The barcode card is a barcode recording information composed of a set of rules, empty and its corresponding characters, and the common barcode symbols are printed by black bars and white space, when the light is on the bar code symbol, the black bars and the white space produce a strong contrast, so that the different reflectivity of the light and the strip can be used to read the information.
The barcode card is divided into one-dimensional code and QR code. One-dimensional code is more commonly used, such as the barcode on the packaging of daily goods is one dimensional code. Its information storage is small, can only store a code, and use the code to access the data in the computer network. QR code is developed in recent years, it can store more information in a limited space, including text, image, fingerprint, signature, etc, and can be separated from the computer.
Barcode card making is simple, ordinary barcode can be printed or copied according to certain requirements, the cost is low, but its reading equipment ( especially the QR code reading equipment ) ) It's more expensive.Different from the magnetic card and IC card, the information in the barcode card can not be rewritten, and the security performance is poor and the standard is not unified, which limits its application. The information that the barcode loads is the number, the letter, these numbers, the letter is passes according to certain standard code number string. Barcode coding technology mainly involves barcode coding rules and standards. The code rule of barcode is the main basis for making code standard and identifying barcode symbol.
At present, there are several commonly used codes in the world :
DUPC code 1973, the United States takes the lead in domestic commercial system application. The code is mainly used in commercial systems. The length of the code is fixed to 12 bits.
EAN Code In 1977, the European Economic Community countries formulated EAN codes for European articles in accordance with the UPC standard. There are two types of EAN codes :
EAN13 and EAN-8. The Interleaveed 2 of 5Code is a variable length continuous self-checking digital code system.
39 yards ( Code 3 of 9 ) is a variable length discrete self-checking code-like code system. The coda bar code is a discrete self-checking digital code system with variable length. It is often used in warehouses, blood banks and aviation KuaiDi package management work,
128 yards ( Code 128 ) 128 yards ( Code 128 ) is a variable length of continuous letters.