A QR "Quick Response" code is a two-dimensional or, 2D, barcode that can be read by a mobile handset. The technology they employ was developed in the 90s when Japanese company, Denso Wave, created this barcode standard as an inventory aid for Toyota Motor's factory lines. The name Quick Response comes from Denso's objective of enabling a code to be read as quickly as possible.

 A QR code can hold 100 times more information than a traditional 1D or UPC barcode, and because QR codes are two-dimensional, they can be read horizontally and vertically unlike traditional barcodes which can only be read in horizontally. A QR code can contain up to 1,000 characters compared whereas 1D barcodes can contain a maximum of 20 characters. In effect, a QR code can contain up to 7,089 numeric characters, 4,296 alphanumeric characters, 2,953 binary bytes, or 1,817 Japanese characters.

 QR codes entered the mobile scene when Japan's leading network operator, NTT DoCoMo (News - Alert), established them as the de facto standard for encoding URLs and contact information. Consequently, virtually all mobile phones in Japan now have the capability of reading QR codes. They received their second major boost when they were adopted as the 2D barcode standard within Google (News - Alert)'s Android mobile phone OS.

The QR code is presently a world standard, and is also stipulated by JIS, Japanese Industrial Standards, and International Standards Organization ISO/IEC18004. In addition to being an ISO standard, QR codes have been adopted as the national standard in China and Korea. The QR code is 'Open' in the sense that the specification of the QR code is disclosed and that the patent held by Denso Wave is not being exercised. The word 'QR Code' is actually a registered trademark of Denso Wave Incorporated in Japan, the U.S., Australia, and Europe. 

A Brief History of the QR Code's Approvals

1997: Approved as AIM International (Automatic Identification Manufacturers International) standard (ISS - QR Code)
1998: Approved as JEIDA (Japanese Electronic Industry Development Association) standard (JEIDA-55)
1999: Approved as JIS (Japanese Industrial Standards) standard (JIS X 0510)
2000: Approved as ISO international standard (ISO/IEC18004)
2004: Micro QR Code is approved as JIS standard (JIS X 0510)
2006: Extended version is approved as ISO standard ISO/IEC (News - Alert) 18004:200

Barcode Evolution to 2D

QR codes were developed to meet a market requirement for codes capable of storing more information and more character types, and which could be printed in a smaller space. Consequently, efforts were made to increase the amount of information stored by barcodes, such as increasing the number of bar code digits or laying out multiple barcodes. Initially, the necessary enlargement of the bar code area unfortunately complicated reading operations and increased printing cost. The 2D QR code emerged in response to these problems.

 

Multiple bar code layout

2D Code with stacked bar codes (stacked bar code type)

2D Code (matrix type)

The Traditional QR Code

 The QR code is a specific type of 2D matrix code which Denso Wave developed and was released in 1994, with the primary objective of being a symbol that is easily interpreted by scanning equipment.

A QR code contains information in both the vertical and horizontal directions, whereas a traditional UPC barcode contains data in one direction only. Thus a QR Code can hold much more information than a traditional barcode.

The Micro QR Code

The Micro QR code is a smaller QR code which suits applications that require smaller spaces and smaller amounts of data. Typical applications include IDs on printed circuit boards and other electronics parts. The efficiency of data-encoding is increased with the use of only one position detection pattern. Several variants of the Micro QR have been approved.

 Today, as a typical example, a QR code might appear on business card to enable handsets to automatically save contact information stored within the code directly into their mobile phone's address book. They are also a good means of conveying URLs which can easily be activated by a handset's WAP/web browser. There plenty of good barcode scanners, such as the NeoReader from NeoMedia, which can read both traditional barcodes and QR codes. There are also plenty of QR code generators hosted on the web such as this one from the Zing Project.