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1. a device, usually electronic, used to measure or sample the distribution of some quantity or condition in a particular system, region, or area
2. any of various devices used in medical diagnosis to obtain an image of an internal organ or part
3. short for optical scanner
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005


(computer science)
A device that converts an image of something outside a computer, such as text, a drawing, or a photograph, into a digital image that it sends into the computer for display or further processing.
That part of a facsimile transmitter which systematically translates the densities of the elemental areas of the subject copy into corresponding electric signals.
Any device that examines an area or region point by point in a continuous systematic manner, repeatedly sweeping across until the entire area or region is covered; for example, a flying-spot scanner.
A device that automatically samples, measures, or checks a number of quantities or conditions in sequence, as in process control.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


An input device that takes in an optical image and digitises it into an electronic image represented as binary data. This can be used to create a computerised version of a photo or illustration.

A scanner may be linked to optical character recognition software allowing printed documents to be converted to electronic text without having to type them in at a keyboard.


This article is provided by FOLDOC - Free Online Dictionary of Computing (


(1) A synonym for antivirus program.

(2) A smartphone application that reads barcodes. See mobile tagging.

(3) An optical device that reads a printed page or transparency and converts it into a graphics image for the computer. The scanner does not recognize or differentiate in any manner the content of the material it is scanning. Everything is converted into a bitmapped image, which is a pattern of dots. See bitmapped graphics.

Optical Character Recognition (OCR)
Optical character recognition systems use scanners to capture printed text and convert it into computer-readable characters for editing. See OCR and document scanner.

Scanners and Cameras
Scanners are similar to digital cameras, except cameras can focus into infinity. Desktop scanners have physical dimensions that determine the size and bulk of the material that can be scanned. Automatic feeders are used to scan stacks of paper, typically for OCR jobs.

Scanners are rated in dots per inch (dpi), whereas cameras are rated in total pixels. Both scanners and cameras have an optical resolution (the real lens resolution) and an interpolated resolution computed by software. The higher the optical, the better.

Scanners are also rated by the maximum color depth of each pixel (how many colors can be stored). At minimum, scanners support 24-bit color, and many go up to 48 bits. See optical resolution, interpolated resolution, 4K resolution, document scanner, flatbed scanner, sheet-fed scanner, handheld scanner, drum scanner, slide scanner, photo scanner and digital camera.

Desktop Scanners
The flatbed scanner is the most common desktop scanner. A transparency adapter provides a light source from the top for scanning 35mm slides and film negatives. Slide scanners are specialized for only slides and film (see slide scanner).

High-End Drum Scanner
Drum scanners are used for commercial graphics production and applications that require the highest quality scanning (see drum scanner). This earlier Howtek scanner provided an optical resolution up to 4,000 dpi. (Image courtesy of Howtek, Inc.)
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References in periodicals archive ?
health authorities have already confirmed that back scatter body scanners pose a negligible risk to human health," the Daily Mail quoted a spokesperson for the Manchester airport as saying.
We consistently receive feedback from our customers that have transitioned to a network scanner, that the fast scanning speeds, compact size and ease of use has allowed them to streamline their document capture workflow.
Furthermore, O-Arm CT Scanner architecture holds the major share in the market followed by C-Arm architecture due to its broad range of scientific application such as its growing usage majorly during spinal tool replacement with visceral, neurological and vascular injuries which is anticipated to the drive the market demand.
Purchased at a cost of Rs 202 million, the advanced scanner is capable of conducting more than 100 scans a month and it will considerably improve treatment for cancer patients at the hospital.
Kuo remains optimistic on the wider adoption of in-display fingerprint scanners since it's considered as an integral feature for true full-screen smartphones.
MRI scanners are used to take images of all parts of the body including the brain, spinal cord, heart and blood vessels and internal organs such as the liver, womb, prostate gland and gall bladder.
Most popular, high-feature scanners cost over USD 20,000 with some intraoral scanners such as those offered by companies like Sirona exceeding over USD 40,000.
We also used 225 of the test cases included in the Web Application Vulnerability Scanner Evaluation Project (WAVSEP) to clearly understand the accuracy weaknesses of the four evaluated scanners (see Table 3).
Jain and his biometrics team were studying how to test and calibrate fingerprint scanners commonly used across the globe at police departments, airport immigration counters, banks and even amusement parks, Science Daily reported.
The new scanner, according to the company, fits comfortably on a finger and uses Bluetooth technology to connect to a range of computing devices such as PCs, laptops, tablets, vehicle-mounted computers, rugged mobile computers and smartphones.
The leaked images, obtained by Android Authority, showed that the "Lock screen and security" settings page on the Galaxy Note 7 will have a new option below "Fingerprints," called "Irises." Once the user taps "Irises," a disclaimer will pop up, running through a long list of limitations of the iris scanner.
SecureLink debuts in the form of a small external attachment that adds network addressability so the scanner can be driven from a browser on another network-connected device.