Let me briefly talk about the concept of barcode. Barcode or barcode (barcode) is a graphic identification of multiple black bars and blanks of different widths arranged according to certain coding rules to express a set of information. symbol. A common barcode is a parallel line pattern composed of black bars (referred to as bars) and white bars (referred to as spaces) with very different reflectivities. Barcodes can indicate the country of production, manufacturer, product name, production date, book classification number, mail starting and ending location, category, date and many other information. Therefore, they are used in many fields such as commodity circulation, library management, postal management, and banking systems. Has been widely used. [1. The history of barcodes Barcode technology was first produced in the turbulent 1920s and was born in the laboratory of Westinghouse. An eccentric inventor named John Kermode "whimsically" wanted to automatically sort postal documents. At that time, every idea about the application of electronic technology was very novel. His idea was to mark envelopes with a barcode, where the information in the barcode would be the recipient's address, much like today's postal code. For this reason, Comand invented the earliest barcode identification. The design scheme is very simple (note: this method is called the module comparison method), that is, one "bar" represents the number "1", and two "bars" represent the number "2". ”, and so on. He then invented a barcode reading device consisting of basic components: a scanner (capable of emitting light and receiving reflected light); a method of measuring the reflected signal strips and voids, the edge positioning coil; and a device that uses the measurement results. method, the decoder. Comand's scanner used the then-new invention of photovoltaic cells to collect reflected light. The "empty" reflection is a strong signal, and the "bar" reflection is a weak signal. Unlike today's high-speed electronic component applications, Command uses magnetic coils to measure "bars" and "empties." It's like a child connecting a wire to a battery and wrapping it around a nail to clip paper. Commande used a coil with an iron core to attract a switch when it received a "empty" signal, and when it received a "bar" signal, it released the switch and connected the circuit. As a result, the earliest barcode readers were noisy. The switch is controlled by a series of relays, and "on" and "off" are determined by the number of "strips" printed on the envelope. With this method, barcode symbols sort letters directly. Shortly thereafter, Douglas Young, a collaborator of the Command Code, made some improvements based on the Command Code. The amount of information contained in the Command Code is quite low, and it is difficult to program more than ten different codes. The Yang code uses fewer bars, but takes advantage of the size variation of the spaces between the bars, just like today's UPC bar code symbology using four different bar space sizes. The new barcode symbology can encode a hundred different regions in the same size space, while the Comande code can only encode ten different regions. It was not until the patent documents of 1949 that the omnidirectional barcode symbol invented by Norm Woodland and Bernard Silver was recorded for the first time. There was no such record in the patent documents before that. There is no record of barcode technology being put into practical application. Norm Woodland and Bernard Silver's idea was to take Command and Young's vertical "bars" and "voids" and bend them into rings, much like an archery target. In this way, the scanner can decode the barcode symbol by scanning the center of the pattern, regardless of the direction of the barcode symbol. In the process of continually improving it using this patented technology, a science fiction writer, Isaac Azimov, wrote about using information encoding in his book The Naked Sun. Examples of new methods for automatic identification. At the time, people thought the barcode symbology in this book looked like a checkerboard with square tiles, but today's barcode professionals will immediately realize that it is a two-dimensional matrix barcode symbology. Although this barcode symbol has no orientation, positioning or timing, it is clear that it represents a high information density digital encoding. It was not until the development of the "QR code" by Iterface Mechanisms in 1970 that there were printing and reading equipment for two-dimensional matrix barcodes at a price suitable for sale. At that time, two-dimensional matrix barcodes were used to automate the typesetting process in newspapers. Two-dimensional matrix barcodes are printed on paper tape and scanned and read by today's one-dimensional CCD scanners. The light from the CCD shines on the paper tape, and each photocell is aimed at a different area of ??the paper tape. Each photocell outputs a different pattern depending on whether the barcode is printed on the paper tape, and the combination produces a high-density information pattern. In this way a single character can be printed in the same size space as a single bar in early Command codes. Timing information is also included, so the whole process is reasonable. When the first systems hit the market, the complete set of equipment, including printing and reading equipment, cost approximately $5,000. Soon thereafter, with the continuous development of LEDs (light-emitting diodes), microprocessors and laser diodes, there was an explosion of new identification symbols (symbolism) and their applications, which people called the "barcode industry." It is rare to find a company or individual today who has not been directly exposed to fast and accurate barcoding technology.

