1, according to the classification code system

1) UPC codes

In 1973, the United States took the lead in the domestic commercial system applied in the UPC codes after Canada also USES the UPC codes in the business system. UPC code is a fixed length of continuous digital code system, the character set for the Numbers 0 to 9. It USES the width of the four elements, each article or empty is 1, 2, 3 or 4 times the unit element width. IPC code has two types, namely UPC - A code and UPC - E code.

2) the EAN code

In 1977, the European economic community countries in accordance with the standards of UPC codes developed European item code EAN code, compatible with UPC codes, and both have the same system of symbols. EAN code structure and UPC codes are the same number of characters, and fixed length, continuous digital code system, its character set is 0 ~ 9. It USES the width of the four elements, each article or empty is 1, 2, 3 or 4 times the unit element width. EAN code has two types, namely EAN 13 yards and EAN - 8 yards.

3) cross 25 yards

Cross 25 yards is a variable length of continuous self checking system of digital code, the character set for the Numbers 0 to 9. In two widths, each article and empty is wide or narrow element. Coded character number is even, all the data on the odd position with bar code, even the data on the location with empty coding. If is an odd number of data encoding, then fill in the data before a 0, in order to make for an even number of digital data.

4) a 39

39 is the first letter of digital code system. By Intermec company launched in 1974. It's length than discrete self-calibration risks alphanumeric code system. The character set for the number 0-9, 26 a capital letter and 7 special characters (-,., Space, /, %, $), a total of 43 characters. Each character consists of nine elements, including five article (article 2 wide and narrow 3) and 4 empty (a wide empty, three narrow empty), is a kind of discrete yards.

5) library, the code

Kurdish and Code (Code Bar) appeared in 1972, is a variable length of continuous self checking system of the digital Code. The character set for the number 0-9 and 6 special characters (-, :, /,., +, RMB), a total of 16 characters. Often used in warehouse, blood Banks and air express parcel.

6) 128 yards

128 yards appeared in 1981, is a variable length of continuous self checking system of the digital code. It USES the width of the four elements, each character consists of three and three empty, a total of 11 elements of unit width, also called (11, 3) code. It by 106, with the bar code characters, bar code characters have three different meanings of each character set, A, B, C respectively. It USES the three alternate character set can be 128 ASCII encoding.

7) 93 yards

93 yards is a variable length of continuous alphanumeric code system. The character set to become digital. 0-9, 26 a capital letter and seven special characters (-,., Space, /, +, %, $) and four control characters. Each character consists of three and three Abraham, a total of nine element width.

8) 49 code

49 code is a multi-line type, length, continuously variable alphanumeric code system. Appeared in 1987, is mainly used for small items of symbols on the label. Use a variety of widths. The character set for the number 0-9, 26 a capital letter and seven special characters (-,., /, +, Space, %, %, $), three function keys, tuo, F3 (F1) and three transformation characters, a total of 49 characters.

9) other code system

Apart from the above code, there will be other code system, such as 25 yards appeared in 1977, is mainly used for electronic tag; Deformation of the matrix of 25 yards is 11 yards; Nixdorf code has been replaced, Plessey EAN code code appears in May 1971 is mainly used in the library, etc.

2, according to the dimension of classification

1) ordinary one-dimensional bar code

Ordinary one-dimensional bar code, since the advent of quickly get popular and widely used. But because of one dimension barcode information capacity is small, such as commodity barcodes can only 13 of the Arabic numerals, more information on the description of the goods can only rely on the support of the database, left the database is established beforehand, the barcode becomes a madrassa reflected, non-existent, and bar code application scope is limited to a certain.

2) two dimensional barcode

Except possesses the advantages of ordinary barcode, two dimensional barcode also has a large capacity of information, high reliability, strong confidentiality rubber seals, easy to manufacture, low cost advantages.

American Symbol company officially launched in 1991, called PDF417 two-dimensional bar code, referred to as PDF417 bar code, namely \"portable data file\". FDF417 bar code is a kind of high density, high information content of the portable data file, is the realization of card and card, etc. Large capacity, high reliability information automatic storage, carrying and use of the machine automatically recognized ideal means.

3) dimensional barcode

Since the 1980 s, the people around how to improve the information density of bar code symbol, has carried on the research work. Dimensional bar code and container barcode become the direction of research, to show and application.

Information density is an important parameter of bar code symbol, according to the number per unit length may be written in letters, often described as: the number of letters/cm. The main factors influencing the information density is a, empty structure and narrow the width of the component system.

128 yards and 93 yards is people to improve the density of failed attempts. 128 yards to the city in 1981 is recommended; 93 yards and put into use in 1982. These two kinds of code symbols of the density were nearly 30% higher than a 39.

With the development of bar code technology and barcode SanZhi continue to increase, the kinds of barcode standardization is becoming more and more important. To this end, has formulated the military standard 1189; Cross 25 yards, 39 and Coda Bar code ANSI standard MH10.8 M, etc. At the same time, some industries are beginning to establish industry standards, to meet the needs of the development. Since then, David. Ah, and developed the 49 yards. This is a kind of unconventional bar code symbol, it barcode symbol has a higher density than ever before. Ted Williams (Ted Williams) GFI988 launched 16 k code, the code structure is similar to the 49 code, is a relatively new type of code, suitable for laser system.