What is a feeder?
In printing, a feeder is any mechanism that delivers media into the device one sheet at a time. On a printer that means the paper trays and the manual feed. On a scanner, copier or multifunction device (MFD) it usually means the automatic document feeder (ADF), which pulls a stack of originals past the scanner so you don't have to place each page on the glass.
Types of feeders
- Paper tray (cassette): the main supply. Adjustable guides keep the stack square, and some printers detect the paper size from the guide position; others rely on the tray setting.
- Manual or bypass feed (multipurpose tray): a fold-out tray or slot for envelopes, labels, card stock and single odd-size sheets. On many printers it gives media a straighter path.
- Optional high-capacity trays: extra feeders added under the printer. The driver has to know they're installed before users can choose them.
- Rear sheet feeder: common on inkjet printers, where paper stands upright at the back.
- ADF: on top of an MFD or document scanner. A reversing ADF flips each page to scan the second side; a single-pass duplex ADF has a sensor for each side and scans both at once.
How sheets get picked
Every feeder relies on the same three parts. The pickup roller grabs the top sheet, a separation pad (or separation roller) holds back the sheets underneath so only one goes through, and feed rollers carry it into the device. When these rubber parts wear or get coated with paper dust they lose grip, and the feeder starts misbehaving.
Common feeder problems
| Symptom | Likely cause |
|---|---|
| Paper not feeding | Worn or dirty pickup roller, empty or unseated tray, tray set to the wrong size or type |
| Several sheets at once (multi-feed) | Worn separation pad, overfilled tray, damp or static-charged paper |
| Skewed pages or jams | Guides not touching the stack, curled or damaged paper, mixed paper types |
| Vertical line on ADF copies only | Dirt on the ADF scanning glass strip; flatbed copies come out clean |
Don't send staples, paper clips, sticky notes, photos or torn pages through an ADF; use the flatbed for those. Clean rollers with a lint-free cloth dampened with water or the cleaner the manufacturer recommends, and replace them (often sold as a roller kit) when cleaning no longer helps.
For the CompTIA A+ exam
Core 1 (220-1201) objective 3.8 lists the feeder among inkjet parts, and objective 3.7 includes tray settings and the ADF and flatbed scanner on multifunction devices. Objective 5.6 covers paper not feeding, multipage misfeeds and paper jams. If a scenario says the originals are fragile, bound or stapled, the answer is the flatbed, not the ADF.