I am carrying out some research on CCDs for a h/w design project that I have coming up that would include a 2D bar-code scanner module. I know that there are ready made modules available and thus there is no need to design one ourselves, still I would like to know a little more about barcode scanners. To that effect I have a few questions
Are the CCDs used in bar-code scanners, especially for 2D scanners, similar to those used in cameras?
If not, what is the exact difference?
A pointer to specific brands and/or manufacturers would also be nice.
Best Answer
Simply put, CCDs are CCDs and all operate on the same principle. However, they are not all created equal. I would imagine that CCD's used for barcode application only detect luminance information and not colour. Thus they are simpler and cheaper, as the amount of sensing elements are lower.
(Why lower? Well a colour CCD uses 4 subsensors for each pixel: blue, red and 2 green.)
Scanners may include some "cheats" such as having a 1 dimentional CCD and scanning over the target at a high rate of speed. Others may have full 2D sensors.
A nice example of a 2D black and white CCD can be found in optical mice. You can read here about turning a mouse into a simple scanner (more interesting than practical)