.
