bar code
The concept of bar code
A bar code is a graphical identifier that expresses a set of information by arranging a number of black bars and blanks of varying widths in accordance with certain coding rules. A common barcode is a pattern of parallel lines made up of black bars (referred to as bars) and white bars (referred to as blanks) of widely varying reflectivity. The bar code can mark the country of production of the item, the manufacturer, the name of the commodity, the date of production, the book classification number, the place of origin and destination of the mail, the category, the date and many other information, and therefore in the distribution of goods, library management, postal management, banking system and many other fields have been widely used.
[Edit Paragraph]I. The history of the bar code
Barcode technology was first produced in the windy 1920s, born in the Westinghouse (Westinghouse) laboratory. An eccentric inventor named John Kermode had the "whimsical" idea of automating the sorting of postal documents, at a time when every idea for the use of electronics was a novelty.
His idea was to mark the envelope with a barcode, in which the information is the recipient's address, like today's postal code. To this end, Comande invented the earliest bar code marking, the design program is very simple (Note: This method is called the module comparison method), that is, a "bar" that the number "1", two "bar "that the number" 2 "and so on. Then, he invented a bar code reading device consisting of basic components: a scanner (able to emit light and receive reflected light); a method of determining the reflected signal bars and empty, i.e., edge positioning coils; and a method of using the results of the determination, i.e., the decoder.
Comande's scanner used a then-newly invented photocell to collect the reflected light. The "null" reflected back a strong signal, and the "bar" reflected back a weak signal. Unlike today's high speed electronic component applications, Comande utilized magnetic coils to determine the "bars" and "nulls". It was like a child connecting a wire to a battery and wrapping it around a nail to clip paper. Colemand used a coil with an iron core to attract a switch when receiving the "empty" signal, and when receiving the "bar" signal, release the switch and turn on the circuit. As a result, the earliest barcode readers were very noisy. The switches were controlled by a series of relays, and the "on" and "off" were determined by the number of "bars" printed on the envelope. In this way, the barcode symbols directly sorted the letters.
Shortly thereafter, Cormand's collaborator, Douglas Young, made some improvements to the Cormand code.
The Comande code contains a fairly low amount of information, and it is difficult to program more than ten different codes. The Young code uses fewer bars, but utilizes variations in the size of the spaces between the bars, just as today's UPC barcode symbology uses four different bar sizes. The new barcode symbology could encode one hundred different areas in the same size space, whereas the Comande code could only encode ten different areas.
The invention of the all-encompassing bar code symbology by Norm Woodland and Bernard Silver was first documented in the patent literature in 1949, and prior to that time there was no record of bar code technology in the patent literature and no precedent for putting it into practical use. The idea of Norm Woodland and Bernard Silver was to utilize the vertical "bars" and "blanks" of Comande and Young and bend them into a ring, much like an archery target. This way the scanner is able to decode the barcode symbol by scanning the center of the graphic, regardless of the orientation of the barcode symbol.
In the process of improving this patented technology, a science fiction writer, Isaac Azimov, described in his book The Naked Sun an example of using a new method of encoding information to achieve automatic identification. At the time, the bar code symbol in this book looked like a checkerboard, but today's bar code professionals immediately recognize it as a two-dimensional matrix bar code symbol. Although this bar code symbol has no direction, orientation, or timing, it clearly represents a high information density digital code.
It was not until 1970, when Iterface Mechanisms developed the "2D code," that there were affordable printing and reading devices for 2D matrix barcodes. At that time, 2D matrix barcodes were used to automate the typesetting process in newspapers. Two-dimensional matrix bar code printed on paper tape, by today's one-dimensional CCD scanner scanning and reading. CCD light emitted by the paper tape, each photocell aligned with a different area of the paper tape. Each photocell according to the paper with or without the printed barcode output different patterns, combining to produce a high-density information pattern. In this way, a single character can be printed on the same size space as a single bar in the early Comander code. Timing information was also included, so the whole process made sense. When the first system hits the market, a complete set, including printing and reading equipment, will cost about $5000.
Shortly thereafter, with the continued development of LEDs (light-emitting diodes), microprocessors, and laser diodes, there was a big explosion of new identifiers (symbology) and their applications, which came to be known as the "bar code industry". Today it is rare to find a company or individual who has not had direct contact with fast and accurate bar code technology. Because of the rapid technological advances and developments in this field, and because more and more applications are being developed every day, it won't be long before bar codes become as commonplace as light bulbs and semiconductor radios, and will make life easier and more convenient for each and every one of us.
