Representing numbers
Bar codes represent series of numbers. A bar-code scanner can then read the number into a computer, and retrieve price and information about the item or product. Bar-coding is used in many industries, from retail and grocery stores to libraries to package-shipping to health care. A bar-code reader, or "scanner," is needed to read a bar code.
Bar code design
Most bar codes represent numbers using black and white stripes of varying widths on a white background. Each numeral in a bar code is represented by a combination of thick and thin white and black bars. There are many different standards for bar-code design, depending on the intended use and the amount of information that is to be conveyed by the bar code.
Another design option is the two-dimensional code, which uses rectangular patterns to make the code.
Scanners
Bar-code scanners use Light Emitting Diodes (LEDs) to scan the bar code, and reflect the image onto a Charge-Coupled Device (CCD). The CCD transmits the information to a computer that retrieves information about the product from a database, and also adds information to the database that the product was scanned.
Scanner Varieties
Bar codes and scanners are used in a variety of ways. The most common is the counter-top scanners found in most super markets and large retail stores, which use lasers to scan the bar codes. Handheld scanning "guns" also are used in stores that sell large items in customers' carts. Portable handheld scanners are used by store employees to order inventory (generally using bar codes printed on the price-marker tags for each item). Some retail stores even have handheld scanners for customers to use to add items to gift lists (such as wedding registries).
Digital camera technology is also being used to read bar codes. As most digital cameras use CCD technology, it is easy for a camera to be used as a bar-code scanner. Software such as Delicious Library, which allows users to scan the bar codes of their home movies and books, are becoming popular.
Some companies use bar codes to promote products on billboards, requiring potential customers to use digital camera phones to read the bar codes. This is used for promotions, ad campaigns, and by graffiti artists in Japan, and is gaining popularity in the West.
Tags: bar-code scanner, codes represent, handheld scanners, information about, read codes, retail stores, scan codes