barcode recognition is performed by scanning with barcode scanner (also called barcode reader, barcode scanner and barcode reader) to obtain a set of reflected light signals, which are converted into a set of electronic signals corresponding to lines and blanks through photoelectric conversion, and then decoded and restored to corresponding alphanumeric characters.

because objects of different colors have different wavelengths of reflected visible light, white objects can reflect visible light of various wavelengths, while black objects absorb visible light of various wavelengths, so when the light emitted by the light source of the barcode scanner passes through the diaphragm and the convex lens 1 (as shown in the figure below) and shines on the black-and-white barcode, the reflected light is focused by the convex lens 2 and then shines on the photoelectric converter. Therefore, the photoelectric converter receives reflected light signals with different intensities corresponding to white bars and black bars, and converts them into corresponding electrical signals to be output to the amplification and shaping circuit, which converts analog signals into digital electrical signals, and then translates them into digital character information through the decoding interface circuit.

To sum up, it is the principle of barcode recognition. In the process of barcode recognition, there are many factors that may affect the recognition, such as light, barcode defacement, barcode grade, etc. In the process of barcode production, it is recommended to use professional barcode software. The barcode grade is guaranteed to be easy to recognize, and there are many types of barcodes supported.