Image forming apparatus

An image forming apparatus having a first motor and a second motor which are rotated in response to phase switching signals, comprising:

• a position detecting unit which detects a rotational position of each of said plurality of motors;
• a time lag information calculating unit which calculates time lag information for changing a phase switching time between said motors;
• and
• a phase difference control unit comprising:
• a time difference information output unit which receives a first phase switching signal obtained from position detection information of said first motor and a second phase switching signal obtained from position detection information of said second motor and outputs a time difference information signal by using said first phase switching signal and said second phase switching signal:
• a first time lag information output unit which outputs first time lag information from said time difference information signal and a preliminarily-stored phase difference to be provided between the motors:
• and
• a time lag dividing unit which divides said first time lag information and outputs a time lag signal wherein said time lag dividing unit outputs said time lag signal from a preset maximum delay phase difference and said first time lag information, and wherein
• the phase difference control unit which, when power noise due to phase switching signals generated from the rotational position information of each of the motors is multiplexed with the time lag information of each of the motors, is configured to delay the phase switching signal of at least one of said plurality of motors based on said time lag information so to shift the corresponding power noise and outputs a delayed phase switching signal.