Progressive Scan CCD
Is the newest type of bar code reader currently available and are camera based readers that use a small video camera to capture an image of a bar code. The reader then uses modern digital image processing techniques to decode the bar code. Much as video cameras do these scanners use the same CCD technology as in a CCD bar code reader except that instead of having a single row of sensors, a video camera has hundreds of rows of sensors arranged in a two dimensional array so that they can generate the image.
CCD image sensors
(Charge Coupled Device) readers use an array of hundreds of tiny light sensors lined up in a row in the head of the reader. The important difference between a CCD reader and a laser scanner is that the CCD reader is measuring emitted ambient light from the bar code whereas a laser scanner measures reflected light of a specific frequency originating from the scanner itself.