World Library  
Flag as Inappropriate
Email this Article

Contact image sensor

Article Id: WHEBN0001242563
Reproduction Date:

Title: Contact image sensor  
Author: World Heritage Encyclopedia
Language: English
Subject: Image scanner, CIS, Optical devices, List of sensors, Speed sensor
Collection: Optical Devices
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Contact image sensor

CIS of a flatbed scanner

Contact Image Sensors (CIS) are image sensors used in flatbed scanners almost in direct contact with the object to be scanned. CCDs, often used for this application, use mirrors to bounce light to a stationary sensor. CISs are much smaller than CCDs, use typically a tenth as much power, and are particularly suitable for low power and portable applications, often powered over USB.[1]

Scanner unit with CIS. A: assembled, B: disassembled; 1: housing, 2: light conductor, 3: lenses, 4: chip with two RGB-LEDs, 5: CIS

A CIS typically consists of a linear array of detectors, covered by focusing lenses and flanked by red, green, and blue LEDs for illumination. The use of LEDs allows the CIS to be highly power efficient, allowing scanners to be powered through the minimal line voltage supplied via a USB connection. CIS devices typically produce lower image quality compared to CCD devices; in particular, the depth of field is greatly limited, which poses a problem for material that is not perfectly flat. However, a CIS contact sensor is smaller and lighter than a CCD line sensor, and allows all the necessary optical elements to be included in a compact module, thus helping to simplify the inner structure of the scanner. With a CIS contact sensor, the scanner can be portable, with a height of only around 30 mm. CIS is both a key component of, and widely used in, scanners (especially portable scanners), electrographs, bar code readers and optical identification technology.

References

  1. ^ "Canon CIS technology overview". Retrieved Jan 25, 2012. 


This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.