Patent ID: 7853189

Claim:
A belt moving device comprising: an endless belt; a drive roller for moving/stopping the endless belt; at least one opposing roller disposed in a position opposing the drive roller; a motor for rotating the drive roller; a position detecting device that detects a position of the endless belt; a moving device that moves at least one of the rollers to a vertical direction target rotation position; and a belt shift controller that controls belt shift in accordance with a traveling speed of the endless belt while the endless belt is in motion, wherein, in the belt shift controller, a deviation obtained by subtracting a belt shift position from a target shift position is calculated using a first controller A, a value thereof is multiplied by a shifting amount per unit time corresponding to a reference belt shift position variation rate, a value thereof is subtracted from a value obtained by subtracting the belt traveling speed from a reference belt traveling speed for determining the reference belt shift position variation rate and the belt traveling speed, and a result thereof is calculated as a position control value, and by using the position control value to perform vertical direction drive control on the movable roller, the roller is moved in the vertical direction by the moving device, whereby the endless belt is subjected to position control.