Since technological progress and development in this field are very rapid, and more and more application fields are being developed every day, it will not be long before barcodes are as popular as light bulbs and semiconductor radios, and will make every one of our lives All become easier and more convenient. [Edit this paragraph] 2. Barcode recognition principle To convert a barcode compiled according to certain rules into meaningful information, it requires two processes: scanning and decoding. The color of an object is determined by the type of reflected light. White objects can reflect visible light of various wavelengths, while black objects absorb visible light of various wavelengths. Therefore, when the light emitted by the barcode scanner light source is reflected on the barcode, the reflected light The light is illuminated on the photoelectric converter inside the barcode scanner, and the photoelectric converter converts the reflected light signals of different strengths into corresponding electrical signals. According to differences in principles, scanners can be divided into three types: light pen, CCD, and laser. The electrical signal is output to the amplifier circuit of the barcode scanner to enhance the signal, and then sent to the shaping circuit to convert the analog signal into a digital signal. The width of the white and black bars is different, and the duration of the corresponding electrical signal is also different. The decoder then determines the number of bars and spaces by measuring the number of 0,1 pulse digital electrical signals. The width of bars and spaces is determined by measuring the duration of the 0,1 signal. The data obtained at this time is still messy. To know the information contained in the barcode, you need to replace the barcode with the corresponding numbers and character information according to the corresponding encoding rules (for example: EAN-8 code). Finally, the details of the item are identified through data processing and management by a computer system. [Edit this paragraph] 3. Advantages of barcodes 1. High reliability. Barcode reading accuracy far exceeds manual recording, with an average of one error occurring every 15,000 characters. 2. High efficiency. Barcodes can be read very quickly, equivalent to 40 characters per second. 3. Low cost. Compared with other automated identification technologies, barcode technology only requires a small sticker and a relatively simple optical scanner, and the cost is quite low. 4. Easy to make. The writing of barcodes is very simple, and production only requires printing. It is called a "printable computer language". 5. Easy to operate. The barcode recognition equipment has a simple structure and is easy to use. 6. Flexible and practical. Barcode symbols can be entered manually on the keyboard, or they can be combined with relevant equipment to form an identification system to achieve automated identification, or they can be linked to other control equipment to achieve automated management of the entire system. [Edit this paragraph] 4. Scanning barcodes Scanning barcodes requires a scanner. The scanner uses its own light source to illuminate the barcode, and then uses a photoelectric converter to receive the reflected light and convert the light and dark of the reflected light into a digital signal. No matter what rule is used to print the barcode, it is composed of a quiet zone, a start character, a data character and a stop character. Some barcodes also have check characters between the data characters and the terminating character. ▲Quiet zone: As the name suggests, it is an area that does not carry any information and serves as a reminder. ▲Start character: The first character has a special structure. When the scanner reads this character, it begins to officially read the code. ▲Data characters: the main content of the barcode. ▲Check character: Verify whether the read data is correct. Different encoding rules may have different verification rules. ▲ Termination character: The last character also has a special structure and is used to inform that the code scanning is completed. It also plays the role of verification calculation. To facilitate bidirectional scanning, the start and end characters have an asymmetric structure. Therefore, the scanner can automatically rearrange the barcode information when scanning. There are three types of barcode scanners: light pen, CCD, and laser. The most primitive scanning method requires manually moving the light pen and making contact with the barcode. ▲CCD: A scanner that uses CCD as a photoelectric converter and LED as a light source. Within a certain range, automatic scanning can be achieved. And it can read barcodes on various materials and uneven surfaces, and the cost is relatively low. However, compared with the laser type, the scanning distance is shorter. ▲Laser: A scanner that uses laser as a light source. It can be divided into linear type, full angle type, etc. Line type: mostly used in handheld scanners, with long range and high accuracy. Full angle: Mostly horizontal, with a high degree of automation, and can automatically read barcodes in various directions. [Edit this paragraph] 5. Advantages of barcode technology Barcode is by far the most economical and practical automatic identification technology. Barcode technology has the following advantages: A. Fast input speed: Compared with keyboard input, barcode input is 5 times faster and can achieve "instant data input". B． High reliability: the error rate of keyboard input data is one in three hundred, the error rate of using optical character recognition technology is one in ten thousand, and the error rate of using bar code technology is less than one in a million. C. Large amount of information collected: Traditional one-dimensional barcodes can collect information of dozens of characters at a time, while two-dimensional barcodes can carry information of thousands of characters and have certain automatic error correction capabilities. D. Flexible and practical: Barcode identification can be used alone as a means of identification, or it can be formed into a system with related identification equipment to achieve automatic identification, and it can also be connected with other control equipment to achieve automated management. In addition, barcode labels are easy to produce and have no special requirements for equipment and materials. The identification equipment is easy to operate and does not require special training, and the equipment is relatively cheap. [Edit this paragraph] 6. The uniqueness of the coding rules of barcodes: the same product with the same specifications corresponds to the same product code, and the same product with different specifications corresponds to different product codes.

