First of all, barcodes can be divided into one-dimensional barcodes and two-dimensional barcodes.
Figure: One-dimensional bar code-One-dimensional bar code only expresses information in one direction (generally horizontal direction), and does not express any information in the vertical direction. Its height is usually for the convenience of readers' alignment.
Two-dimensional code-the compression ratio is very good, and the reading method is also very different from one-dimensional code. It is the result of overall image processing and has further evolution.
1 barcode and barcode technology?
It is to express the data needed by the computer with bar code, and then convert the bar code data into data that the computer can automatically read. Bar code technology includes bar code compilation rules, bar code decoding technology, bar code printing technology, data communication technology and computer technology. It is a comprehensive technology. Any kind of bar code is composed of bars and spaces according to the pre-specified bar code rules and related technical standards. So far, there are more than forty bar code systems in the world. General cross code 25 can be used in logistics management, which is characterized by small space occupied by symbols and high information density. According to the data structure represented by bar code symbols and the data types that can be coded, we chose the cross 25 code in the production of air conditioners. The calculation method of bar code parity bit: the sum of one and three cycles in bar code data is weighted, and then the single digit of the sum is subtracted by 10, and the value obtained is the check data of the last bit of bar code. ?
2 barcode printing?
We have adopted M4800 thermal transfer barcode printer of SATO company in Japan, and the printing speed is 125mm/s, which has the advantages of flexible format, high image quality, low printing cost, convenient and reliable use and low failure rate. Its disadvantage is that the speed of this printer is a bit slow. It finishes bar code printing under the control of microcomputer. We are equipped with Japanese NEC PC 980INS/E20 portable computer (hard disk 20M, memory 40M). Bar code software is generally written in BASIC language, which is relatively simple. Considering the printer's ability to process Chinese characters, it is best to choose a bar code printer that can handle the secondary Chinese character library driven by ordinary microcomputer. In addition to the bar code, the bar code label should also include some necessary information, such as the manufacturer's trademark nameplate. It can also be completed by the manufacturer affixing a self-adhesive bar code paper tape on the printing carrier in advance. ?
3 bar code recognition?
Bar code recognition is accomplished by bar code reader, which can be divided into photoelectric scanner and decoder, and generally combined together. The MS720 reader of METROLOGIC Company in the United States is an online laser scanning reader with a scanning speed of 2,000 lines per second and a reliable scanning distance of 7 ~ 15 inch. There are 20 laser scanning lines in the scanning area, scanning the bar code in five directions, communicating with the computer through RS-232 interface, and selecting 12 bar code system by using DIP switch. The task of the decoder is to convert the signal generated by the scanner into data that can be recognized by the computer according to a certain bar code decoding principle, and then transmit it to the computer. The decoder function is usually realized by a microprocessor running corresponding software. The new barcode reader must be initialized according to the code system selected by the user: set barcode system → data transmission rate → barcode character length → define check bit → interface type between barcode reader and computer. The decoder can only recognize the barcode system selected by the user after initial programming. Generally, the bar code reader is connected to a microcomputer or computer terminal, as long as its output is connected to the parallel interface or RS-232 serial port on the microcomputer or terminal. ?
4 barcode verification?
In order to ensure the printing quality of bar codes, the printed bar codes should be checked regularly. Generally, a light pen barcode scanner can be prepared. For example, TBR- 1 100 or THS-2 1S can meet the requirements. If conditions permit, you can further prepare high-grade bar code testers such as CODEBARⅱII II: the light source wavelength is 633mm (red light) //900mm (infrared light), and the resolution is 2? 5μm, and its determination accuracy is 7? 5μm, the reflectivity measurement range is 0 ~ 100%, and the accuracy is 2%. If equipped with TP-32 printer, you can get a complete bar code test report. 5 The composition of the bar code application system (as shown in the figure) 6 Some experiences in the application of bar code technology began with 1994. We took the lead in using bar codes in air conditioning production and achieved one-time success. Over the past few years, I have accumulated some experience in popularization and application, mainly as follows:
(1) The importance of bar code knowledge popularization in promotion and use, so that managers and operators can understand the principle of bar code, why bar code technology and its role in computer systems should be applied, and the efficiency of bar code technology in production management and quality management should be applied, so that everyone can pay attention to this work ideologically. ?
(2) The application of bar codes must be closely coordinated by all departments. The application of barcode involves many links, such as product number, barcode printing, barcode pasting, barcode scanning and so on. Only through the division of labor and cooperation of production department, quality inspection department and equipment department can it be completed. Generally speaking, the bar codes of products are printed centrally. The specific printing quantity and paste can be completed by the production workshop, and the special person is appointed to operate and maintain it, and technical training is given to it. Bar code scanning should be completed by the quality inspection department. When the bar code information is wrong, it needs to be handled in time, and it needs the coordination and full support of the upper-level leaders. ?
(3) The use of bar code and effective management through computer system are the keys to the application of bar code technology. The purpose of applying barcode technology to management is not only to ensure the fast and accurate input of product information, to prevent the loopholes caused by manual input, but also to provide managers with various data of each product. We used bar code technology in the commodity inspection of air conditioners, and established a quality file for each product before leaving the factory, which effectively provided all kinds of information. ?
(4) Formulate rules and regulations for barcode management. The application of barcode must follow certain rules and conform to its scientificity. Establish the overall coding system, internal barcode generation rules, barcode printing system, barcode pasting specifications and barcode use system of products, and assess the barcode utilization rate of production workshops as economic and technical indicators.