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It is not commonly known that a Japanese car parts manufacturer, DENSO CORPORATION, invented Quick Response (QR) codes, though these are such a widely used technology that you see them almost every day. This article introduces how QR codes, an innovation made in Japan, were invented and why they have become widespread.

* A division of DENSO CORPORATION started development of QR codes and then transferred the project to DENSO WAVE INCORPORATED.

(Fig.1) QR Code
(Fig.1) QR Code

To create new businesses beyond automobile manufacturing
(impetus and recognized issues)

QR codes were invented in Japan in 1994.

At that time, the future was uncertain after the collapse of Japan's economic bubble. As a car parts manufacturer, DENSO was seeking business ideas in new fields beyond automobiles.

The company then turned its attention to two-dimensional codes.

Conventional one-dimensional codes such as barcodes transmit information based on line thicknesses. However, each barcode can only record 20 alphanumeric characters. In addition, as the technology invented in the U.S., barcodes do not support Japanese Kanji characters.

Although one-dimensional codes only retain information laterally, two-dimensional codes can retain information longitudinally as well; therefore, they can record a large amount of data.

Hara Masahiro, who was then an engineer at DENSO (he currently works for DENSO WAVE), expected that one-dimensional codes would eventually hit a technical wall, so he decided to develop two-dimensional codes that can be read at high speed.

Hara's personal ambition was to make DENSO globally famous someday. Since DENSO is a car parts manufacturer, it is rare to see products with the DENSO logo around town. That is why he decided to develop world-class two-dimensional codes to make his dream come true.

(Fig.2) One-dimensional code and two-dimensional code
(Fig.2) One-dimensional code and two-dimensional code

The 20-year-old invention is still the best.
(Details of the invention and design)

To read a two-dimensional code at high speed, a machine must accurately recognize the code’s position.

The machine must also be able to recognize the code’s orientation (up/down, right/left) because the code may be read from various angles in factories and elsewhere.

Hara came up with the idea of adding characteristic patterns (finder patterns) to the codes so that machines could correctly read them.

The most significant innovation of QR codes is the placement of this characteristic pattern (finder pattern) in three corners of each QR code.

This enables machines to accurately identify the code’s orientation (up/down, right/left) and the area occupied by the code at high speed. The invented two-dimensional codes can record about 200 times as much information as conventional one-dimensional codes even though the amount of reading time remains the same.

No better two-dimensional code has been invented since the invention of QR codes over 20 years ago.

(Fig.3) QR code's finder pattern
(Fig.3) QR code's finder pattern

Finding the golden proportion with all his might at the end
(travails until completion)

However, Hara did not invent today's QR codes neither quickly nor effortlessly. He worked very hard to come up with the characteristic pattern (finder pattern) with which machines can correctly recognize QR codes.

Hara kept trying to find a pattern that enabled machines to correctly recognize the codes, but he did not come up with any good ideas for a long while.

After racking his brain, he decided to return to his starting point as an engineer: act before you think. You can generate new ideas, even if they fail.

Hara examined every piece of printed matter, such as printed characters and patterns. This led to him finding a pattern that seldom appears.

The pattern is a square pattern with a golden proportion in which black and white parts are placed with a ratio of 1:1:3:1:1. When such a square is placed in the three corners of a QR code, machines can accurately recognize the code. In addition, because the ratio of black and white parts (1:1:3:1:1) is constant with respect to the reading direction, the QR code can be read easily from the side or an angle.

(Fig.4) Finder pattern's ratio of black and white parts
(Fig.4) Finder pattern's ratio of black and white parts

Why have QR codes become widespread?
(How industrial property rights contributed to the invention)

Although QR codes clearly have great basic performance, there is another factor that drove their spread: DENSO made the specification open and the patent available to everyone.

As a general rule, you cannot use others' patents without permission. However, because DENSO made the patent available freely, everyone everywhere can easily use QR codes without worry.

As a result, QR codes have found a variety of uses that DENSO did not expect.

For example, airlines have employed QR codes for tickets, while cellphone carriers added a function to cellphones for reading QR codes. In this way, various companies have come up with ideas that they realized one after another. This has led to QR codes continuing to spread around the world; today, QR codes are used on many occasions.

(Fig.5) Letters patent on the QR code and Design drawing in the prototyping phase
(Fig.5) Letters patent on the QR code and Design drawing in the prototyping phase

Can DENSO make a profit if QR codes are free of charge?

