APPARATUS FOR DEVELOPING DUPLEX ELECTROPHOTOGRAPHS AND TONER IMAGE CONCENTRATION CONTROLLING METHOD THEREFOR

摘要

PURPOSE: An apparatus for developing duplex electrophotographs and a toner image concentration controlling method therefor are provided to enable a concentration controller to control concentration of a toner image according to a measured resistance value when a printing media tray is converted into a closed state from an open state, thereby exactly controlling the concentration of the toner image. CONSTITUTION: A printing media tray(111) classifies printing media by kind, and accumulates the classified printing media. A tray open/shut sensor(125) senses whether the printing media tray(111) is open/shut. A transfer roller(119) transfers a toner image to the printing media. A resistance measurer measures resistance values of the printing media passing through the transfer roller(119). A concentration controller controls concentration of the toner image transferred to the printing media according to the measured resistance values. If the printing media tray(111) is converted into a closed state from an open state, the concentration controller controls the concentration of the toner image according to the resistance values measured by the resistance measurer.