The bar code scanners are called barcode scanners. These are computer peripherals used to read barcodes displayed on different surfaces. Quick and accurate transmission of encoded information was performed by the barcoders in the application. The whole unit compresses a light source, an objective lens and a photo driver for electrical connection of optical signals. In addition, the decoder circuit is also used to evaluate the bar code values provided by the driver, and then this information is transmitted to the output of the reader.
Classification of barcodes
Four types of barcode scanners are most available on the market. Each of these uses different techniques for reading and decoding the barcode.
first Pen Type Readers: Here is the light source and photo diode that are found on the top of a pen or stick. The tip of the pen must be moved to the barcode as a whole. The light intensity reflected from the light source is measured by the light diode and generates a waveform. The light is darkened by the dark bars and the whites reflect. This waveform is decoded by the reader.
2. Laser Scanners: Instead of the light source, they use laser beam instead of pen-type readers. A reflective mirror or rotating prism is used to feedback the laser beam on the bar code. The light-emitting diode is used to measure the intensity of the reflected light.
3. CCD readers: Charge Coupled Device (CCD) readers have a range of small light sensors located on the reader's head. Like a light diode, all sensors are used to measure light intensity. A voltage similar to the bar code generator is generated by the reader, which senses the sensitivity of each sensor.]
4. Camera based readers: Here, a small video camera is used to cover the bar code image. These readers use a very complicated digital image processing technique for decoding the barcode.
Barcode readers are the most important areas of retail, warehouses and industrial areas. Entertainment areas such as movies and music use barcoders in DVD / VHS movie catalogs, CD and MP3 catalogs. The nutrition information in the malls can be read with these readers. Personal and personal inventory collected for bar codes for insurance and other purposes, these readers are useful.