How scanners work

What is Scanner

• Scanner is operates on the principle of reflection. That is, when a light source falls on an image document, the incident light reflects.
• The reflection depends upon the color and size of the images in the document.

Flatbed scanners

• Flatbed scanners, also called desktop scanners, are the most versatile and commonly used scanners.
• Works like copy or Xerox machine. Flatbed is made up of glass pane and moving CCD array and two mirrors.

How it works

• There are four steps explain how it works.
1. A light source illuminates the document through the glass bed. The light source moves along a track as the document is being scanned.
2. The document is reflected into an angled mirror, which also moves along a track at the same speed.
3. The first mirror’s reflection is captured by a fixed mirror at the other end of the scanner.
4. The image from the fixed mirror is captured by a CCD (charge-coupled device) and can then be saved to a computer hard-drive.

• This is another way of looking at it, with a three-mirror setup.