[Edit Paragraph]Second, the recognition principle of the bar code
To compile the bar code in accordance with certain rules into meaningful information, need to go through the scanning and decoding two processes. The color of the object is determined by the type of its reflected light, white objects can reflect a variety of wavelengths of visible light, black objects absorb a variety of wavelengths of visible light, so when the bar code scanner light source issued by the light in the bar code after the reflection of the reflected light irradiated to the bar code scanner inside the photoelectric converter, the photoelectric converter according to the strength of the different reflective light signals, converted into the corresponding electrical signals. According to the principle of difference, the scanner can be divided into light pen, CCD, laser three. Electrical signal output to the barcode scanner amplifier circuit to enhance the signal, and then sent to the shaping circuit will be converted from analog to digital signals. The width of the white bar and the black bar are different, and the corresponding duration of the electrical signal is also different. Then the decoder by measuring the number of pulses of digital electrical signals 0, 1 to identify the number of bars and empty. By measuring the duration of the 0, 1 signal to determine the width of the bars and empty. At this point the data obtained is still disorganized, to know the information contained in the bar code, you need to be based on the corresponding coding rules (for example: EAN-8 code), the bar symbols into the corresponding digital, character information. Finally, data processing and management is performed by a computer system, and the detailed information of the item is recognized.
[edit]III. The superiority of barcode
1. Reliability. Barcode reading accuracy far exceeds the manual record, an average of 15,000 characters before an error.
2. High efficiency. Barcode reading speed is very fast, equivalent to 40 characters per second.
3. Low cost. Compared with other automated identification technology, bar code technology requires only a small sheet of stickers and relatively simple optical scanners, the cost is quite low.
4. Easy to produce. Barcodes are simple to write and require only printing, and are known as a "printable computer language".
5. Easy to operate. Barcode recognition equipment is simple and easy to use.
6. Flexible and practical. Barcode symbols can be manually entered into the keyboard, but also with the relevant equipment to form a recognition system to achieve automated recognition, but also with other control equipment to achieve the automated management of the entire system.
[Edit] Fourth, the scanning of the bar code
The scanning of the bar code needs a scanner, the scanner uses its own light source to irradiate the bar code, and then use the photoelectric converter to accept the reflected light, and the reflected light and darkness will be converted into digital signals. No matter what kind of rules are adopted to print the bar code, it consists of static area, start character, data character and end character. Some barcodes have a check character between the data character and the termination character.
▲Static area: as the name suggests, the area that does not carry any information, plays a role in prompting.
▲Start character: the first character, with a special structure, when the scanner reads the character, it will start to read the code formally.
▲Data character: the main content of the barcode.
▲Check character: check whether the read data is correct. Different code rules may have different checksum rules.
▲Termination character: the last character, the same with a special structure, used to inform the code scanning is complete, but also play a role in just checking the calculation.
In order to facilitate bi-directional scanning, the start and stop characters have an asymmetric structure. Therefore, the scanner can automatically rearrange the barcode information when scanning. Barcode scanner has a light pen, CCD, laser three
▲ light pen: the most primitive scanning method, you need to manually move the light pen, and also with the bar code contact.
▲CCD: CCD as a photoelectric converter, LED as a light-emitting light source scanner. Within a certain range, it can realize automatic scanning. And can read a variety of materials, uneven surfaces on the bar code, the cost is also relatively inexpensive. But compared with the laser type, the scanning distance is shorter.
▲Laser: laser as a light source scanner. It can be categorized into several types such as linear, full-angle, and so on.
Linear: Mostly used in handheld scanners, far range, high accuracy.
Full-angle: mostly horizontal, high degree of automation, in a variety of directions can automatically read the bar code.
[edit]V. Advantages of Barcode Technology
Barcode is by far the most economical and practical kind of automatic identification technology. Barcode technology has the following advantages
A. Input speed: compared with the keyboard input, barcode input speed is 5 times the keyboard input, and can realize the "instant data entry".
B. High reliability: keyboard input data error rate of one in three hundred, the use of optical character recognition technology error rate of one in ten thousand, and the use of bar code technology error rate of less than one million.
C. Collection of large amounts of information: the use of traditional one-dimensional bar code can collect dozens of characters at a time of information, two-dimensional bar code can carry thousands of characters of information, and has a certain degree of automatic error correction.
