Sheet conveying device, and image forming apparatus including same

A sheet conveying device, comprising:

• a drive source;
• a drive roller driven by the drive source;
• a driven roller to press against the drive roller and rotate with the drive roller;
• an angular velocity detector to detect an angular velocity of the drive roller;
• a timing estimation unit to estimate a timing when a sheet-type recording medium enters between the drive roller and the driven roller;
• and
• a controller to control the drive source based on detection results obtained by the angular velocity detector,
• the controller including:
• a feedback control unit to perform feedback control based on data obtained by the angular velocity detector, and
• a feed-forward control unit to perform feed-forward control based on data obtained by the timing estimation unit,
• wherein a feed-forward target value stored in the controller is corrected by detected speed variation data,
• wherein based on the detected speed variation data during the feed-forward control, a feed-forward correction value is obtained through processes of removing offset from detected speed variation data, inversing positive and negative values, and cutting off a part including the speed variation, and
• wherein the obtained feed-forward correction value is added to the feed-forward target value, thereby correcting the feed-forward target value.