Scanner

canner may refer to a number of technological devices. From them, Image scanner, a general-purpose device which digitizes a two-dimensional image. In computing, a scanner is a device that analyzes an image (such as a photograph, printed text, or handwriting) or an object (such as an ornament) and converts it to a digital image. Most scanners today are variations of the desktop (or flatbed) scanner The flatbed scanner is the most common in offices.
The scanning or digitization of paper documents for storage is quite different from the scanning of pictures for reproduction though it uses some of the same technology. While document scanning can be done on general-purpose office scanners, in major operations it is performed on dedicated, specialized scanners, manufactured by companies like Canon, Fujitsu, Kodak, and others.

Handheld Scanner

Hand-held scanners, where the device is moved by hand, were briefly popular but are now not used due to the difficulty of obtaining a high-quality image. Both the desktop and handheld types of scanners use charge-coupled device (CCD) or Contact Image Sensor (CIS) as the image sensor, whereas older drum scanners use a photomultiplier tube as the image sensor.

Document Scanner

Document scanners have document feeders, generally larger than those found on copiers or all-purpose scanners. They scan at lower resolution than other scanners, usually in the range 150dpi to 300dpi, since higher resolution is usually not needed and makes files much larger to store.

The scanning or digitization of paper documents for storage is quite different from the scanning of pictures for reproduction though it uses some of the same technology. While document scanning can be done on general-purpose office scanners, in major operations it is performed on dedicated, specialized scanners.

A lot of scans can be made at high speed, traditionally in grayscale but now in color as well. Sophisticated document scanners have either firmware of software that 'cleans up' scans as they are produced, eliminating accidental marks and sharpening type.

Many document scans are converted using OCR technology into searchable files. Most scanners use ISIS or Twain device drivers to scan documents into TIFF format so that the scanned pages can be fed into a document management system that will handle the archiving and retrieval of the scanned pages.

The biggest issues with document scanning are preparation and indexing. Preparation involves taking the papers to be scanned and making sure that they are in order, unfolded, without staples or anything else that might jam the scanner. This is a manual task and can be time consuming. Indexing involves associating keywords with files so they can be found later.

Barcode Scanner

Barcode Scanner or Barcode Reader, a device that reads the data encoded in a barcode. A barcode scanner is a computer peripheral for reading barcodes printed on various surfaces. Like a flatbed scanner, it generally consists of a light source, a lens and a photo conductor translating optical impulses into electrical ones. Additionally, nearly all barcode scanners currently produced contain decoder circuitry analyzing the barcode's image data provided by the photo conductor and sending the barcode's content to the scanner's output port.

Photo Scanner

A Photo Scanner is a type of image scanner. In essence, such a scanner is a mounted camera taking photos of a well-lit environment. Originally, such scanners were expensive and could only be found in archives and museums.

Flatbed scanners often come in contact with at least part of the object to be scanned. They also require books to be fully opened most of the time (there are some exceptions where the scanning surface ends at the edge of the flatbed scanner, so that a book can be opened partially). Both practices can damage rare books; especially opening a book 180 degrees can be damaging to its spine.

Photo scanners tend to touch fewer parts of a book, and provide an option of only opening a book partially. Scan your old family photos into your computer for safe-keeping or for e-mailing to relatives. Or scan your important documents and archive them to disk for backup.