How a barcode scanner works

The structure of a barcode scanner is usually as follows: light source, receiving device, photoelectric conversion component, decoding circuit, and computer interface.

The basic working principle of a barcode scanner is: the light emitted by the light source shines on the barcode symbol through the optical system, and the reflected light is imaged on the photoelectric converter through the optical system to generate an electrical signal, which is generated after the signal is amplified by the circuit An analog voltage, which is proportional to the light reflected on the bar code symbol, and then filtered and shaped to form a square wave signal corresponding to the analog signal, which is interpreted by the decoder as a digital signal that can be directly accepted by the computer.

Common flat-panel barcode scanners generally consist of a light source, an optical lens, a scanning module, an analog-to-digital conversion circuit, and a plastic case. It uses a photoelectric element to convert the detected light signal into an electrical signal, and then the electrical signal is converted into a digital signal by an analog-to-digital converter and transmitted to a computer for processing. When scanning an image, after the light source shines on the image, the reflected light passes through the lens and converges on the scanning module. The scanning module converts the light signal into an analog digital signal (that is, the voltage, which is the intensity of the received light (Relevant), and point out how dim the image is. At this time, the analog-digital conversion circuit converts the analog voltage into a digital signal and sends it to the computer. The colors are quantized using the 8, 10, and 12 bits of the three RGB colors, and the signal is processed into the image output of the above-mentioned number of bits. If there are higher quantization digits, it means that the image can have richer levels and depths, but the color range has exceeded the recognition ability of the human eye, so within the resolvable range, for us, higher-digit barcode scanning The effect of the scanner scanning is smooth color connection, and you can see more details of the picture.