Description and characteristics of two-dimensional bar code is a specific two-dimensional bar code geometry according to certain rules distribution of black and white graphic recording data symbol information in the code on the clever use of the preparation of the computer's internal logic constitute the basis of the "0", " 1 "bit stream concept, the use of a binary number that corresponds with the geometry to represent numerical information text through the image input device or optical scanning equipment automatically read in order to achieve automatic processing of information. It has some of barcode technology in common: Each symbology has its specific character set; each character occupies a certain width; has a certain parity functions. It also has information on different rows automatic recognition function, and handling characteristics graph rotation changes.
Apart from ordinary two-dimensional barcode has the advantages of one-dimensional barcodes, but also has information on large capacity, high reliability, confidentiality, security and strong, easy to make, and low cost. Precisely in order to meet this demand. Barcode ordinary one-dimensional bar code due to its incomparable superiority, it once appeared, by the majority of users of all ages. Their information capacity, high information density, coding ability, can be photos, text, fingerprints, palm prints, voice, signature information is encoded. Its easy printing, two-dimensional code error correction ability, decoding, high reliability, and has a strong anti-counterfeiting capabilities. It is precisely because the machine readable barcode and anti-counterfeiting can be achieved two important features that are ID card, driver's license, military card, voter card, social welfare card, passport, visa and other types of card ideal means of automatic identification.
Two-dimensional bar code features:
◆ information capacity
Depending on the ratio of air per square inch can accommodate from 250 to 1100 characters. Card valid in the area of international standards, and can accommodate 1848 alphabetic characters or 2729 numeric characters, about 500 characters of information. This two-dimensional bar code barcode information than ordinary high capacity several times.
◆ Wide range of coding
Can be photographs, fingerprints, palm prints, signature, voice, text, etc. Where the encoded digital information.
◆ confidentiality, security performance
With multiple security features, which can be password security, encryption software and use the information contained in such as fingerprints, photographs and other anti-counterfeiting, anti-counterfeiting security therefore has a very strong performance.
◆ decoding high reliability
Normal barcode decoding error rate of about two millionths, while the two-dimensional bar code error rate does not exceed one ten-millionth, decoding reliability.
◆ ability to correct errors
Using the world's most advanced mathematical correction theory, if the damaged area does not exceed 50% of the barcode as contamination, damage, etc. the lost information, you can decipher the missing information as usual.
◆ easy to make and low cost
Use of the existing lattice, laser, inkjet, thermal / thermal transfer, card machines and other printing technologies, you can on paper, card, PVC, or even two-dimensional bar code printed on the metal surface. Thus the additional cost is only the cost of ink, so people also known as two-dimensional bar code technology zero cost.
◆ Variable barcode symbol shape
The same amount of information, according to the shape of two-dimensional barcode vector art area and angle, etc., to the freedom of self-adjustment, and fully meet user needs. |
