APPARATUS AND METHOD FOR CONTROLLING CHARGING VOLTAGE OF ELECTRO-PHOTOGRAPHY SYSTEM

摘要

PURPOSE: An apparatus and method for controlling charging voltage of an electro-photography system are provided to control the charging voltage without using a surface potential sensor. CONSTITUTION: An apparatus for controlling charging voltage of an electro-photography system includes a high-voltage supply(33), a photosensitive drum(38), ampere meters(37,39), a calculator(34), and a controller(40). The high-voltage supply provides high voltage to a corona wire(30) and a conductive shield(32). The photosensitive drum is charged according to accumulation of corona ions ionized between the corona wire and conductive shield according to the high voltage. The ampere meters detect corona current and shield current that respectively flow to the corona wire and conductive shield. The calculator calculates charging current flowing into the photosensitive drum on the basis of the corona current and shield current sensed by the current sensor. The controller controls the high voltage supplied from the high-voltage supply according to the calculated charging current.