How Black and White Squares Changed the World
It Started with a Barcode Complaint
In the early 1990s, a Denso factory (now Denso Wave) in Aichi, Japan used barcodes to manage auto parts. But the barcode had a serious limit. Because it encodes information only in the width and spacing of a single row of lines, one label holds very few characters - the EAN-13 symbol used across retail carries just 13 digits. To record a part number, a production date and a process step, workers had to attach several labels to a single part and scan them one at a time, raising a scanner hundreds of times a day.
"Could a single scan capture far more information?" That plain question became the starting point of an invention that changed the world. Inventions rarely begin with grand theory; more often they grow out of a serious attempt to fix the problem right in front of you. The task went to Masahiro Hara, an engineer in his thirties at the time, and a team of just two people.
Inspired by a Go Board
Hara's team removed the barcode's "single row" constraint and set out to build a two-dimensional code that carried information both horizontally and vertically. Going two-dimensional, however, made it much harder to tell a computer where the data begins and where it ends.
The clue turned up in an unexpected place. During a lunch break game of Go, the pattern of black and white stones on the grid caught Hara's eye: information could be expressed as black and white cells, just like a Go board. He then designed a structure that places a large square marker (a finder pattern) in three of the four corners. Once the three markers are located, the pattern's position and size are fixed, and the contrast with the one unmarked corner reveals its tilt and orientation. That is why it can be read instantly from any angle.
Completed in 18 Months, Then Opened Up the Patent
About 18 months after the project began, the two-dimensional code was finished in 1994. A single symbol holds up to 7,089 numeric characters, or up to 4,296 alphanumeric characters. It reads about 10 times faster than a barcode, and it carries error correction built in: the strength is chosen from four levels, and at level H the original content can be restored even when up to about 30% of the data (codewords) is missing. Staying readable in a factory where oil and scratches are routine is what made the field trial a success.
The most important decision, though, came afterwards. Denso (now Denso Wave), which developed the code, published the specification and declared that it would hold the patent without enforcing it. In 1999 the code was approved as a Japanese Industrial Standard for two-dimensional codes, and in 2000 it was adopted as an ISO international standard. As long as you follow the standard, anyone can use it with no application and no licence agreement. Charging royalties would have brought enormous revenue, yet opening the technology instead of fencing it in multiplied its value.
From a Japanese Factory to the World's Smartphones
The black-and-white pattern, at first used only for parts management on the factory floor, spread to logistics, healthcare and food traceability. The turning point came around 2002, when Japanese mobile phones began shipping with the ability to read the pattern. Camera phones themselves had appeared in 2000, but once a handset could analyse a captured image and pull a URL or an email address out of it, the pattern became part of ordinary consumers' daily lives.
In 2017, Apple built scanning into the iPhone camera app as standard, and adoption exploded worldwide. During the 2020 pandemic the technology became a piece of social infrastructure, used to show menus without contact and to manage vaccination certificates. A project started by two engineers in an Aichi factory had changed the lives of 8 billion people three decades later.
How an Open Technology Became a Universal Tool
Being free to use is not enough to make something a universal tool. This pattern works across borders because the standard documents are published so anyone can check the specification, and because a symbol built to the standard reads the same way on your own equipment and on another company's. Denso Wave opened the rights and went on running its own business in industrial scanning equipment. Opening a technology to everyone and earning a living from it turned out to be compatible.
In 2014, the development team of five including Masahiro Hara received the European Inventor Award. The category they won was the Popular Prize, decided by a public vote held over the internet. A mechanism born from a nuisance on a Japanese factory floor was chosen, two decades later, by the votes of people in Europe. The value of a technology is maximised not by keeping it to yourself but by having it widely used - this invention is the proof.