Patents are intended to disclose inventions to benefit society. In exchange for such disclosure, an inventor can exclusively use the invention for 20 years. Unlike patents, trademarks can be exclusively used semi-permanently by renewing them.

So, DENSO thought that they could indefinitely use QR Code as a trademark, while the patent for QR codes would expire in 20 years.

Once QR codes became widespread, DENSO asked user companies to add a sentence when using QR codes, stating that QR Code is a registered trademark of DENSO (currently DENSO WAVE). Trademarks clearly inform shoppers about the makers of products. In other words, the company promoted QR Code as a trademark of DENSO (currently DENSO WAVE) by asking user companies to display the company’s name alongside the QR Code trademark.

DENSO making this request after the widespread of QR codes proved to be effective. If DENSO had done so before QR codes had spread, user companies could have avoided using the QR Code trademark, and the general name "two-dimensional code" may have become commonplace.

In this way, the company name of DENSO has appeared on catalogs, brochures, and websites of various companies as QR codes have spread. This has achieved exceptional advertising effects, including higher name recognition and promotion of the company’s technological capabilities.

As QR codes spread, DENSO started receiving inquiries from many customers about problems they were having.

The company quickly identified such problems to be valuable opinions from customers and leveraged them in product development. DENSO has provided new code readers and services ahead of its competitors and earned profits.

An example of a product created based on a customer’s consultation is the system for attaching a QR code to a train door and linking it with platform doors for open/close control.

(Fig.6) Bureau of Transportation. Tokyo Metropolitan Government - Train door's QR code
(Fig.6) Bureau of Transportation. Tokyo Metropolitan Government
Train door's QR code

What is special about Hara, who achieved this innovation?

What is special about Hara, the person who realized this revolutionary innovation in Japan?
Hara says, "Innovation requires the ability to find issues rather than the ability to solve issues. I believe that finding issues is the shortest route to innovation."
So, how can one find issues?

When he was a new employee, his supervisor told him to go to the actual site if he had no idea about what to do. The supervisor meant that one can develop one’s ability to find issues by going to the actual site because issues only really exist at the actual site.
However, as a new employee, Hara often had to apologize for machine defects when he visited a site in response to a customer’s request. So, he did not like going to the sites.

Although he was not so good at talking with customers, he realized the importance of finding issues as he gained experience and learned, visiting sites with the supervisor.

(Fig.7) Mr. Hara and QR code
(Fig.7) Mr. Hara and QR code

One particular experience of failure brought home the importance of finding issues.
At the start of his career, Hara was technology-oriented and believed that if one created technologically sound products, they would spread around the world.

Hara used to develop an Optical Character Recognition (OCR) device for recognizing characters.
People cannot understand what information a barcode contains by looking at it. On the other hand, machines cannot understand written characters. Hara started the development of OCR, thinking that it was technologically interesting if machines became able to understand information that people can by recognizing written characters.

Back then, OCR did not recognize some characters well. Hara thought that this would not cause problems in practice if people read and manually input such characters. However, customers did not use the OCR at actual sites because they did not want to trouble themselves with the time-consuming task of manually inputting the characters that the OCR did not recognize. Hara then realized that what matters is not technology but users’ perspectives. He now believes the importance of finding issues based on his experiences in which products that solved users’ problems sold well even when they did not employ state-of-the-art technologies.

Thus, gaining the ability to find issues and solving issues at actual sites is the starting point for innovation.

Japanese inventors have created global infrastructure
(Effects of the invention)

It is no exaggeration to say that everyone in the world now uses QR codes daily. For example, you use QR codes to pay at convenience stores or to get on a plane.

Without QR codes, life would be very inconvenient. You can say that QR codes have already become essential information infrastructure. QR codes also have the advantage of low implementation costs, making them easy to use even in developing countries.

Message from Hara

Be passionate about what you like even if you fail.
Dreams come true someday.
Keep pursuing your dreams without giving up.
You can keep doing what you like for your whole life.

(Fig.8) Inventor of the QR code -Hara Masahiro
(Fig.8) Inventor of the QR code
Hara Masahiro
Chief Engineer, Edge Products BU

* QR Code is a registered trademark of DENSO WAVE INCORPORATED.

Source: Documentation from DENSO WAVE INCORPORATED

[Last updated 4 July 2022]


General Affairs Division,

Japan Patent Office