A flatbed is a type of scanner or copier that uses a flat, glass surface for scanning documents or other objects. Most flatbed scanners have an adjustable lid that can be raised to allow magazines, books, and other thick objects to be scanned. This is a significant benefit over sheet-fed scanners or copiers (sometimes referred to as automatic document feeders, which can only accept paper documents.
Flatbed scanners and copy machines range in size from standard letter size (8.5"x11") to legal size and beyond. For example, a scanner used to scan architectural blueprints may be the size of several letter-size scanners. Because of their large size capacity and ability to scan thick objects, flatbed scanners are more versatile than sheet-fed scanners. However, they cannot automatically feed pages into the scanner, which means scanning multiple pages can be a time-consuming process. For this reason, some scanners and copy machines include both a flatbed scanning surface for large or thick objects, and an ADF for feeding multiple pages at once.