The modest QR code, with its matrix of black and white squares, has become an instantly recognizable symbol of the digital age. A quick scan lets you pay for products, board a train, open a door, view a menu, and a myriad of other things. Although each encodes unique data, all QR codes share an identical feature: large squares in the corners. These squares, called search patterns, only appear in three of the four corners, and there’s a good reason for that.
Positioned at the top left, top right and bottom left, this pattern tells the device reading the QR code which direction is “up”, allowing for accurate scanning. So when you use your smartphone’s camera to read a QR code, you don’t have to worry about the orientation of your phone because the reader knows that the corner without a large square is the bottom right corner of the code. Test it the next time you hold your phone up to a QR code by framing it sideways.
You will find that the handset’s code reader has no trouble recognizing and scanning it. Once you know what these three squares do, the rest of the QR code should start to look less like random noise and more like a carefully structured system, because that’s exactly what it is. Clever design makes it possible to pack a huge amount of information into a small pattern, which is why we haven’t run out of QR codes yet, even though they’re everywhere.
The 1:1:3:1:1 ratio, essential
The QR code first appeared in 1994, but at the time it was not seen in public spaces. It was created by a small team led by Masahiro Hara – an engineer at auto component maker Denso Wave – to track auto parts. The idea for QR codes came from the popular board game Go. Hara designed them as a sturdier, higher-capacity alternative to traditional barcodes. In the late 1990s, QR codes began to become more widespread, but primarily in industrial settings.
As camera-equipped cell phones became popular in the early 2000s, codes were increasingly used by the general public to access information. The proliferation of smartphones led to the adoption of the distinctive square-shaped QR code, and today it’s almost impossible to go an entire day without encountering at least one – although you should think twice before scanning certain QR codes. Creating the search template was a challenge, as it had to be unique enough to avoid being confused with regular printed content.
After analyzing a wide range of print media such as magazines, the development team realized that a specific ratio between white and black areas – 1:1:3:1:1 – almost never existed. So the report was incorporated into the QR code’s search pattern, allowing scanners to lock onto it regardless of surrounding text and images, or scanning angle. The 1:1:3:1:1 ratio became the design framework for the QR code, and by using a pattern rarely found in printed materials, the QR code became a global standard for fast and reliable scanning.
