Patent ID: 8948635
Filing Date: 2015-02-03
Classification: G03G

Abstract:
1. A system for charging a photoreceptor to a desired voltage level comprising: a first corona charging unit having a first corona electrode, a first shell electrode, and a first high voltage power supply; wherein the first shell electrode is connected through a resistor to a first ammeter; wherein the first high voltage power supply is connected to the first corona electrode; a second corona charging unit having a second corona electrode, a first grid electrode, and a second shell electrode; wherein the grid electrode is connected to the second shell electrode; a second ammeter for sensing a first corona current from the first high voltage power supply to the first corona electrode; wherein the first ammeter senses a return current from the first shell electrode to ground; a controller for 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 plus or minus 10% of the desired voltage.