Manufacturers : Electronic components : Barcode devices

Bar codes today are widely used for a multitude of commercial applications, such as sales order entry, inventory control, marketing data collection, asset management, and point-of-sale (POS) transactions. Most commercial products have a price tag or product label with a barcode which is scanned in order to ring up the purchase price and/or identify the product for inventory control or other purposes. A bar code is a technique for describing characters by a combination of parallel (vertical) lines of different thickness (width) or arranged at different intervals. Each bar code symbol represents binary information which can be optically read by barcode readers. Bar codes are roughly classified into a WPC code such as a JAN code, a UPC code, or an EAN code and a second code having a variable length. There are generally two types of bar codes in commercial use, a linear (1D) bar code and a two dimensional (2D) bar code. A conventional 1D bar code encodes numbers and letters by using a combination of bars and spaces of varying widths. The 2D bar code can store the data within the code, therefore eliminating the needs for access to a database for getting the information. Large amounts of text and data can be stored securely and inexpensively. A bar code label may be read by a scanner that detects reflected and/or refracted light from the bars and spaces that comprise the bar code characters. The device that reads or captures the bar code information and sends it to the decoder is known as the bar code reader, generally called bar code scanner. Typically, bar codes are read by a bar code scanner by illuminating the bars and spacings in a sequential manner, with the bars absorbing light and the background spacings reflecting light. A typical bar code scanner kit consists of a scanner, decoder, and cable which interfaces the decoder to the computer. The scanner scans the bar code symbol and captures the bars and spaces of the bar code and sends it to the decoder. The decoder translates the bars and spaces into corresponding electrical output and transmits that data to the computer in a traditional data format. Pen type bar code readers have a light source and a photo diode which measures the intensity of the light reflected back from the light source and generates a waveform corresponding to the widths of the bars and spaces in the bar code. Laser bar code scanners work the same way as pen type barcode readers. But laser bar code scanners use a laser beam as their light source, and typically employ either a reciprocating mirror or a rotating prism to scan the laser beam back and forth across the bar code. CCD bar code scanners use an array of tiny light sensors lined up in a row in the head of the bar code reader. CCD bar code scanner measures emitted ambient light from the bar code whereas pen or laser bar code scanners measure reflected light of a specific frequency originating from the scanner itself. Camera-based bar code readers is gaining increasing popularity for reading 2D bar codes due to increased data carrying ability. Camera-based bar code readers use a small video camera to capture an image of a bar code. The bar code reader then transmits that information to a computer and uses digital image processing techniques to decode the bar code. Various bar code printing devices have been developed for printing bar codes on stickers. These bar code printing devices usually comprise a base frame which holds a sticker reel, a cover pivoted to the base frame which holds a ribbon reel, a motor drive, and a transmission mechanism coupled between the motor drive, the sticker reel and the ribbon reel.

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