Abstract
Properties of toner charge and toner mass amount on a developing roller for non-magnetic mono-component developing system have been investigated with a compact draw-off type instrument for measuring toner charge and toner mass amount. Pushing pressure of the blade to the developing roller, surface roughness of the roller, and external additives on toner surface affect toner mass amount of the toner layer on the roller as well as toner charge of the toner layer. These influences were examined in this study. As a result, the following were clarified. (1)In the case of changing the pushing pressure of the blade and the surface roughness of the roller, the toner charge on the developing roller is increased when the toner mass amount is decreased. Therefore, the area charge, which is defined by a product of the toner charge and the toner mass amount, was almost constant. (2)When the content of the small diameter silica used as the external additive in this study is increased, both of the toner charge and the toner mass amount are increased. Therefore, the amount of the area charge is also increased. (3)The area charge is very important to determine charging properties of toner particles in the mono-component developing system.
