Belt moving device and image forming apparatus including the same

An image forming apparatus comprising:

• an intermediate image transfer belt;
• a belt moving device for moving said intermediate image transfer belt with an output torque of a motor;
• and
• image forming means for forming an image in a plurality of colors on a sheet by controlling movement of said intermediate image transfer belt;
• said belt moving device comprising:
• a drive shaft configured to cause said intermediate image transfer belt to move;
• transmitting means for transmitting the output torque of the motor to said drive shaft;
• marker sensing means for sensing a marker, which is provided on said intermediate image transfer belt, to thereby determine a position of said intermediate image transfer belt in a direction of movement of said intermediate image transfer belt;
• rotation condition sensing means for sensing a rotation condition of said drive shaft;
• first correction information generating means for generating, based on an output of said marker sensing means, correction information for correcting the position of said intermediate image transfer belt in the direction of movement;
• second correction information generating means for generating, based on an output of said rotation condition sensing means, correction information for correcting a rotation condition of said drive shaft;
• and
• control means for controlling a movement of the motor in accordance with said correction information output from said first correction information generating means and said second correction information generating means.

An image forming apparatus comprising:

• an intermediate image transfer belt;
• a belt moving device for driving at least one of an intermediate image transfer belt and a sheet conveyance belt with an output torque of a motor;
• and
• image forming means for forming an image in a plurality of colors on a sheet by controlling movement of said intermediate image transfer belt;
• image forming means for forming an image in a plurality of colors on a sheet by controlling movement of said intermediate image transfer belt;
• said belt moving device comprising:
• sensing means for sensing a surface position of a subject of drive;
• and
• position control means for feeding back a surface position sensed by said sensing means to thereby cause a surface position of a subject of drive to follow a target position.

An image forming apparatus comprising:

• an intermediate image transfer belt;
• and
• a belt moving device for driving either one of an intermediate image transfer belt and a sheet conveyance belt with an output torque of a motor;
• and
• image forming means for forming an image in a plurality of colors on a sheet by controlling movement of said intermediate image transfer belt;
• said belt moving device comprising:
• rotation condition sensing means for sensing a rotation condition of an output shaft of the motor;
• and
• control means for feeding back a rotation condition sensed by said rotation condition sensing means to thereby cause a position of an output shaft of the motor to follow a target output shaft position such that a deviation of a surface position of said intermediate image transfer belt from a target surface position is canceled.