Abstract
A contact-type monocomponent non-magnetic development using a conductive and elastic development roller is effective for the improvement of image quality of photoprinters because the development electrode is held extremely close to the latent image. Recently, development systems which employ semi-conductive or dielectric rollers are also studied. The authors propose a unified theory which describes the physics of these three kinds of contact development systems. Development currents are taken into consideration in the analyses, and equations which show the relation between the roller resistance and the development characteristics are derived. The results of analyses and experiments show that a conductive roller, having a low friction-coefficient conductive surface layer and a resistivity of less than 1×104 Ωm2, to which a development bias voltage is applied through a protective resistor of l to 10 MΩ, is most advantageous.
