US 2008/0075494 A1 · IMAGE FORMING APPARATUS AND POWER SUPPLY CONTROL METHOD THEREOF

Abstract

An image forming apparatus having a thermal fixing unit reduces a current inputted from a commercial power source using electric power charged in the capacitive when warming up the thermal fixing unit. The apparatus comprises a first charging unit to charge the capacitive unit at a first charging rate, and a second charging unit to charge the capacitive unit at a second charging rate lower than the first charging rate and greater than a natural power discharge rate of the capacitive unit. A charge switching control unit switches 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 returns 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.

Claims16

Dependent claims

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;
and
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.

3 more elements

A method of controlling a power supply of an image forming apparatus having a thermal fixing unit adapted to fix a transfer image upon a recording medium by electrothermally generated heat, said method comprising:

an inputted current reducing step of reducing a current inputted from an external power source using electric power charged in a capacitive unit adapted to accumulate electric power at a predetermined charging level together with electric power from the external power source, when warming up the thermal fixing unit;
a first charging step of charging the capacitive unit at a first charging rate capable of recharging the capacitive unit within a warming up section;
a second charging step of charging 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 the charged level;
and
a charge switching control step of switching a charging step of charging the capacitive unit from the first charging step to the second charging step when the image forming apparatus transitions into an energy saving standby mode, and returning the charging step of charging the capacitive unit from the second charging step to the first charging step when the image forming apparatus returns from the energy saving standby mode.

2 more elements

Dependencies are inferred from the claim text.

Image forming apparatus and power supply control method thereof

Life of this patent

Image forming apparatus and power supply control method thereof

Life of this patent

Abstract

Claims16