Patent ID: 9298141
Filing Date: 2016-03-29
CPC Classification: G03G

Claim Text:
1. An image heating device comprising: a first heating element; a second heating element configured to be driven independently from the first heating element; a temperature detection element configured to detect a temperature; and an electric power controller configured to control electric power to be supplied to the first and second heating elements for each control cycle corresponding to a period including a plurality of consecutive hall cycles of alternate current in accordance with a temperature detected by the temperature detection element, wherein the electric power controller controls electric power such that a current is supplied to both the first and second heating elements, wherein the current includes a waveform having first half cycles, in which current is supplied or not supplied in entire half cycles of alternate current, and a second half cycle, in which current is supplied to portions of the half cycles of alternate current in a mixed manner, wherein the electric power controller sets a first control pattern in which electric power is controlled such that the first half cycle supplied to the first heating element and overlaps with the second half cycle supplied to the second heating element and in the half cycles of same phases, and the second half cycle supplied to the first heating element overlaps with the first half cycle supplied to the second heating element in the half cycles of the same phases during the control cycle; and wherein the electric power controller sets a second control pattern in which electric power is controlled such that the first half cycles supplied to the first and second heating elements overlap with each other and the second half cycles supplied to the first and second heating elements overlap with each other in the half cycles of the same phases during the control cycle.