Bar code (also called bar code) is a group of empty symbols arranged according to certain coding rules, which is used to represent information composed of certain characters, numbers and symbols. Bar code system is an automatic identification system composed of bar code symbol design, production and scanning reading.
Development history of bar code
Bar code first appeared in 1940s, but its practical application and development was around 1970s. Nowadays, 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, American Joe? Jo woodland and Bernie? Searwar, two engineers, began to study the use of codes to represent food items and corresponding automatic identification equipment, and obtained an American patent at 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. Unfortunately, the technology and commodity economy at that time could not print this code. But what about Joe after 10 years? As an engineer of IBM, Woodland became the founder of UPC code in North America. With Gillard? Several inventors, represented by Girard Fessel, applied for a patent in 1959, describing that each of the numbers 0-9 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？ Buninke (e? f？ B rinker) applied for another patent, which is to mark the bar code on the tram. A system invented by Searwar in 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. 197 2 monarch? Monarch Marking and others developed Code barcode, and American barcode technology entered a new development stage.
1973, UCC established UPC barcode system and 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, David of Inte rmec company? Alil (David? Dr Allair) developed code 39, which was quickly adopted by the US Department of Defense as a military bar code system. Code 39 was the first bar code combining letters and numbers, and was later widely used in industrial fields.
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 code, signed a memorandum of agreement on "European article coding", 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. (later changed to EAN international)
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; The ANSI standard MH 10.8M is used to interleave 25 codes, 39 codes and Kudba codes. At the same time, some industries have begun to establish industry standards to meet the needs of development. And after that, David? Alil developed code 49, which is a non-traditional bar code symbol with higher density than the previous bar code symbol (that is, the prototype of two-dimensional bar code). What about Ted? Ted Williams introduced 16K code, which is a code system suitable for laser scanning. By the end of 1990, * * had more than 40 bar code systems, and the corresponding automatic identification equipment and printing technology had 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. 1988 65438+On February 28th, with the approval of the State Council, the State Bureau of Technical Supervision established the "China Item Coding Center". The task of the center is to study and popularize bar code technology; Agree to organize, develop, coordinate and manage the barcode work in China.
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. Once these ties are connected with the E DI system, a multi-project and multi-factor information network is formed. The information related to various commodities is like being put into an invisible and never-ending automatic guidance and transmission mechanism, which flows to all parts of the world and is active in the world commodity circulation field.
Bar code overview
Bar code is a symbol that combines lines and spaces according to certain coding rules to represent certain letters, numbers and other data. During identification, a set of reflected optical signals is obtained by scanning with a bar code reader. After photoelectric conversion, this signal becomes a set of electronic signals corresponding to lines and spaces, which are decoded and restored to corresponding numbers, and then transmitted to the computer. Bar code recognition technology is quite mature, and its reading error rate is about one in a million, and the first reading rate is over 98%. It is an automatic data acquisition technology with high reliability, fast input, high precision, low cost and wide application.
There are more than 225 kinds of one-dimensional bar codes in the world, each of which has its own set of coding specifications, which stipulate that each letter (which may be text or numbers or numbers) consists of several bars and spaces, and the arrangement of letters. Generally, the popular one-dimensional bar codes are 39 code, EAN code, UPC code, 128 code, and ISBN and ISSN specially used for books and periodicals management.
The invention years of various one-dimensional bar codes are summarized in table 1. 1, and the standard formula year is summarized in the table 1. 2.
Table 1. 1 year of invention of one-dimensional bar code
The special significance of the inventor or company of the annual barcode name.
1949 bull's eye code n. Joe Woodland, Bernard Silver, the first barcode.
Bar code 1973UPCIBM's first large-scale application
1972 barcode marking system
197439 code David C. Allias (intermec) is the first commercial alphanumeric bar code.
1976 ean association
198 1 code 128
1983 code 93
Table 1.2 represents the year when the one-dimensional bar code standard was formulated.
Annual barcode inclusion standard
1982 code 39 military standard 1 189
1983 code 39, staggered 2/5, codabaransi MH10.8m.
1984UPCANSI MH 10.8M
1984 code 39AIAG standard
1984 coding 39HIBC standard
Since UPC, various barcode standards and specifications have been developed to meet different application requirements. Nowadays, barcode has become an indispensable basic condition for commercial automation. Barcodes can be divided into two categories: one-dimensional barcode (1D) and two-dimensional code (2D). At present, one-dimensional bar code is mainly used in commodities, so one-dimensional bar code is also called commodity bar code, and two-dimensional bar code is another bar code that attracts more and more attention. Its function is stronger than one-dimensional bar code and its application range is wider. Details will be introduced in the next chapter.
At present, there are about 225 kinds of one-dimensional bar codes in the world. This book only introduces the most common standards, such as UPC, EAN, code 39, code 128, etc. In addition, books and periodicals have internationally unified codes, especially ISBN (International Standard Book Number) and ISSN (International Standard Publication Number).
With the development of bar code technology and the diversification of three bar code systems, the standardization of bar code becomes more and more important. Therefore, the military standard 1 189 was formulated one after another. The ANSI standard MH 10.8M spans 25 yards, 39 yards and Coda bar codes. At the same time, some industries have begun to establish industry standards to meet the needs of development. Since then, David Ariel has developed another 49 yards. This is a non-traditional bar code symbol with higher density than the previous bar code symbol. Ted Williams)GFI988 introduces 16K code, which is similar to 49 code in structure. This is a relatively new coding system, which is suitable for laser systems. The link below gives a complete history (including what prompted people to invent bar codes)
Basics.ie/History, Reference: basics.ie/History,