D. Flexible and practical: bar code marking can be used as a means of identification alone, but also with the identification of equipment and related to the formation of a system to achieve automated identification, but also with other control equipment linked to achieve automated management.
In addition, bar code labels are easy to produce, there is no special requirements for equipment and materials, recognition equipment is easy to operate, does not require special training, and equipment is also relatively inexpensive.
[edit]VI. Barcode coding rules
Uniqueness: the same specification of the same product corresponds to the same product code, the same product of different specifications should correspond to different product codes. According to the different nature of the product, such as: weight, packaging, specifications, smell, color, shape and so on, to give different commodity codes.
Permanence: Once the product code is assigned, it will not be changed, and it is for life. When this product is no longer produced, its corresponding product code can only be set aside, and can not be reused and reallocated to other goods.
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 sequential code.
Barcode check digit formula:
1, first of all, the barcode from right to left sequentially coded serial number "......4, 3, 2, 1." From the serial number two to all even number of serial number digit sum, multiply the sum by 3, and then from the serial number three to sum up all even number of serial number digit, multiply by 3, and then from the serial number three to sum up all even number of serial number digit. 3, then sum all the numbers on the odd-numbered ordinal positions starting with ordinal number three, add the product of the sum found and the sum of the numbers on the even-numbered ordinal positions just multiplied by 3, and arrive at the sum. Subtract this sum by the smallest multiple of 10 greater than the sum, and you get the checksum.
An example:
This barcode is: 977167121601X (X is the check digit).
1, 1+6+2+7+1+7=24
2, 24×3=72
3, 0+1+1+6+7+9=24
4, 72+24=96
5, 100-96=4
So the final check digit is X=4. The barcode is 9771671216014.
[edit]VII. barcode code system difference
UPC: (Uniform Product Code)
Can only indicate that there are four versions of the number A, B, C, D, E. Version A - 12-bit number Version E - 7-bit number The last bit of the check digit The size of the barcode is 1.5" wide by 1 " high and the background should be with a clear Mainly used in the United States and Canada. Used in the United States and Canada for industrial, pharmaceutical, warehouse and other sectors. When the UPC is decoded as twelve bits, the definitions are as follows: 1st bit = numeric identifier (already established by the UCC (Uniform Code Council). Bits 2-6 = Manufacturer's identification number (including the first bit) Bits 7-11 = Unique manufacturer's product code Bit 12 = Checksum bit (used for error detection)
Code 3 of 9 :
43 characters that can represent letters, numbers, and a few other symbols***: A -Z,0 - 9,-. $/+%,pace The length of the barcode is variable, usually using the "*" sign as the start and stop check digits without code density between 3 - 9.4 characters per inch, and the blank area is 10 times as narrow as the barcode, which is used in industry, books, and automated management of tickets.
Code 128:
Indicates high density data, variable string length, check digits in symbols, three different versions: A, B, and C. Available in 128 characters in a set of three strings A, B, or C. Used in industry, warehouses, retail, and wholesale.
Interleaved 2-of-5 (I2 of 5):
Can only represent digits 0 -9 Variable length, continuous barcode, all bars and blanks represent the code, the first digit starts with a bar, the second digit consists of a blank The blank area is 10 times wider than the narrow bar, used in wholesale, warehouses, airports, production/packaging identification, industry. The barcode has a high read rate, can be reliably scanned by fixed scanners, and has the highest density of all 1D barcodes.
Codabar:
Can represent numbers 0 - 9, characters $, +, -, and four characters a, b, c d that can only be used as a start/stop character, variable length, no check digits, used in materials management, libraries, blood stations, and current airport parcel deliveries, whitespace is 10 wide compared to the narrow bar, non-contiguous barcodes with 4 bars and 3 blanks per character. for 4 bars and 3 blanks per character. Codabar aka NW 7,NW 7 is called in Japan.
PDF417 (two-dimensional code):
The barcode is composed of multiple lines, does not need to be connected to a database, itself can store a large amount of data, used in: hospitals, driver's licenses, material management, transportation of goods, when the barcode is subjected to a certain degree of damage, the error correction can be made so that the barcode can be correctly decoded PDF417, is the XunBoer (Symbol) Technology Corporation in 1990 developed products. In 1990, Symbol Technologies Inc. developed the product. It is a multi-line, continuous, variable-length symbol mark containing a large amount of data. Each barcode has 3 - 90 lines, each line has a start section, data section, end section. Its character set includes all 128 characters and the maximum data content is 1850 characters.
