There are many types of barcode scanners available on the market as of now, and some of them are really impressive. For example, the laser scanner is a very interesting piece of equipment once you understand the principle behind it. One of the most famous alternative to laser scanners are CCD based scanners.
CCD scanners are a different kind of scanners as they don’t have any moving parts thus they’re more reliable and less prone to failure. Another type of scanner is the 2d barcode scanner which is the most popular type of scanner. You’ll see it in almost any shop, may it be a clothing shop, a hypermarket or just your regular corner street shop.
Laser scanners use moving mirrors and light diodes and are more likely to fail in a shorter amount of time, whereas CCD barcode scanners use LEDs that are known to last 10 times more than light diodes. 2d barcode scanners also make use of the CCD technology to function.
The principle behind the CCD technology isn’t in any way mind blowing – a CCD scanner uses an array of small light sensors that are pointed at the barcode section on a product. The way these scanners work is that they form a sort of grid of tiny laser like lights on the surface of the barcode part of the product. Because barcodes are usually printed on white backgrounds a part of that light emitted from the scanner is reflected to a receiver inside the head of the scanner. That light is translated into a voltage using a photovoltaic cell, and that amount of voltage corresponds to a single type of product in the store.
After the information is sent from the scanner to the computer it’s then cross referenced to a database – which is also stored on the computer – to which the scanner is connected to. All this stuff happens in a matter of nanoseconds – the reader emits a grid of laser like lights on the barcode part of the product. A part of the light is reflected back from the white surface to a receiver placed inside the head of the barcode scanner (also known as a photovoltaic cell) which translates the light into a voltage and after wards cross references it to a database to find out what product it scanned.
And that’s just how barcode scanners work.
Source: Ezine Articles – Matthew Brockly