Patent ID: 8843011
Filing Date: 2014-09-23
Classification: G03G

Abstract:
1. An image-forming apparatus, comprising: a fixing unit for fixing a toner image onto paper, using a heat generator for generating heat upon receiving electric power supplied to the image-forming apparatus; a load that is used in the execution of a job; a power source circuit section for generating voltage for the load on the basis of the electric power supplied to the image-forming apparatus and supplying electric power to the load; a fixation electrical current detecting body for detecting the magnitude of a fixation electrical current, which is an electrical current that flows to the fixing unit; a total electrical current detecting body for detecting the magnitude of the total electrical current of the image-forming apparatus, the total electrical current being the sum of the electrical current that flows to the fixing unit and an electrical current that flows through the load; a storage unit for storing electrical current change amount data establishing an amount of change in the magnitude of the total electrical current relative to an amount of change in a phase at which the heat generator starts to be energized, for each value of the power factor of the fixing unit; and a fixation control unit for: controlling a drive circuit for starting and stopping energizing of the heat generator, carrying out a phase control for altering the phase in which energizing in a period of voltage being applied to the heat generator is activated; recognizing the magnitude of the fixation electrical current on the basis of an output of the fixation electrical current detecting body and finding a value indicative of the power factor of the fixing unit; recognizing the magnitude of the total electrical current on the basis of an output of the total electrical current detecting body; and controlling the drive circuit to alter the phase at which the heat generator starts to be energized, on the basis of the value indicative of the power factor thus found, the state of the image-forming apparatus, and the electrical current change amount data, so that the total electrical current approaches a target value.