QR Codes are everywhere. You can see them at shop entrances and cashier counters. Today, QR Codes are commonly used for electronic payment and information access. A quick scan can open a connected website. But what exactly is a QR Code? Are all QR Codes the same? technine explains the real identity of QR Codes.
The Father of QR Code: Masahiro Hara
Although QR Codes became widely used only in recent years, they were created in 1994 and now have nearly 30 years of history. QR Code stands for Quick Response Code, named because the inventor wanted the code to decode information quickly.
There are actually different types of two-dimensional codes. QR Code is one type of two-dimensional code and the most widely used, so many people commonly treat “two-dimensional code” and “QR Code” as the same thing.
Masahiro Hara, known as the father of QR Code, was born in Tokyo, Japan. After graduating from university, he joined DENSO, a company under Toyota, and became an engineer. At age 37, he studied existing two-dimensional codes and found that reading speed was slow, taking around three seconds on average, and the error rate was high. Even minor stains could prevent successful reading.
Hara later discovered that low reading efficiency and high error rates were mainly caused by machines struggling to locate the code accurately and distinguish the code from surrounding images. After months of measuring black-and-white line ratios across printed materials, he found that the least common ratio was 1:1:3:1:1. He used this ratio to design the square positioning marks and developed a scanner specifically for this type of code.
With this design, the new two-dimensional code, QR Code, could store more than 400 times as much information as a barcode. Scanning speed improved significantly, error rates dropped, and even slightly damaged codes could still be read accurately.
Are All QR Codes the Same?
Common QR Codes have 40 different size versions. Versions differ by storage density and structure, so their composition and capacity are not identical. QR Code sizes are marked by version. Version 1 is 21 by 21 modules, Version 2 is 25 by 25 modules, and Version 40 is 177 by 177 modules. The higher the version, the larger the QR Code and the more information it can carry.
You may have seen QR Codes that include logos. Error correction means that when some information is missing, other parts can compensate so the overall information remains readable. In simple terms, even if a QR Code is missing a corner or is not fully recognized, the information may still be scanned. This is something one-dimensional barcodes cannot do.
However, the higher the error correction level, the less information a QR Code of the same size can store. This is because part of the space that could store data is used for error correction backup, reducing normal storage capacity.
The Subtle Structure of QR Codes
The most important parts of a QR Code are the three square positioning marks at the top corners and lower left. These marks allow scanners to recognize QR Code direction in 360 degrees, so even if the code is scanned upside down, the reader can determine the start and end points and avoid reading errors.
Different QR Code versions have slight structural differences. The higher the version, the more information it contains and the more alignment patterns it may include to prevent reading errors. The actual data is stored in the data and error correction code area, which includes both the real information region and the error correction region.
After this quick introduction, you should have a clearer understanding of QR Codes. Although QR Codes are widely used in everyday life, do you know their advantages? technine will introduce QR Code features and benefits in the next article.
Translation supported by AI.