A 1D barcode expresses information only in one direction (usually horizontally), while in the vertical direction it does not express any information, and its certain height is usually for easy reader alignment.
The use of 1D barcodes can increase the speed of information entry and reduce the error rate, but there are some shortcomings of 1D barcodes:
* Data capacity is small: about 30 characters
* Can only contain letters and numbers
* The size of the barcode is relatively large (low space utilization)
* The barcode can not be read when damaged
* Barcodes can not be read when damaged
* The barcode is damaged. They cannot be read when damaged
A bar code that stores information in two dimensions, horizontally and vertically, is called a 2-dimensional bar code.
Like one-dimensional bar codes, two-dimensional bar codes have many different encoding methods, or code systems. In terms of the coding principles of these code systems, they can be usually categorized into the following three types
1. Linear stacked 2-dimensional bar code
It is based on the coding principles of 1-dimensional bar code, and multiple 1-dimensional codes are stacked vertically and produced. Typical code systems such as: Code 16K, Code 49, PDF417 and so on.
2. Matrix 2D Code
It is encoded in a rectangular space by the different distribution of black and white pixels in the matrix. Typical code systems are Aztec, Maxi Code, QR Code, Data Matrix, etc.
3.
3. Postal Code
Encoded by bars of different lengths, mainly used for mail encoding, e.g. Postnet, BPO 4-State.
Among the many kinds of 2D barcodes, the commonly used code systems are Data Matrix, Maxi Code, Aztec, QR Code, Vericode , PDF417, Ultracode, Code 49, Code 16K, etc. Among them:
* Data Matrix is mainly used in the electronics industry for the identification of small parts, such as Intel's (Intel) Pentium processor on the back of the printing of this code.
* Maxi Code is developed by the United Parcel Service (UPS) for parcel sorting and tracking.
* Aztec was introduced by Welch Allyn (USA) and can hold up to 3832 numbers or 3067 alphabetic characters or 1914 bytes of data.
Below, we take PDF417 code as an example to introduce the characteristics and features of 2D barcode.
I) PDF417 Introduction
PDF417 code is invented by Dr. Yinjing Wang, a Chinese American, PDF is the acronym of the first letter of the three words of the English Portable Data File, which means "portable data file". Because of the composition of the bar code of each symbol character is composed of four bars and four empty composition, if the composition of the bar code of the narrowest bar or empty called a module, the above four bars and four empty the total number of modules must be 17, so called 417 code or PDF417 code.
(ii) PDF417 features
1. large information capacity
PDF417 code in addition to letters, numbers, ASCII characters can be expressed in addition to binary numbers. In order to make the code more compact and increase the information density, PDF417 is encoded in three formats:
* Extended Alphanumeric Compression Format Holds 1850 characters;
* Binary / ASCII Format Holds 1108 bytes;
* Numeric Compression Format Holds 2710 digits.
2. Error Correction Capabilities
One-dimensional barcodes typically have checksums to prevent misreading, and will be rejected if the barcode is defaced. The two-dimensional bar code not only prevents errors, but also corrects errors, even if the bar code is partially damaged, the correct information can be restored.
3. Printing requirements are not high
Ordinary printing equipment can be printed, and faxes can be read.
4. Can be read by a variety of reading devices
PDF417 code can be used with a raster laser reader, linear and surface scanning image reader to read.
5. Adjustable size to adapt to different print space
6. Code open has formed an international standard, China has also developed a 417 code of the national standard.
(C) PDF417 error correction
The error correction function of the 2D barcode is realized by repeating part of the information (redundancy). For example, in the PDF417 code, a line in addition to the information contained in this line, there are a number of reflecting the characters in other positions (error correction code) of the information. In this way, even when a part of the bar code is damaged, but also through the existence of other positions in the error correction code to restore its information.
PDF417 error correction capability according to the number of words of the error correction code is divided into 0 ~ 8***9 level, see Figure 4, the higher the level, the more words of the correction code, the stronger the corrective ability, the larger the bar code. When the correction level is 8, even if the bar code is 50% defaced can be read correctly.
