Actually, a bar code works in much the same way as an ordinary flashlight -by reading the reflected light from a surface. The process begins when a device upc directs a light beam through a bar code. codes The device upc contains a small sensory reading element. This sensor detects the light being reflected back from the bar codes code, and converts light energy into electrical energy. The result is an electrical signal upc that can be converted into data. Bar codes are measured by the width of the narrow bar and codes are recorded in mils, or 1/1000 inch. A 15 Mill bar code, for instance, has a narrow bar that is 15/1000 inches upc wide. Further, "quiet zones," codes or blank spaces to the left and right of bar upc code symbols, are included to insure the bar code can be read. It''s a three-step process. First, an input device must convert light energy into electrical energy. There are a variety of input devices, each with its own unique characteristics.

Further, the CCD has a codes limited width, and upc will not read bar codes that are wider than the codes face of the input device. It is largely popular for use in point of sale applications. The laser scanner is perhaps the most popular bar code input upc device. A laser scanner need codes not be close to the bar code to do its job. A standard range laser scanner can read a bar code from about 6 to 24 inches away, and a long range scanner can read one from perhaps 2 to upc and codes 8 feet away. An extra long-range device can even read a bar code 30 feet from the device. Laser scanners vary in price from $200 to $2,000 and come in a variety of models. A decoder may be located inside or outside the input device. An internal upc decoder takes up codes less upc space and is less expensive, but it is also less functional. An external codes decoder is a bit more expensive, but is also more functional, with the capabilities to manipulate data and accommodate multiple input devices on a single port.

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