Barcode readers are electronic devices that allow you to read the information contained in a bar code and transmit it to the POS terminal or computer. Barcode readers are present in all areas of society, because bar codes are massively implanted in the industry, companies or institutions, in tasks such as control stocks, invoicing, control of presence and access, quality control or process control. Features of barcode readers basically consist of three components: scanner: reads the barcode symbols. Decoder: the read barcode scans and converts the information to an appropriate data format. Communication interface: allows the connection between the reader and the computer. Usually barcode readers transmit real-time data to the computer that contains the database, although sometimes the own reader stores the information in its memory. Some readers barcode they incorporate an LCD screen that displays the information corresponding to the reading, very useful function in application of inventory or supplies. The main advantages of bar codes are: speed in data capture.

Elimination of typing errors. Ease of use. Low cost of implementation. Connection see how barcode readers connect to the computer: corded barcode readers: USB port, RS-232 serial port or PS/2 keyboard port. Wireless barcode readers: Reader connects via Wi-Fi or Bluetooth to the communications database and load. Barcode readers work mode has three working modes: Manual: pencil or pistol-shaped.

Fixed: they are fixed to the wall or countertop. Semi-fixed: they have support and support both manual use as fixed. Reading technology there are several technologies of reading on barcode readers: stylus: has a light source and a photodiode at the end. When you move the pen to the barcode through the photodiode measures the intensity of the reflected light and captures the information. Laser: work like the stylus, except that the light source is a laser, well a single line (one-way, need to orient the code) or several (omnidirectional, just submit the code). CCD (Charge Coupled Device): capture the code through a series of hundreds of small light sensors lined up in a row. Camera: a camera and image processing techniques are used to decode the barcode. They tend to be CCD cameras with sensors arranged in a two-dimensional array. Mobile phones can function as readers of barcode thanks to the built-in camera, having been developed optimized 2D bar codes for mobile phones, such as codes QR.