Patent ID: 7386262
Filing Date: 2008-06-10
Classification: G03G

Abstract:
1. A belt driving control apparatus, the belt driving control apparatus having an endless belt, a driving roller driving the endless belt, a driving motor driving the driving roller, at least one idler roller being dependent on the endless belt, and an encoder attached to one of the idler roller, the belt driving control apparatus having a structure where a control target value of the driving motor is set so that an effective speed of the endless belt is constant and the driving motor is drive-controlled so that the control target value is satisfied, the belt driving control apparatus comprising: a mark detection part configured to detect a mark provided on the endless belt as a standard position; an angular displacement error detection part configured to detect an angular displacement error of the encoder generated by thickness variations of the endless belt; a first computing part configured to calculate a maximum amplitude and a phase of a wave of the thickness variations of the endless belt at the mark from the angular displacement error of the encoder obtained by the angular displacement error detection part; a second computing part configured to calculate correction data corresponding to a distance from the mark based on a value stored in a non-volatile memory; a storage device configured to store the calculation result of the first computing part and the correction data; and a driving motor control part configured to make speed variations due to thickness displacement of the endless belt stable by adding the correction data to the control target value for driving control at the time of driving the driving motor; wherein the first computing part implements a moving average process and a revolution average process of data of the angular displacement error of the encoder detected by a plurality of revolutions of the endless belt so that data of the angular displacement error of the encoder of one revolution of the belt is calculated, and a phase and a maximum amplitude at the mark of the wave of the thickness displacement of the endless belt are calculated from data of the calculated angular displacement error.