Editing Image scanner (section)

{{Short description|Device that optically scans images, printed text}}
[[File:Epson V850 scanner open 20230920.jpg|thumb|A flatbed scanner ([[Epson]] Perfection V850 Pro) with its lid open. Documents or images are placed face-down on the glass bed (the platen).]]
An '''image scanner''' (often abbreviated to just '''scanner''') is a device that optically scans images, printed text, [[handwriting]], or an object and converts it to a [[digital image]]. The most common type of scanner used in the home and the office is the '''flatbed scanner''', where the document is placed on a glass bed. A '''sheetfed scanner''', which moves the page across an image sensor using a series of rollers, may be used to scan one page of a document at a time or multiple pages, as in an [[automatic document feeder]]. A '''handheld scanner''' is a portable version of an image scanner that can be used on any flat surface. Scans are typically downloaded to the [[computer]] that the scanner is connected to, although some scanners are able to store scans on standalone [[Flash memory|flash media]] (e.g., [[memory card]]s and [[USB flash drive|USB drives]]).

Modern scanners typically use a [[charge-coupled device]] (CCD) or a [[contact image sensor]] (CIS) as the image sensor, whereas [[drum scanner]]s, developed earlier and still used for the highest possible image quality, use a [[photomultiplier tube]] (PMT) as the image sensor. [[Document camera]]s, which use commodity or specialized high-resolution cameras, photograph documents all at once.