Shenzhen Rakinda Technology Co., Ltd.

After entering the 1960s, with the rapid growth of Japan, the supermarket of food, clothing and other kinds of commodities began to appear in the cities.

The cash register was used by cashier to manually enter commodity prices, so cashier were often distressed by the numbness of their wrists and “tenosynovitis”.

“Can you relieve the burden on the supermarket cashier?” The presence of the 1d bar code solves this distress. Due to the successful development of POS system, after the light sensor to read one-dimensional bar code,the price will be automatically displayed in the cashier POS machines, at the same time the commodity information can also be transmitted to the computer.

In this way, 1D barcodes are common, but new problems ensue. The problem is that the 1D bar code has limited capacity, and it can only hold up to 20 characters.

“The QR code developed by other companies at the time focused on the storage space of information,” said Mr.Chang, who was responsible for the development of the QR code.

A barcode can only store information horizontally (one-dimension), whereas a qr code can store information in two-dimensions. Mr.Chang’s consideration is that in addition to being able to accommodate a large amount of information, the coding of R&D is need to reading easy .

The biggest task facing the team is how to achieve high-speed reading. One day, Mr. Chang’s mind came up with a quadrangle “positioning pattern”. By placing this figure in a qr code,the qr code can be achieved high-speed reading that other companies cannot emulate.

However, why use the four corners?
“The probability of error is minimal because of the positioning pattern of the quadrangle” Mr.Chang explained.

That is, if there is a similar pattern nearby, the barcode reader will mistake it for coding. To prevent this misreading, the positioning pattern must be the only graphic. After full consideration,Mr.Chang and other people decided to make a thorough investigation of the area ratio of the printing and text in the advertising sheet, magazines, cardboard and other places. The research and development team investigated numerous printed matter day and night, and finally found out the “least commonly used ratio” in print, that is, 1:1:3:1:1.

In this way, the width ratio of the black and white parts is determined. The structure is that a qr code reader module can read the qr code from a 360-degree Angle,and regardless of which direction it is scanned, the encoded position can be calculated once the unique ratio is scanned.