QR code is a kind of two-dimensional bar code. QR comes from the abbreviation of “Quick Response” in English, which means quick response. The inventor hopes that QR code can make its content be decoded quickly. The QR code can store more data than the normal barcode, and there is no need to line up the scanner when scanning like a normal barcode.
The QR code of the QR code is an abbreviation of Quick Response. This QR code can be read quickly, compared to the previous barcode.
QR codes can store richer information, including encryption of text, URL addresses, and other types of data. The QR code was invented by Denso-Wave Corporation of Japan in 1994. The QR code standard JIS X 0510 was released in January 1999, and its corresponding ISO international standard ISO/IEC18004 was approved in June 2000. According to Denso Wave's website, the QR code is an open standard, the QR code specification is open, and the patent interest held by Denso Wave is not enforced. In addition to the standard QR code, there is also a format called "micro QR code", which is a reduced version of the QR code standard, designed primarily for applications that cannot handle larger scans. The micro QR code also has multiple standards and can store up to 35 characters.
Because it no longer works by linear scanning, it uses the infrared light-enhanced camera to work directly to identify the QR code image in the image captured by the lens, so the requirement for the reflection angle is reduced. The QR code scanner can even "scan" the barcode displayed on the LCD screen (Recognition) (but when it is vertically above the bar code on the screen, it is easy to recognize due to the reflection of the infrared light source on the screen), so you can directly scan the barcode displayed on the screen such as mobile phone.
The QR code is square, only black and white. Three of the four corners are printed with a smaller square pattern like the "back". These three are patterns that help decode the software. The user does not need to align, and the data can still be read correctly regardless of scanning at any angle.