Different product codes are assigned according to the different properties of the product, such as weight, packaging, specifications, smell, color, shape, etc. Permanence: Once a product code is assigned, it cannot be changed and is lifelong. When such a product is no longer produced, its corresponding product code can only be put on hold and cannot be reused or allocated to other products. Meaningless: In order to ensure that the code has enough capacity to adapt to the needs of frequent product updates, it is best to use meaningless sequence codes. Barcode verification code formula: 1. First, number the barcode from right to left as "...4, 3, 2, 1." Starting from serial number two, add up the numbers in all even-numbered digits, and use Multiply the found sum by 3, then add all the odd-numbered numbers starting from number three, add the calculated sum to the sum of the even-numbered numbers multiplied by 3, and then get the sum. Then subtract this sum from the smallest multiple of 10 that is greater than this sum to get the check code. For example: this barcode is: 977167121601X (X is the check code). 1. 1+6+2+7+1+7=242, 24×3=723, 1+1+6+7+9=244, 72+24=965, 100-96=4, so the final correction Verification code X=4. The barcode is 9771671216014. [Edit this paragraph] 7. The difference between barcode coding systems UPC: (Unified Product Code) can only represent numbers. There are four versions of A, B, C, D, and E. Version A-12 digit version E-7 digit last digit The size of the check digit is 1.5" wide and 1" high, and the background must be clear. It is mainly used in the United States and Canada, and is used in industry, medicine, warehouses and other sectors. When UPC is decoded as twelve digits, the definition is as follows: first digit = numeric identification (already established by the UCC (Uniform Code Committee)). Digits 2-6 = manufacturer's identification number (including the first digit). 7-11=The 12th digit of the unique manufacturer product code=check digit (usedforerrordetection)Code3of9: can represent letters, numbers and other symbols ***43 characters: A-Z,0-9,-.$/+%, The length of the pace barcode is variable. Usually "*" is used as the starting and ending characters. The check code is not used. The code density is between 3-9.4 characters/inch. The blank area is 10 times the narrow bar. It is used in industry. , books, and ticket automated management. Code128: represents high-density data, the string is variable-length, and the symbol contains a check code. There are three different versions: A, B, and C. 128 characters can be used in the three string sets A, B, or C respectively. Industrial, warehouse, retail and wholesale. Interleaved2-of-5 (I2of5): can only represent numbers 0-9, variable length, continuous barcodes, all bars and spaces represent codes, the first number starts with a bar, and the second number consists of spaces. The blank area ratio The narrow strip is 10 times wider and is used in commodity wholesale, warehouses, airports, production/packaging identification, and industry. The barcode has a high reading rate and can be used for reliable scanning with fixed scanners. It has the highest density among all one-dimensional barcodes. Codabar (Cudabar code): can represent the numbers 0-9, the characters $, +, -, and the four characters a, b, cd which can only be used as start/terminator, variable length, no check Bit, used in material management, libraries, blood stations and current airport parcel delivery, the blank area is 10 wider than the narrow bar, non-continuous barcode, each character is represented as 4 bars and 3 spaces. Codabar is also known as NW7, NW7 is its name in Japan. PDF417 (QR code): A barcode composed of multiple lines. It does not need to be connected to a database. It can store a large amount of data. It is used in: hospitals, driver's licenses, material management, and cargo transportation. When the barcode is damaged to a certain extent, error correction can The barcode can correctly decode PDF417, a product developed by Symbol Technology Company in 1990. It is a multi-line, continuous, variable-length symbolic identifier that contains a large amount of data. Each barcode has 3-90 lines, and each line has a start part, data part, and end part. Its character set includes all 128 characters, and the maximum data content is 1850 characters. One-dimensional barcodes only express information in one direction (usually the horizontal direction), but do not express any information in the vertical direction. Their certain height is usually to facilitate the alignment of the reader. The application of one-dimensional barcodes can improve the speed of information entry and reduce the error rate, but one-dimensional barcodes also have some shortcomings: * Small data capacity: about 30 characters * Can only contain letters and numbers * Barcode size is relatively large (Low space utilization) *After a barcode is damaged, it cannot be read. A barcode that stores information in two-dimensional space in the horizontal and vertical directions is called a two-dimensional barcode (2-dimensional barcode). Like one-dimensional barcodes, there are many different encoding methods, or symbologies, for two-dimensional barcodes. In terms of the coding principles of these code systems, they can usually be divided into the following three types: 1. Linear stacked QR codes are produced by stacking multiple one-dimensional codes vertically based on the coding principles of one-dimensional barcodes. Typical code systems include: Code16K, Code49, PDF417, etc. 2. Matrix QR code is encoded in a rectangular space through the different distribution of black and white pixels in the matrix.

