optical scanner

(redirected from optical scanners)
Also found in: Dictionary.

optical scanner

[′äp·tə·kəl ′skan·ər]
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


(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.)
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
Nutfield Technology has been designing and manufacturing advanced galvanometer-based optical scanners, scan heads, laser scan kits, and scan control software and hardware since 1997.
The 66-year-old physician cited complaints from Detroit election officials who reported that 87 optical scanner voting machines failed on Election Day in addition to discrepancies in ballot handling and documented vote counts.
Two different optical scanners were used for contactless digitising the case study.
Although Oregon voters mail in, their ballots, all counties in the state tally votes with optical scanners. The article's graphic shows, by means of colors, which were the last Oregon counties to switch from punch-card readers to scanners for ballot counting.--P.
From sharpened stones and fire-making tools to therapeutic cloning and optical scanners, author David Stewart hits humanity's high points in breezy, paragraph-sized text blocks accompanied by color illustrations.
The claim by lobbyists about the cost advantages of a DRE is that they would cost "roughly $7,500 an election district." "Omitted have been the differences in storage, training and transportation costs for DRE systems over paper ballot and optical scanners. Computers need to be kept in a climate controlled environment." Bo added the optical scanner does not need that type of storage control.
With the threat of terrorism, security systems and equipment (specialized sensors/alarms, optical scanners for identification, and video surveillance) have become commonplace.
The span of the joint project is limited because the typefaces printers used before 1836 are too difficult for optical scanners to read, and because copyright restrictions apply to papers published after 1923; however, USA Today reports that the Library of Congress is undertaking a separate, broader project to preserve records of U.S.
The following policy also applies to take full advantage of the inherent life cycle management efficiencies of this technology: Beginning in FY 2007 and beyond--only RFID-capable AIT peripherals (e.g., optical scanners, printers used for shipping labels) will be acquired when these peripherals support RFID-capable business processes.

Full browser ?