条形码扫描技术（国外英文资料）.docVIP

条形码扫描技术（国外英文资料） Bar code reader is an electronic device, read the barcode printing. As a platform for scanner, it includes a light source, a lens and a light sensor turns light into electrical impulses. In addition, almost all of the bar code reader contains decoder circuit analysis barcode image data provided by the sensor and send the content of the barcode scanner output port. Bar code scanning to the scanner, scanner using its illuminant, bar code reuse photoelectric converter accept reflected light, will reflect light and shade is converted into digital signals. No matter what rules are printed, the bar codes are composed of static zones, starting characters, data characters and terminating characters. Some barcodes also have calibration characters between the data characters and the terminating characters. Bring about static area: the quiet zone is also called the blank area, divided into left and right blank area blank, left blank area is prepared to scan to scan equipment, right blank area is to ensure that correct identification of the end of the bar code scanner. In order to prevent the blank area around (dead zone) in typography is occupied by a unintentionally, can be a symbol of blank area printing (no Numbers printed on the left side of the number, there is no digital printing on the right side ) this symbol was called dead zone. The main effect is to prevent the lack of width. As long as the width of the zone is guaranteed, there is no sign of the bar codes. The origin character: the first character, with a special structure, begins to formally read the code when the scanner reads the character. Data character: the main content of the barcode. The checkout character: verify that the data read is correct. Different coding rules may have different validation rules. The termination character: the last character, which has a special structure, is used to inform the code of the scan, but also ACTS as a validation calculation. In order to facilitate two-wa