QR(Quick Response) code, also known as two-dimensional bar code, is a black-and-white figure with specific geometry and distributed on the plane (two-dimensional direction) according to certain rules, and it is a key for all information and data. In modern business activities, it can be widely used, such as product anti-counterfeiting/traceability, advertisement push, website link, data download, commodity trading, positioning/navigation, electronic certificate, vehicle management, information transmission, business card exchange, wifi*** enjoyment and so on. Initially, food and corresponding automatic identification equipment were represented by codes. Bar code first appeared in 1940s, but its application and development was around 1970s. At present, bar code technology has been widely used in all countries and regions of the world, and is rapidly spreading to all parts of the world. The application fields are more and more extensive and gradually penetrate into many technical fields. As early as the 1940s, two engineers, jo woodland and Berny Searwar, began to study how to use codes and corresponding automatic identification devices to represent food items, and obtained American patents in 1949. This mode is very similar to a miniature archery target, which is called "bull's-eye" code. The concentric circles of the target are drawn into rings by circles and spaces. In principle, the "bull's-eye" code is very similar to the later bar code, but unfortunately, the technology and commodity economy at that time could not print this code. However, 20 years later, jo woodland became the founder of UPC code as an engineer of IBM. Several inventors, represented by Girard Fe- -ssel, applied for a patent in 1959, describing that every number from 0 to 9 can be composed of seven parallel bars. But this code makes the machine difficult to read, and it is not convenient for people to read. However, this idea did promote the emergence and development of bar codes later. Soon, E·F· brinker applied for another patent, which was to mark the bar code on the tram. The system invented by Searwar in the late 1960s was adopted by the North American railway system. These two items can be said to be the earliest application of bar code technology. 1970, the United States supermarket ad hoc committee formulated UPC code, and many organizations also put forward various bar code symbol schemes, as shown in the lower right and left figure above. UPC code was first tried in the grocery retail industry, which laid the foundation for the unification and wide adoption of bar codes in the future. The following year, Blesi Company developed the Blesi code and the corresponding automatic identification system for inventory inspection. This is the first practical application of barcode technology in warehouse management system. 1972, monarch mark and others developed code bar code, and American bar code technology entered a new development stage. From 65438 to 0973, the Unified Coding Association of America (UCC) established UPC barcode system, which standardized the code system. In the same year, the grocery industry adopted UPC code as a general standard coding system, which played a positive role in promoting the wide application of bar code technology in commercial circulation and sales. 1974, Dr. Davide Allair of Intermec Company developed code 39, which was quickly adopted by the US Department of Defense as a military bar code system. Code 39 is the first alphanumeric bar code, which was later widely used in the industrial field. From 65438 to 0976, the successful application of UPC code in American and Canadian supermarkets greatly inspired people, especially Europeans. The following year, EuropEAN * * * entities formulated European article codes ean- 13 and EAN-8 on the basis of UPC-A codes, signed a memorandum of agreement on "European article codes", and formally established the European article coding association (ean). 198 1 year, because EAN has developed into an international organization and changed its name to "ean international" for short. However, due to historical reasons and habits, it is still called EAN. Japan established POS system from 1974, and studied standardization, information input mode and printing technology. On the basis of EAN, 1978 compiled the Japanese commodity code Jan. In the same year, he joined EAN International, began to register manufacturers, and devoted himself to the development of barcode technology and its series products, becoming the largest user of EAN after 10 years. Since the early 1980s, many researches have been done to improve the information density of bar code symbols. 128 code and 93 code are research results. 198 1 recommended code 128, 1982 use code 93. The advantage of these two codes is that the symbol density of bar code is nearly 30% higher than that of code 39. With the development of bar code technology, there are more and more kinds of bar code systems, and the standardization problem is very prominent. Therefore, the military standard1189 was formulated successively; 25-yard, 39-yard and Kudba-yard, which span the ANSI standard MH 10.8M, etc. At the same time, some industries have begun to establish industry standards to meet the needs of development. Since then, David Alil has developed code 49, which is an unconventional bar code symbol with higher density than previous bar code symbols. Then Ted Williams introduced 16K code, which is a code system suitable for laser systems. Up to now, * * * has more than 40 bar code systems, and the corresponding automatic identification equipment and printing technology have also made great progress. Since the mid-1980s, some universities, scientific research departments and some export enterprises in China have gradually put the research, popularization and application of barcode technology on the agenda. Some industries, such as books, posts and telecommunications, materials management departments and foreign trade departments, have begun to use barcode technology. With the advent of the information society with economic globalization, information networking, internationalization of life and localization of culture, bar code and bar code technology, which originated in the 1940s, were studied in the 1960s, applied in the 1970s and popularized in the 1980s, have caused great changes in the world circulation field. As a printable computer language, barcode is called "computer culture" by futurists. In the field of international circulation in the 1990s, bar code was hailed as the "ID card" for goods to enter the international computer market, which made the whole world sit up and take notice. Bar codes printed on commodity packaging, like economic information ties, organically link manufacturers, exporters, wholesalers, retailers and customers all over the world. These ties, once connected with EDI system, form a multi-project and multi-factor information network, and the related information of various commodities is like being put into an invisible and never-ending automatic guiding transmission mechanism, which flows to all parts of the world and is active in the world commodity circulation field.