The parts of a document scanner

A document scanner with a feeder has four main groups of parts: the feeder that moves paper, the imaging parts that capture each page, the sensors that keep paper moving safely, and the electronics that run it all. Knowing which part does what makes it easier to fix a problem and find the right replacement.

The feeder

• Input tray and guides hold the stack straight; feeders and output trays are sold for many models.
• Pick roller pulls the top sheet off the stack.
• Separation pad or brake roller holds back the next sheet so only one page goes through.
• Feed rollers carry the page past the camera. These rollers are the parts that wear out; see rollers and pads and consumables kits.

The imaging parts

• Glass that the page passes over, and that the sensor looks through.
• Image sensor: a CIS (contact image sensor) or a CCD with mirrors and a lens. Duplex scanners have one for each side of the page.
• Light source: LEDs in current scanners, or lamps in older ones.

Sensors and electronics

Sensors detect when paper is present, when a page jams and when two sheets feed together. The control board runs the scanner and connects to the computer through USB or network cables. Options such as imprinters attach to the paper path on many production models.

Finding a part

Every scanner's page on ScanStore has a List parts link that shows the parts made for that model. See also finding the right scanner spare parts.