A kinetic model was introduced on the assumption that the charging process is a reversible transfer of charge, and the kinetics of the tribocharging of model two-component developers was studied using a quaternary ammonium-type CCA. A linear relationship between the inverse of saturated tribocharge (q_e)and toner-to-carrier mass ratio (m_t/m_c) automatically followed from the kinetic model. The reciprocal of the intercept on the 1/q_e axis was, for the first time, found to be the charge which could be transferred to the carrier when no reversion of the transfer of charge occurred from the carrier to the toner, named the limiting charge. The ratio of the normal and the reverse tribocharging rate constants (k₁/k_-1=K) was shown to be constant and intrinsic for the combination of materials. It was showed that the inverse dependence of q_e and m_t/m_c derived from the kinetic model was formally consistent with that from the surface-state model. The charging-rate constant (k_obs) was for the first time found to be expressed in the Arrhenius equation, and the apparent activation energies (E_a) obtained were similar to the van der Waals binding energy. The kinetic study proved that q_e was independent of k_obs and limiting charge was independent of the number of the charge-generation site and was dependent on the solid-state properties of CCA. Their small activation energy led to the conclusion that the counter-ion transfer is most favorable in quaternary-ammonium-type CCA.

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Fundamental toner properties and development characteristics in nonmagnetic monocomponent development were studied. An electrophotographic developing unit consisting of a developing roller, a toner supply roller and a regulating blade connected with bias voltage supplies were used. Influence of bias voltages applied to the toner supply roller and the regulating blade on the properties of the toner layer and the development characteristics were examined. The development characteristics were characterized by the separation of the toner layer associated with applying an electric field between a metal plate and the developing roller. Changes in the bias voltage to the toner supply roller and to the regulating blade caused changes in the toner supply mass and the blade pressure on the developing roller, respectively. The bias voltages to the regulating blade influenced charge injection to the toner layer and the charge distribution within the toner layer, resulting in changes in the properties of the toner layer and the development characteristics. The toner charge at the surface of the toner layer was changed more largely than that at the bottom of the toner layer by the bias voltage to the regulating blade. The development characteristics approached a theoretical one as the bias voltage to the regulating blade increased.

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Calibration, based on Color Management System concept, may be defined as a means towards a device independent process; which in another term, is a method of standardization of RGB coordinates to be as CIE standards. In Electronic Prepress System (EPS), it is a must that a color scanner should be calibrated to ensure the color information of an original. Throughout experimental, it is found that the process of gray balance and tone reproduction adjustment of scanner responses is necessary before transformation (RGB → CIE L*a*b*). A linear matrix coefficients is possible, while other multiple regression is also applicable, as color difference values (AE) are less than 6.0. In addition, comparison is made with another technique using color space conversion RGB rarr; CIE XYZ through 1-D look-up table of tone adjustment. Similarly, the result is acceptable with linear matrix transformation. The special programs were developed for this purpose which enable to ease the software/hardware design and quick process in EPS.

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