Typical code systems include: Aztec, MaxiCode, QRCode, DataMatrix, etc. 3. Postal codes are encoded through bars of different lengths, mainly used for mail encoding, such as: Postnet, BPO4-State. Among many types of 2D barcodes, commonly used code systems include: DataMatrix, MaxiCode, Aztec, QRCode, Vericode, PDF417, Ultracode, Code49, Code16K, etc. Among them: *DataMatrix is ??mainly used for marking small parts in the electronics industry, such as Intel This code is printed on the back of Intel's Pentium processor. *MaxiCode was developed by United Parcel Service (UPS) and is used for parcel sorting and tracking. *Aztec is launched by the American company WelchAllyn and can accommodate up to 3832 numbers or 3067 alphabetic characters or 1914 bytes of data. Below, we take the PDF417 code as an example to introduce the features and characteristics of the two-dimensional barcode. 1) Introduction to PDF417 The PDF417 code was invented by Dr. Wang Yinjing (sound), a Chinese student studying in the United States. PDF is the abbreviation of the three words PortableDataFile in English, which means "portable data file". Because each symbol character that makes up a barcode is composed of 4 bars and 4 spaces, if the narrowest bar or space that makes up the barcode is called a module, then the total number of modules of the above 4 bars and 4 spaces is one. It is set as 17, so it is called 417 code or PDF417 code. 2) Characteristics of PDF417 1. Large information capacity. In addition to expressing letters, numbers, and ASCII characters, PDF417 codes can also express binary numbers. In order to make the encoding more compact and increase the information density, PDF417 has three formats when encoding: * Extended alphanumeric compression format can accommodate 1850 characters; * Binary/ASCII format can accommodate 1108 bytes; * Numeric compression format can accommodate 2710 number. 2. Error correction capability One-dimensional barcodes usually have a verification function to prevent misreading. Once the barcode is defaced, it will be rejected. The two-dimensional barcode can not only prevent errors, but also correct them. Even if the barcode is partially damaged, the correct information can be restored. 3. The printing requirements are not high and can be printed with ordinary printing equipment, and faxes can also be read. 4. The PDF417 code can be read with a variety of reading devices. It can be read with a laser reader with raster, and an image reader with linear and area scanning. 5. The size is adjustable to adapt to different printing spaces. 6. The code system has been disclosed to form an international standard, and our country has also formulated the national standard of 417 codes. 3) The error correction function of PDF417 The error correction function of the two-dimensional barcode is achieved by repeatedly representing part of the information (redundancy). For example, in the PDF417 code, in addition to the information of this line, a certain line also contains information that reflects characters (error correction codes) in other positions. In this way, even if part of the barcode is damaged, its information can be restored through the error correction code that exists elsewhere. The error correction capability of PDF417 is divided into levels 0~8***9 depending on the number of error correction code words, as shown in Figure 4. The higher the level, the greater the number of correction code words, the stronger the correction ability, and the larger the barcode. When the correction level is 8, the barcode can be read correctly even if it is 50% stained. 4) Several deformations of PDF417 PDF417 also has several deformed coding forms: *PDF417 truncated code In a relatively "clean" environment, the possibility of barcode damage is very small, so the line indicator on the right can be omitted and Reduce terminators. *PDF code further reduced by PDF417 microcode. *Macro PDF417 code When the file content is too long and cannot be represented by one PDF417 code, it can be represented by a macro PDF417 code containing multiple (1~99999) barcode blocks. Advantages of two-dimensional barcodes From the above introduction, it can be seen that two-dimensional barcodes have obvious advantages compared with one-dimensional barcodes. In summary, they mainly include the following aspects: 1) larger data capacity; 2) transcending the limitations of alphanumeric characters 3) The barcode is relatively small in size 4) It is resistant to damage [edit this paragraph] 8. Production of barcodes Barcodes are generally produced by printing or printing barcodes through a barcode printer. The biggest difference between barcode printers and ordinary printers is that the printing of barcode printers is based on heat, using ribbons as printing media (or directly using thermal paper) to complete printing. With ribbons of different materials, high-quality printing can be achieved effects and enable continuous high-speed printing without supervision. 1. Application software LabelmxCorelDRAWPhotoshopIllustratorLabelmx is a professional barcode generation and printing software that integrates barcode generation, drawing design, label production, and batch printing. It can print fixed and variable data. CorelDRAW, Photoshop, and Illustrator are professional drawing design software. In addition, Labelmx Barcodes can be exported as vector images (.emf and .wmf) and used interactively with CorelDRAW, Photoshop, and Illustrator. [Edit this paragraph] 9. Product barcode: EAN-13 universal product barcode generally consists of a prefix part, manufacturer code, product code and check code.

