What is a Barcode?
A barcode is a graphic identifier that arranges multiple black bars and spaces of varying widths according to certain coding rules to express a group of information. A common bar code is a pattern of parallel lines formed by black bars (short for short) and white bars (short for short) with very different reflectances. The bar code can indicate many information such as the country of manufacture, manufacturer, product name, production date, book classification number, mail start and stop location, category, date, etc. It is widely used [1] .
- A barcode is a set of multiple black bars and spaces of varying widths.
- In 1948, Bernard Selwo was also a graduate student at the Philadelphia Gas Institute of Technology. Once, he overheard the president of a local supermarket chain begging the dean to invent a way to automatically record merchandise sales at the checkout counter. The dean thought it was whimsical. But Selwo and his friend and graduate student, Joseph Woodland, were determined to try it out and believed it would make them rich [4]
- Recognition principle
- A bar code symbol is an information symbol combined by "bar" and "empty" with different reflectances according to certain coding rules. Because "bar" and "space" in the bar code symbol have different reflectivity to light, the bar code scanner receives reflected light signals of different strengths and weakly, and accordingly generates electric pulses with different potentials. The width of the "bar" and "empty" in the bar code symbol determines the length of the electrical pulse signal with different potential levels. The optical signal received by the scanner needs to be photoelectrically converted into an electrical signal and amplified by an amplifying circuit. Because the scanning spot has a certain size, edge ambiguity during barcode printing, and some other reasons, the electrical signal of the barcode amplified by the circuit is a smooth undulating signal, which is called an "analog electrical signal". The "analog electrical signal" needs to be shaped into the usual "digital signal". According to the coding rules corresponding to the coding system, the decoder can read and translate the "digital signal" into digital and character information [5]
- The commonly used codes in the world are EAN barcode, UPC barcode, 25 barcode, cross 25 barcode, Kurduba barcode, Code 39 barcode and Code 128 barcode, etc. [7]
- At present, bar code technology has been widely used in many fields, and the typical applications are the following five fields:
- First, retail . Retail is the most mature area for barcode applications. EAN product barcodes lay the foundation for the retail industry to apply barcodes for sales. At present, most of the products sold in supermarkets use EAN barcodes. When selling, scan EAN barcodes with a scanner. The POS system finds the corresponding names, prices, and other information from the database and statistics the products purchased by customers This greatly speeds up the speed and accuracy of the cash register. At the same time, various sales data can also be used as reference data for shopping malls and virtual merchants to purchase and supply. Because the sales information can be counted in time and accurately, the merchants can accurately grasp the circulation information of various commodities in the business process, which can greatly reduce the inventory and maximize the use of funds. Thus improving the efficiency and competitiveness of businesses [8]
- With the rapid expansion and development of retail and consumer markets, it has also promoted China
- There are three commonly used barcode reading devices: CCD scanner, laser scanner and light pen scanner.
- 1. CCD scanner
- The CCD scanner mainly uses a fixed light beam (usually a flood light source of light emitting diodes) to illuminate the entire barcode, reflects the barcode symbol onto the photosensitive element array, and recognizes the barcode symbol through photoelectric conversion. The new CCD scanner can recognize not only one-dimensional bar code and two-dimensional bar code, but also matrix two-dimensional bar code [10]
- Bar code is by far the most economical and practical automatic identification technology. Bar code technology has the following advantages.
