| 摘要 |
In an electrophotographic imaging system, a toner density control method and apparatus that uses software modeling to instantaneously compensate for image density variations due to fluctuations in toner concentration. A time-delay model of developer housing dynamics is maintained in machine software of a controller that approximates delay between toner concentration sensing and image development, delay caused by toner-carrier mixing, and/or delay caused by transport of toner-carrier from the development housing to the developer roll. The approximations can be adjusted according to actual measurements over the last several minutes of operation. The controller compares predicted toner concentration sensor signals with averaged actual toner concentration sensor signals to detect long-term and/or short-term drift. Based on the approximations and detected drift, the controller computes and transmits a feed forward correction signal to adjust electrostatic setpoints of an electrostatic controller on a print-by-print basis in order to compensate for fluctuations in toner.
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