We have all seen barcodes on products we purchase, but there are many other places barcodes are used. And there are many types of barcodes; you are probably familiar with the standard barcodes placed on products called 1D (dimensional) bar codes. These 1D barcodes provide a graphical representation of the UPC (Universal Product Code). These barcodes allow a cash register (which has a built-in computer) and a barcode reader to "read" 1D barcodes. But there are also 2D barcodes which can contain many times more information than 1D barcodes.
Most people think the scanner reads the black bars on a barcode, but really what the scanner is reading is the spaces between the bars. The scanner has a laser which projects a beam; the beam is then moved across the barcode, usually through reflecting the laser with a multifaceted mirror which is rotated by a motor. The laser bounces off of the white spaces between the bars on the barcode, and is picked up by a light receptor within the unit which converts the light to a digital signal that the computer can read.
Traditional 1D barcodes can contain up to about 16 alphanumeric characters. In the case of a UPC code, the barcode contains the manufacturer ID number and the item number. The barcode also contains a space on the far left and right which tells the scanner where the barcode starts and stops. There is a section called a "Module Check" which is like a checksum telling the computer if the barcode has been read correctly or if it has been corrupted.
2D barcodes (also called QR, Data Matrix, Cool-Data-Matrix, Aztec, Upcode, Trillcode, Quickmark, shotcode, mCode and Beetagg) can contain up to 7000 characters, and they can come in black and white and colour. There are many applications for 2D barcodes; many states use 2D barcodes as a backup for the magnetic strip on state driving licence. They are also used by shipping companies such as UPS (United Parcel Service), and the U.S. Post Office uses them on Priority mail. Another advantage of using 2D barcodes is they can be read very fast.
A new application which is beginning to gather a lot of momentum among consumers is the Mobile Barcode application. You use your camera equipped mobile (cell) phone and take a picture of the 2D barcode, allowing you to download information directly to your phone (many cell phones are being equipped with this technology). The 2D barcodes are now being used for a variety of tasks, including getting information about products, purchasing tickets of all types from airline to concert tickets and downloading information about products and services. Universities are even using them to allow students to obtain information on works of art on display. This is a technology which is used extensively in Japan, and is now becoming more popular in the U.S. and other countries.
Barcode future seems to be advancing towards a new technology called Bokodes. These are small LEDs (Light Emitting Diodes) which transmit much more information, and can be read from great distances. They can transmit information directly to cell phones about products, expiration date, quantity and product ingredients. Business owners can place them in store windows to transmit information to consumers driving by such as ongoing promotions, menus, store hours, movie listings, synopsis and a great deal more information.