Patent ID: 8376640

Claim:
A printing media feeding apparatus comprising: feeding means that includes a motor, a drive transmission mechanism which transmits a driving force of the motor, and a drive shaft to which the driving force is transmitted by the drive transmission mechanism, the drive shaft being rotated to feed or transport a printing media; detection means that has a portion which is mechanically connected to the drive shaft and detects the rotational speed of the drive shaft, wherein the detection means generates a plurality of pulse signals while the drive shaft is rotated in a feed direction and at least two of the pulse signals corresponding to rotation of the drive shaft in the feed direction while one line of image information is being printed, the pulse signals providing an indication of rotational speed; and control means for controlling the motor, the control means controlling the motor based on an input from the detection means so that the rotational speed of the drive shaft becomes substantially constant, and as a result, the speed of the printing media being fed by the feeding means also becomes substantially constant, wherein the control means further includes a moving-average circuit that directly receives an output of a Kalman filter and a comparing control circuit receives an output from the moving-average circuit, the comparing control circuit compares the output from the moving-average circuit with reference data stored in a memory and provides a control output for controlling the motor based on a comparison result, and further wherein the comparing control circuit determines a rotational speed fluctuation component and controls the stepping motor to substantially eliminate or reduce the rotational speed fluctuation component.