Patent ID: 9037009
Filing Date: 2015-05-19
Classification: G03G

Abstract:
1. An apparatus comprising: a first rotation member; a second rotation member that rotates while being in indirect contact with the first rotation member via a medium or being in direct contact with the first rotation member without the medium; a first drive motor that drives the first rotation member; a second drive motor that drives the second rotation member; a first control unit that controls the first drive motor to cause the first rotation member to rotate at a constant rotation frequency; a second control unit configured to control the second drive motor; a rotation frequency detection unit configured to detect a rotation frequency of the second drive motor, wherein the second control unit is further configured to determine, based on a detection result obtained by the rotation frequency detection unit when the first rotation member and the second rotation member are separated from each other, whether or not the second rotation member driven by the second drive motor satisfies a follower condition, to set to the second drive motor an input value which is supplied to the second drive motor for driving the second drive motor at a time when the detection result is obtained by the rotation frequency detection unit when the second rotation member satisfies the follower condition, and to change the input value and cause the rotation frequency detection unit to detect the rotation frequency of the second drive motor, and wherein the follower condition is defined so that the second rotation member follows the first rotation member rotating at a constant rotation frequency when the first rotation member and the second rotation member are in contact with each other, a first determination unit that determines whether or not a rotation frequency of the second drive motor has departed from a predetermined first threshold range; and a correction unit that, when the rotation frequency of the second drive motor has departed from the first threshold range, corrects as the input value an input voltage applied to the second drive motor or a PWM value until the rotation frequency of the second drive motor falls within the first threshold range.