Paper Feeder That Determines Necessity of Replacement of Retard Roller, and Image Forming Apparatus

An image forming apparatus comprising:

• a paper feeder that sends out a sheet;
• an image forming unit that forms an image on the sheet sent out by the paper feeder;
• and
• a control unit that controls the paper feeder and the image forming unit;
• wherein
• the paper feeder includes
• a lift plate that accommodates a plurality of sheets,
• a pickup roller that feeds out the plurality of sheets placed on the lift plate one by one,
• a feed roller that sends out the sheets that the pickup roller has fed out,
• a retard roller that separates a subsequent sheet from the sheet that has precedingly reached the feed roller when two or more of the sheets are fed out in an overlapped state by the pickup roller, and
• a rotation-count detection sensor that outputs a rotation-count detection signal, the rotation-count detection signal indicating a rotation count of the retard roller;
• the lift plate separates from the pickup roller before the control unit detects the rotation count of the retard roller;
• the feed roller is driven when the control unit detects the rotation count of the retard roller;
• the retard roller is in abutting contact with the feed roller when the control unit detects the rotation count of the retard roller;
• and
• the control unit detects the rotation count of the retard roller based on the rotation-count detection signal and determines whether replacement of the retard roller is necessary or not, based on the detected rotation count of the retard roller.