The prefix code in the product barcode is a code used to identify the country or region. The coding authority is in the International Article Numbering Association, such as 00-09 representing the United States and Canada. 45-49 represents Japan. 690-692 represents mainland China, 471 represents Taiwan, and 489 represents Hong Kong SAR. The manufacturer's code is assigned to the article coding organization of each country or region. In my country, the manufacturer's code is assigned by the National Article Coding Center. Commodity codes are codes used to identify commodities. The right to assign codes is exercised by product manufacturers themselves. Manufacturers decide which Arabic numerals to use as product barcodes on their own products according to specified conditions. The product barcode finally uses a 1-digit check code to verify the correctness of the 1-12th digit code from the left in the product barcode. Product barcode refers to a symbol composed of a set of regularly arranged bars, spaces and corresponding characters, which is used to represent certain product information. The bars are dark and the spaces are dark, which are used for scanning and reading with barcode reading equipment. The corresponding characters consist of a set of Arabic numerals for people to read directly or input data into the computer through the keyboard. The information represented by this group of spaces and the corresponding characters is the same. Barcode technology was born with the development and application of computers and information technology. It is a new technology that integrates coding, printing, identification, data collection and processing. The use of barcode scanning is a major trend in market circulation in the future. In order to enable goods to circulate freely and widely around the world, companies must abide by the relevant regulations on product barcode management, whether designing and producing, applying for registration or using product barcodes. Currently, commonly used barcodes in the world include ENA barcode, UPC barcode, 25 barcode, crossed 25 barcode, Kudba barcode, 39 barcode and 128 barcode, etc. The most commonly used barcode on products is the EAN product barcode. The EAN commodity barcode, also known as the universal commodity barcode, was developed by the International Article Numbering Association and is commonly used around the world. It is currently the most widely used commodity barcode in the world. Our country is currently promoting the use of this kind of commodity barcode in the country. EAN product barcodes are divided into two types: EAN-13 (standard version) and EAN-8 (shortened version). The encoding of product barcodes follows the principle of uniqueness to ensure that product barcodes are not repeated worldwide, that is, one product item can only have one code, or one code can only identify one product item. Products of different specifications, different packaging, different varieties, different prices, and different colors can only use different product codes. The standard size of product barcodes is 37.29mmx26.26mm, and the magnification is 0.8-2.0. When the printing area allows, a barcode with a magnification of 1.0 or above should be selected to meet the reading requirements. The smaller the magnification of the barcode, the higher the printing accuracy requirement. When the printing accuracy cannot meet the requirements, it is easy to cause difficulty in reading the barcode. Since the reading of barcodes is achieved through the color contrast between the barcode bar and the space, in general, any color that can meet the contrast (PCS value) requirements can be used. Usually, light colors are used for hollows, such as white, orange, yellow, etc., and dark colors are used for strips, such as black, dark green, dark brown, etc. The best color combination is black bars and white space. According to practical experience in barcode detection, red, gold, and light yellow are not suitable colors for bars, and transparent and gold cannot be used as blank colors. EAN-8 product barcode refers to an 8-digit product barcode used for identification, which is composed of a 7-digit product item code and a 1-digit check character. The birth of commodity barcodes has greatly facilitated the circulation of commodities, and modern society is inseparable from commodity barcodes. According to statistics, currently 500,000 products in my country use internationally accepted commodity barcodes. After my country joins the WTO, enterprises will surely gain more space for activities on the international stage. In order to be in line with international practices and adapt to the needs of international economic and trade, enterprises cannot wait for product barcodes.

