Microscopy Primer
Light and Color
Microscope Basics
Special Techniques
Digital Imaging
Confocal Microscopy
Live-Cell Imaging
Photomicrography
Microscopy Museum
Virtual Microscopy
Fluorescence
Web Resources
License Info
Image Use
Custom Photos
Partners
Site Info
Contact Us
Publications
Home

The Galleries:

Photo Gallery
Silicon Zoo
Pharmaceuticals
Chip Shots
Phytochemicals
DNA Gallery
Microscapes
Vitamins
Amino Acids
Birthstones
Religion Collection
Pesticides
BeerShots
Cocktail Collection
Screen Savers
Win Wallpaper
Mac Wallpaper
Movie Gallery

Interactive Flash Tutorials

CCD Operation

Explore the operation of a charge-coupled device (CCD) imaging semiconductor with this interactive Flash tutorial. Modern CCDs consist of a light-sensitive sandwich of insulating silicon dioxide positioned beneath an array of photodiodes and above an array of metal electrodes.

Photons from an illumination source (shown in the tutorial as a wavy red arrow) first collide with silicon atoms in the body of the CCD, releasing negatively charged electrons. These electrons are trapped in the pixel array with a positive charge generated by the electrode array positioned beneath an insulating layer of silicon dioxide. In this manner, light intensity from an object being imaged is captured in terms of the number of electrons contained in each pixel.

The second stage consists of reading the number of electrons stored in each pixel, one at a time, until the entire array has been translated to produce a video signal. This is accomplished by a ripple voltage that runs along the electrodes of each pixel column, dragging the electrons from one pixel to another. The electrons positioned in pixels adjacent to the horizontal readout register are transferred onto this row, then sequentially read in a serial manner until the contents of the entire CCD has been recorded. When all columns have emptied into the readout register and been converted into a continuous waveform, the process repeats itself.

Contributing Authors

Mortimer Abramowitz - Olympus America, Inc., Two Corporate Center Drive., Melville, New York, 11747.

Brian O. Flynn and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.


BACK TO PHOTOMICROGRAPHY

Questions or comments? Send us an email.
© 1998-2013 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last modification: Wednesday, Jul 21, 2004 at 10:59 AM
Access Count Since June 5, 2000: 26361
Visit the websites of our partners in digital imaging education:
Visit the Olympus Microscopy Resource Center website. Visit the QImaging website.