A barcode helps in automatic data identification and collection. This was first invented in 1952 by Bernard Silver and Joseph Woodland. This barcode basically has parallel lines or bards of different width and thickness. The bars represent the binary numbers 0 and 1, and the sequence starts from 0 to 9 which are processed with a help of a computer. This information on the barcode can be read only with the help of a barcode scanner, which needs an optical laser connected to a computer system to read. The code can be read by moving the laser or the barcode pen across the bars, and the computer gets the information embedded in the barcode(s).



So what is this barcode scanner or reader and how does this work? A barcode reader is an electronic gadget which reads the information embedded inside the barcodes. The barcode scanner consists of a light source, photo conductor and a lens. Here the optical impulses are converted into electrical impulses. Most of the barcode scanners contain a decoder circuit that analyzes the image of the barcode with the help of a photo conductor and this is sent to the scanner’s output port. There are three kinds barcode readers; the handheld readers are use for semi-automatic reading, the fixed mount readers are used for automatic reading and finally, the reader gates are used for automatic scanning.

There are four kinds of technologies being used these bar code scanners. The pen type readers have a photodiode and a light source; to read what is on the barcode, the pen has to be moved gradually across the bar. The laser scanner also works just like the pen type reader, here a laser beam is used instead and the light source is just the same. A CCD reader also called as LED scanners use an array of many tiny light sensors which are arranged in a row at the head of the scanner/reader. The main difference between the pen reader and the CCD reader is that, the CCD reader measures the emitted ambient light from the bar; however laser scanners and pen type readers measure the reflected light of a particular frequency originating from the scanner. The newest and the latest type are the camera-based readers which are 2D imaging scanners, which uses a tiny camera to capture the barcode’s image. Here the video camera uses the same technology as in CCD, the only difference is that the CCD scanner has a row of sensors and the camera had hundreds of sensors in two dimensional arrays which can produce an image.