Patent ID: 9176416
Filing Date: 2015-11-03
Classification: G03G

Abstract:
1. A charging device comprising: a discharge electrode for establishing a discharge; a grid electrode arranged between the discharge electrode and a latent-image bearer of an image forming apparatus; a charging power supply configured to feed, with constant current control, a charging bias to be applied to the discharge electrode to deposit charge on a surface of the latent-image bearer by establishing the discharge between the discharge electrode and the latent-image bearer; a grid power supply configured to feed a grid bias to be applied to the grid electrode with constant voltage control; and a control unit configured to perform a grid determining process, the grid determining process determining a grid setpoint value, the grid setpoint value being an output setpoint value for the constant voltage control of the grid bias, characterized in further comprising a surface potential detector configured to output a result of detecting a surface potential of the latent-image bearer where charge is deposited by the discharge, wherein the control unit is configured to perform a charging-current determining process, the charging-current determining process determining a charging-current setpoint value, the charging-current setpoint value being an output setpoint value for the constant current control of the charging bias, based on a difference between the result of detection output from the surface potential detector and the grid setpoint value at predetermined timing.