Bar code was first proposed by N.T.Woodland of the United States in 1949. In recent years, with the popularization of computer application, the application of bar code has been greatly developed. Barcodes can indicate the country of production, manufacturer, product name, production date, book classification number, starting and ending place, category and mailing date, so they are used in commodity circulation, book management, post and telecommunications management, etc.
Bar code is a graphic identifier composed of bars and spaces with different widths and reflectivity according to certain coding rules (coding system), which is used to represent a group of digital or alphabetic symbol information. That is, bar code is a group of parallel lines with different thicknesses and arranged at regular intervals. Common bar codes are composed of black bars (abbreviated as bars) and white bars (abbreviated as spaces) with great differences in reflectivity.
Due to the different wavelengths of visible light reflected by objects of different colors, white objects can reflect visible light of various wavelengths, while black objects absorb visible light of various wavelengths. When the light emitted by the light source of barcode scanner passes through the diaphragm and convex lens 1 to irradiate the black-and-white bar code, the reflected light is focused by convex lens 2 and irradiated 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. The widths of white bars and black bars are different, and the duration of corresponding electrical signals is also different. However, the electrical signal output by photoelectric converter corresponding to the bar and space of bar code is generally only about 10mV, so it cannot be used directly. Therefore, the electrical signal output by the photoelectric converter should be sent to the amplifier for amplification. The amplified electrical signal is still analog. In order to avoid false signals caused by defects and stains in bar codes, a shaping circuit should be added after the amplification circuit to convert analog signals into digital electrical signals so that the computer system can accurately interpret it.
The pulse digital signal of the shaping circuit is converted into digital and character information by the decoder. It can distinguish the coding system and scanning direction of bar code symbols by identifying the start character and the end character. By measuring the number of pulse digital electric signal 0, 1, the number of bars and spaces can be determined, and by measuring the duration of signal 0, 1, the width of bars and spaces can be determined. Therefore, the number of bars and spaces for bar code symbols and the corresponding width and code system can be obtained. According to the coding rules corresponding to the coding system, bar code symbols can be converted into corresponding digital and text information, and sent to the computer system for data processing through the interface circuit.
commodity bar code
Noun explanation:
Code system: barcode types include 13 code and 25 code, etc. The bar code in China is generally 13 code.
Method:
1. print parameter settings-> Print content settings-> Printer selection.
2. Double-click the product on the left to print the barcode.
3. Click [Print].
Commodity bar code's syndrome
Application materials: 1, code certificate; 2. Trademark registration certificate and its copy; 3. A copy of the business license and a copy; 4. Bank and account number; 5. Administrative official seal; 6. declaration form.
Handling procedures: the materials prepared by the enterprise shall be submitted to the provincial bar code center after being audited by the county-level bureau of quality and technical supervision.
Time limit for settlement: the materials are complete and the settlement is completed within 2 working days.