Prefix code encoding The country (or region) where the organization is located/Application field Prefix code encoding The country (or region) where the organization is located/Application field 000～019; 030～039; 060～139 United States 020～029; 040～049; 200～299 In-store Code 050～059 Coupon 300～379 France 380 Bulgaria 383 Slovenia 385 Croatia 387 Bosnia and Herzegovina 400～440 Germany 450～459; 490～499 Japan 460～469 Russia 470 Kyrgyzstan 471 Taiwan, China 474 Estonia 475 Latvia 476 Azerbaijan 477 Lithuania 478 Uzbekistan 479 Sri Lanka 480 Philippines 481 Belarus 482 Ukraine 484 Moldova 485 Armenia 486 Georgia 487 Kazakhstan 489 Hong Kong Special Administrative Region of China 500 ~ 509 United Kingdom 520 Greece 528 Lebanon 529 Cyprus 530 Albania 531 Macedonia 535 Malta 539 Ireland 540 ~ 549 Belgium and Luxembourg 560 Portugal 569 Iceland 570 ~ 579 Denmark 590 Poland 594 Romania 599 Hungary 600, 601 South Africa 603 Ghana 608 Bahrain 609 Mauritius 611 Morocco 613 Algeria 616 Kenya 618 Ivory Coast 619 Tunisia 621 Syria 622 Egypt 624 Libya 625 Jordan 626 Iran 627 Kuwait 628 Saudi Arabia 629 Arabia United Emirates 640～649 Finland 690～695 People's Republic of China 700～709 Norway 729 Israel 730～739 Sweden 740 Guatemala 741 El Salvador 742 Honduras 743 Nicaragua 744 Costa Rica 745 Panama 746 Dominica 750 Mexico 754～755 Canada 759 Venezuela 760～ 769 Switzerland 770 Colombia 773 Uruguay 775 Peru 777 Bolivia 779 Argentina 780 Chile 784 Paraguay 786 Ecuador 789～790 Brazil 800～839 Italy 840～849 Spain 850 Cuba 858 Slovakia 859 Czech Republic 860 Yugoslavia 865 Mongolia 867 North Korea 869 Turkey 870～879 Netherlands 880 South Korea 884 Cambodia 885 Thailand 888 Singapore 890 India 893 Vietnam 899 Indonesia 900 ~ 919 Austria 930 ~ 939 Australia 940 ~ 949 New Zealand 955 Malaysia 958 Macau Special Administrative Region of China 977 Serials 978, 979 Books 980 Notes receivable 981, 982 Ordinary circulation coupons 990 ~ 999 Coupon [Edit this paragraph] 10. Requirements for printing and making barcodes The standard size of product barcodes is 37.29mmx26.26mm, and the magnification is 0.8-2.0. When the printing area allows, a barcode with a magnification of 1.0 or above should be selected to meet the reading requirements. The smaller the magnification of the barcode, the higher the printing accuracy requirement. When the printing accuracy cannot meet the requirements, it is easy to cause difficulty in reading the barcode. Since the reading of barcodes is achieved through the color contrast between the barcode bar and the space, in general, any color that can meet the contrast (PCS value) requirements can be used. Usually, light colors are used for hollows, such as white, orange, yellow, etc., and dark colors are used for strips, such as black, dark green, dark brown, etc. The best color combination is black bars and white space. According to practical experience in barcode detection, red, gold, and light yellow are not suitable colors for bars, and transparent and gold cannot be used as blank colors. 11. The meaning of product barcode numbers. Take the barcode 6936983800013 as an example. This barcode is divided into 4 parts, from left to right: 1-3 digits: ***3 digits, corresponding to 693 of the barcode, which is the country code of China one. (690--695 are all Chinese codes, allocated internationally); 4-8 digits: ***5 digits, corresponding to 69838 of the barcode, representing the manufacturer code, applied by the manufacturer and allocated by the country; 9-12 Digits: ***4 digits, corresponding to 0001 of the barcode, representing the product code in the factory, which is determined by the manufacturer; Digit 13: ***1 digit, corresponding to 3 of the barcode, is a check code, based on a certain Algorithm, calculated from the previous 12 digits.