Our common flat-panel scanner is generally composed of scanning module, optical lens, light source, analog digital conversion circuit and plastic shell. It uses optoelectronic components to convert the detected optical signals into electrical signals, and then the electrical signals are converted into digital signals by analog-to-digital converters and transmitted to the computer for processing. When an image is scanned, the reflected light from the light source shining on the image converges through the lens to the scanning module, which converts the light signal into an analog digital signal (i.e. voltage, which is related to the intensity of the received light), and indicates the grey degree of that image. At this time, analog to digital conversion circuit converts analog voltage to digital signal and sends it to the computer.
The above laser scanner has introduced the working principle and the price of the scanner in the market. The price of a scanner depends on the type of scanner, but the same type of scanner works the same way.