Denso's Clever New Code

Although barcodes may make grocery shopping a comparative ease when contrasted to how it used to be, when the checkout clerk attempted to decipher the smudged ink digits that had been hand-stamped onto the boxes and cans, according to Ken Ishikawa, senior manager, New Business Promotion Group, North America, Denso International America, Inc. (Southfield, MI), and Koji Mori, senior manager, Engineering, Denso Sales California, Inc. (Long Beach), barcodes are generally too-limited in the amount of information that they can provide for industrial applications.

Denso is, of course, one of the world's leading automotive suppliers, and part of the Toyota keritsu. It manufacturers a wide-range of automotive components and accessories, including air conditioning systems, heating systems, alternators, starters, small motors, spark plugs, ignition products, relays, traction control devices, emissions control devices, electronic fuel injection systems, radiators, instrument panel devices. . . and a whole lot more. In Denso Manufacturing Tennessee, Inc. (Marysville and Athens), for example, they are manufacturing starters, alternators, instrument clusters, instrument cluster parts, electronic control units, and pressure sensors. These are all high-volume products. Some of the elements used in the manufacture of many of these devices come from Japan.

So given (1) the wide array of things that Denso makes as a corporation and even within individual plant sites, (2) the base in Japan but manufacturing plants not only throughout North America, but in Europe, South America, Australia, and Asia, and (3) the connection to Toyota, the engineers at Denso figured that there had to be something better than a barcode, a symbology that could handle more information, including Japanese Kana and Kanji characters. Ken Ishikawa points out that since Denso is one of the Toyota-affiliated companies, it has long used kanban. Because of its expertise in things electronic (they even manufacture cellular phones), Denso engineers developed kanban software and hardware—25 years ago. These people are experienced, to say the very least.

Ishikawa observes, "In our operations, millions of parts are being produced. There is a lot of information required during manufacturing because the various car manufacturers require so many features and characterizations and part differences. We needed more information."

Better Readability

So they developed a new 2D symbology (barcodes are essentially one dimensional). It's called "QR Code"—with the letters designating "quick response." The QR Code has been approved by the Automatic Identification Manufacturers International, Inc., as an international standard. Although Denso holds the patent on the QR Code, it is offered in the public domain, which means that other companies can use it without paying a fee to Denso. The company does, however, offer QR Code hardware and software on the market, so there is the possibility that people might source their QR Code resources from Denso, but that is not a requirement.

The "quick" in the name of the symbology relates to the fact that it can be read at a high rate. It is possible to read, for example, 100 numeric digits of data in 30 msec. One of the reasons why QR Code is quicker than alternatives is because of the three position-detection patterns at the top upper right and left and bottom left of the design. One additional benefit of these locators is that omnidirectional reading can be performed. In other words, regardless of the way that the scanner is presented to the code (i.e., think of a user wielding a hand-held scanner) or how the code is presented to the scanner (i.e., think of boxes with code labels affixed that are randomly arranged on a moving conveyor belt), the code can be rapidly read.

The QR Code, because it makes use of both horizontal and vertical axes for information, is said to be 100 times more info-packed than a barcode label of the same size. Which means QR Code labels can be used in places where barcodes cannot be as efficiently used, such as in electronics manufacturing. In one application, QR Code is being used in printed circuit board processing to provide manufacturing information. The necessary details are encoded on a label that measures just 1 cm2. Barcode labels had been used, but the limited amount of real estate on the board resulted in a much more limited amount of information on the barcode label as compared with the QR Code label.

Information Density

This information density also permits the utilization of QR Code on kanban tickets that Toyota Motor sends to suppliers. The information enclosed includes all of the information (e.g., part number, delivery date, quantity, etc.) needed for production. Denso is using QR Code on its purchase orders for vendors. By having the information scanned by the vendor upon receipt and the scanned information going into the vendor's computer system, data entry errors are eliminated.

Speaking of errors, it is even possible to read QR Code in situations where up to 30% of the label is obscured or damaged.