- (1) Information collection is fast. Compared with keyboard input, bar code input is 5 times faster than keyboard input and enables real-time data input [11]
- A bar code is also called a bar code symbol. It is a parallel line graphic consisting of a set of regularly arranged bars, spaces, and characters, which is used to represent a certain information code. Common barcodes are composed of black bars (short for short) and white bars (short for short) with very different reflectances [12]
- The quality of the barcode design and printing quality is directly related to the success or failure of the barcode application. If the design does not meet the specifications, it may lead to the retirement of the entire printed matter and even affect the sales of the product. The following are some specifications and requirements for the design, production and printing of barcodes [13]
- (1) Standards for using barcodes. Standards for the use of bar codes include two aspects: one is the choice of bar code system; the other is the printing position and representation method of bar code symbols. The establishment of bar code standards is generally related to the specific habits and characteristics of a certain industry [14]
- Code tables around [17] :
| Prefix code | Country (or region) of the coding organization / application | Prefix code | Country (or region) of the coding organization / application |
|---|---|---|---|
| 000 019 030 039 060 139 | United States | 627 | Kuwait |
| 020 029 040 049 200 299 | Store code | 628 | Saudi Arabia |
| 050 059 | coupon | 629 | United arab emirates |
| 300 379 | France | 640 649 | Finland |
| 380 | Bulgaria | 690 699 | China |
| 383 | Slovenia | 700 709 | Norway |
| 385 | Croatia | 729 | Israel |
| 387 | BiH | 730 739 | Sweden |
| 389 | Montenegro | 740 | Guatemala |
| 400 440 | Germany | 741 | El Salvador |
| 450 459 490 499 | Japan | 742 | Honduras |
| 460 469 | Russia | 743 | Nicaragua |
| 470 | Kyrgyzstan | 744 | Costa Rica |
| 471 | Taiwan, China | 745 | Panama |
| 474 | Estonia | 746 | Dominica |
| 475 | Latvia | 750 | Mexico |
| 476 | Azerbaijan | 754 755 | Canada |
| 477 | Lithuania | 759 | Venezuela |
| 478 | Uzbekistan | 760 769 | Switzerland |
| 479 | Sri Lanka | 770 771 | Colombia |
| 480 | Philippines | 773 | Uruguay |
| 481 | Belarus | 775 | Peru |
| 482 | Ukraine | 777 | Bolivia |
| 484 | Moldova | 778 779 | Argentina |
| 485 | Armenia | 780 | Chile |
| 486 | Georgia | 784 | Paraguay |
| 487 | Kazakhstan | 786 | Ecuador |
| 488 | Tajikistan | 789 790 | Brazil |
| 489 | Hong Kong Special Administrative Region of China | 800 839 | Italy |
| 500 509 | United Kingdom | 840 849 | Spain |
| 520 521 | Greece | 850 | Cuba |
| 528 | Lebanon | 858 | Slovakia |
| 529 | Cyprus | 859 | Czech Republic |
| 530 | Albania | 860 | Yugoslavia |
| 531 | Macedonia | 865 | Mongolia |
| 535 | Malta | 867 | Korea |
| 539 | Ireland | 868 869 | Turkey |
| 540 549 | Belgium and Luxembourg | 870 879 | Netherlands |
| 560 | Portugal | 880 | Korea |
| 569 | Iceland | 884 | Cambodia |
| 570 579 | Denmark | 885 | Thailand |
| 590 | Poland | 888 | Singapore |
| 594 | Romania | 890 | India |
| 599 | Hungary | 893 | Vietnam |
| 600 601 | South Africa | 896 | Pakistan |
| 603 | Ghana | 899 | Indonesia |
| 604 | Senegal | 900 919 | Austria |
| 608 | Bahrain | 930 939 | Australia |
| 609 | Mauritius | 940 949 | new Zealand |
| 611 | Morocco | 950 | GS1 headquarters |
| 613 | Algeria | 951 | GS1 headquarters (product electronic code) |
| 615 | Nigeria | 960 969 | GS1 headquarters (shortened code) |
| 616 | Kenya | 955 | Malaysia |
| 618 | Ivory coast | 958 | Macau Special Administrative Region of China |
| 619 | Tunisia | 977 | Serials |
| 621 | Syria | 978 979 | books |
| 622 | Egypt | 980 | bill receivable |
| 624 | Libya | 981 983 | Ordinary coupon |
| 625 | Jordan | 990 999 | coupon |
| 626 | Iran |