(D) PDF417 several kinds of deformation
PDF417 there are several kinds of deformation of the code form:
* PDF417 truncated code
In a relatively "clean" environment, the bar code damage is very small, the right line indicator can be omitted and reduce the terminator. reduce the terminator.
* PDF417 microcode
A further reduced PDF code.
* Macro PDF417 Code
When a document is too long to be represented by a single PDF417 code, it can be represented by a macro PDF417 code containing multiple (1 to 999999) barcode chunks.
Advantages of 2D barcodes
From the above introduction, it can be seen that, compared with one-dimensional barcode 2D barcode has obvious advantages, summarized in the following aspects:
(a) data capacity is greater
(b) beyond the limitations of the alphanumeric
(c) the barcode relative to the size of the small
(d) has a resistance to damage
[edit]VIII, the production of bar codes
The production of bar codes is generally used to print or print bar codes through bar code printers. The biggest difference between barcode printers and ordinary printers is that barcode printers print on a thermal basis, with the ribbon as the print medium (or directly using thermal paper) to complete the print, with different materials of the ribbon to achieve high-quality printing results and in the case of unattended to achieve continuous high-speed printing.
I. Application Software
Label mx
CorelDRAW
Photoshop
Illustrator
Label mx belongs to the professional barcode generator and printing software, which is integrated with barcode generator, graphic designer, label maker, and batch printing. Print fixed and variable data, CorelDRAW, Photoshop, Illustrator is a professional graphic design software, in addition, Label mx can export the barcode as a vector image (.emf and .wmf) and CorelDRAW, Photoshop, Illustrator interactive use.
[Edit]IX. Commodity barcode:
EAN-13 general merchandise barcode generally consists of a prefix part, the manufacturer's code, the commodity code and check digit. Commodity bar code prefix code is used to identify the country or region of the code, the right to assign the code in the International Article Numbering Association, such as 00-09 on behalf of the United States, Canada. 45-49 on behalf of Japan. 690-692 on behalf of mainland China, 471 on behalf of China's Taiwan, 489 on behalf of the Hong Kong SAR. Manufacturer code is empowered in each country or region of the article code organization, China by the National Article Coding Center to give the manufacturer code. Commodity code is used to identify the code of the commodity, the right to assign the code is exercised by the product manufacturer itself, the manufacturer in accordance with the conditions of the provisions of their own decision on what kind of goods in their own use of which Arabic numerals for the commodity bar code. Commodity bar code with a check digit to verify the correctness of the commodity bar code in the left from the first l-12 digital code.
Commodity bar code refers to a set of rules arranged by the bar, empty and its corresponding characters composed of signs, to indicate a certain commodity information symbols. One of the bar for the dark, empty for the Na color, for bar code reading equipment scanning and reading. Its corresponding characters by a set of Arabic numerals, for people to read directly or through the keyboard to the computer to enter data to use. This set of empty bars and the corresponding characters represent the same information.
Barcode technology is born with the development and application of computer and information technology, which is a new technology that integrates coding, printing, identification, data acquisition and processing.
The use of barcode scanning is a major trend in future market circulation. In order to make the goods can be in the world free and extensive circulation, the enterprise whether design and production, application for registration or use of commodity bar code, must follow the relevant provisions of the commodity bar code management.
At present, the world's commonly used code system has ENA barcode, UPC barcode, two-five barcode, cross two-five barcode, Kudumba barcode, three-nine barcode and 128 barcode, etc., and commodities on the most commonly used is the EAN commodity barcode.
The EAN commodity bar code, also known as the Universal Commodity Bar Code, was developed by the International Article Numbering Association (IANA) and is commonly used around the world, and is one of the most widely used commodity bar codes in the world at present. It is the most widely used commodity barcode in the world, and is currently used in China. EAN commodity barcodes are divided into two types: EAN-13 (standard version) and EAN-8 (shortened version).
The code of the commodity bar code follows the principle of uniqueness to ensure that the commodity bar code is not repeated throughout the world, that is, a commodity item can only have a code, or a code can only identify a commodity item. Different specifications, different packaging, different varieties, different prices, different colors of goods can only use different commodity code.
The standard size of the commodity bar code is 37.29mm x 26.26mm, magnification is 0.8-2.0. When the printing area allows, should choose 1.0 times the bar code to meet the literacy requirements. The smaller the magnification of the bar code, the higher the printing accuracy requirements, when the printing accuracy can not meet the requirements, easy to cause bar code reading difficulties.
