Patent ID: 7639963
Filing Date: 2009-12-29
Classification: G03G

Abstract:
1. An image forming apparatus having a thermal fixing unit adapted to fix a transfer image upon a recording medium by electrothermally generated heat, comprising: a capacitive unit adapted to accumulate electric power at a predetermined charging level; an inputted current reducing unit adapted to reduce a current inputted from an external power source using electric power charged in the capacitive unit together with electric power from the external power source when warming up the thermal fixing unit; a first charging unit adapted to charge the capacitive unit at a first charging rate capable of recharging the capacitive unit within a warming up section; a second charging unit adapted to charge the capacitive unit at a second charging rate that is lower than the first charging rate and greater than a natural power discharge rate of the capacitive unit maintaining a charged level; a charge switching control unit adapted to switch a power source charging the capacitive unit from the first charging unit to the second charging unit when the image forming apparatus transitions into an energy saving standby mode, and to return the power source charging the capacitive unit from the second charging unit to the first charging unit when the image forming apparatus returns from the energy saving standby mode, wherein the second charging unit includes a switching unit adapted to switch any one parameter of a constant current value, a constant voltage value, and a constant power value with respect to the first charging unit, and wherein the second charging unit comprises a constant voltage charging unit configured by serially connecting a constant voltage supply and an impedance unit to the capacitive unit.