Apparatus and method of controlling power supply to heating roller and phase control circuit corresponding to the apparatus and method

Abstract

A method and an apparatus to control power supplied to a heating roller and a phase control circuit corresponding to the method or the apparatus. The phase control circuit may include an examination unit to compare levels of a sine wave having a predetermined first period and a switching signal to increase and decrease repeatedly according to a predetermined second period, and a phase control signal generation unit to generate a phase control signal having a non-zero in intervals of time sections including a time when levels of the switching signal and the sine wave which is in a decreasing section are equal to each other during a time period when the level of the sine wave is zero, and a time when levels of the switching signal and the sine wave which is in an increasing section are equal to each other during a time period when the level of the sine wave is zero.

Dependencies are inferred from the claim text.