As the barcode reading is achieved through the barcode bar and empty color contrast, in general, as long as the contrast (PCS value) to meet the requirements of the color can be used. Usually light colors are used for the empty color, such as white, orange, yellow, etc., and dark colors are used for the bar color, such as black, dark green, dark brown, etc. The best color combination is black bar, white bar, dark brown bar. The best color combination is black and white. According to the practical experience of barcode detection, red, gold, light yellow should not be used as the color of the bar, transparent, gold can not be used as the color of the empty.
EAN-8 commodity bar code refers to the identification of the digital code for the 8-bit commodity bar code, by the 7-bit numerical representation of the commodity item code and 1-bit numerical representation of the check digit composition.
The birth of the commodity bar code greatly facilitates the flow of goods, modern society has been inseparable from the commodity bar code. According to statistics, China has 500,000 kinds of products using the internationally recognized commodity bar code. After China's accession to the WTO, enterprises in the international arena will win more space for activities. To be in line with international practice, to adapt to the needs of international trade and commerce, enterprises can not wait for the commodity bar code.
Prefix code The country ( or region ) of the coding organization / application area Prefix code The country ( or region ) of the coding organization / application area
000 ～ 019; 030 ～ 039; 060 ～ 139 U.S.A.
020 ～ 029; 040 ～ 049; 200 ～ 299 In-store code
050 ～ 059 Coupons
300 to 379 France
380 Bulgaria
383 Slovenia
385 Croatia
387 Bosnia and Herzegovina
400 to 440 Germany
450 to 459;490 to 499 Japan
460 to 469 Russia
470 Kyrgyzstan
471 Taiwan
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 to 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
629 United Arab Emirates
640 to 649 Finland
690 to 699 People's Republic of China
700 to 709 Norway
729 Israel
730 to 739 Sweden
740 Guatemala
741 El Salvador
741 El Salvador
742 Honduras
743 Nicaragua
744 Costa Rica
745 Panama
746 Dominican Republic
750 Mexico
754 to 755 Canada
759 Venezuela
760 to 769 Switzerland
770 Colombia
773 Uruguay
775 Peru
777 Bolivia
779 Argentina
780 Chile
784 Paraguay
786 Ecuador
789 to 790 Brazil
800 to 839 Italy
840 to 849 Spain
850 Cuba
858 Slovakia
859 Czech Republic
860 Yugoslavia
865 Mongolia
867 North Korea
869 Turkey
870 to 879 Netherlands
880 South Korea
884 Cambodia
885 Thailand
888 Singapore
890 India
893 Vietnam
899 Indonesia
900 to 919 Austria
930 to 939 Australia
940 ～ 949 New Zealand
955 Malaysia
958 Macao Special Administrative Region of China
977 Serial Publications
978, 979 Books
980 Bills Receivable
981, 982 Ordinary Circulation Coupons
990 ～ 999 coupons
[Edit]Ten, printing and production of bar code requirements
The standard size of the commodity bar code is 37.29mm x 26.26mm, magnification is 0.8-2.0. When the printing area allows, should choose 1.0 magnification of the bar code, in order to meet the literacy requirements. The smaller the magnification of the bar code, the higher the printing accuracy requirements, when the printing accuracy can not meet the requirements, easy to cause bar code reading difficulties.
As the barcode reading is achieved through the barcode bar and empty color contrast, in general, as long as the contrast (PCS value) to meet the requirements of the color can be used. Usually light colors are used for the empty color, such as white, orange, yellow, etc., and dark colors are used for the bar color, such as black, dark green, dark brown, etc. The best color combination is black bar, white bar, dark brown bar. The best color combination is black and white. According to the practical experience of barcode detection, red, gold, light yellow should not be used as the color of the bar, transparent, gold can not be used as the color of the empty.
Eleven, the meaning of the commodity bar code numbers
Take the bar code 6936983800013 as an example
This bar code is divided into four parts, from left to right, respectively:
1-3: ***3, corresponding to the bar code 693, is one of China's country code. (690--695 are all Chinese codes, assigned internationally);
Bits 4-8: ***5 bits, corresponding to 69838 of this barcode, represent the manufacturer's code, which is applied for by the manufacturer and assigned by the state;
Bits 9-12: ***4 bits, corresponding to 0001 of this barcode, represent the in-plant commodity code, which is determined by the manufacturer itself;