Method and apparatus for predicting the cycle-down behavior of a photoreceptor

Abstract

Charges on a photoreceptor dissipate quickly before a latent image enters the development stage of the machine where the image is developed. The photoreceptor's charge potential before entering the developer is called the dark development potential. In order to control the photoreceptor's dark development potential, an adaptive cycle is used to predict the cycle-down effects on the photoreceptor. Charge potential measurements are obtained during the normal print runs and the actual values are used to control the subsequent charging steps. Therefore, the process adapts to the next charging cycle based on the results of the present charging cycle. The method and apparatus adaptively predict the behavior and thereby account for the cycle-down effects when charging the photoreceptor. The method recognizes that in spite of the various parameters that can effect the dark developing potential during cycle- down, the ratio of the variation of the dark developing potential with respect to the predicted steady-state potential is generally constant from one charging cycle to the next. By using a method of deviation ratios, an adaptive prediction of the dark developing potential and also minimized effects due to errors in predicting the level of steady-state of the dark developing potential are achieved.