Patent ID: 8768189
Filing Date: 2014-07-01
Classification: G03G

Abstract:
1. A method of charging a photoreceptor to a desired voltage level comprising: providing a first corona charging unit having a first corona electrode, a first shell electrode, and a first high voltage power supply; connecting the first shell electrode through a resistor to ground; connecting the first high voltage power supply to the first corona electrode; providing a second corona charging unit having a second corona electrode, a first grid electrode, and a second shell electrode; connecting the grid electrode to the second shell electrode; sensing a first corona current from the first high voltage power supply to the first corona electrode; sensing a return current from the first shell electrode to ground; adjusting a voltage on the first high voltage power supply to maintain a constant difference between the first corona current and the return current; wherein the first corona charging unit charges the photoreceptor to at least 63% of the desired voltage; and wherein the second corona charging unit charges the photoreceptor to within 10% of the desired voltage.