Its so quick you missed it! Millions and millions of products are being scanned each day. In an instant the barcode is read by the scanner, and its price and product details appear on the cash register. But how exactly are the chosen items scanned into the store inventory system? Find out this and more as we delve into the mechanics of the barcode scanning system.
A barcode scanner has 3 parts: (i) the Illumination System (ii) the Sensor / Converter and (iii) the Decoder
A red light is emitted from the barcode scanner. The sensor detects the variations in reflected light produced by the changes in the light and dark areas of the barcode image lines and bars. The analog signal is converted into a digital signal. This digital signal is confirmed, validated and converted once more to be read by the computer.
ILLUMINATION SYSTEM
Single Point LED – (barcode wand reader and barcode slot reader). The barcode is illuminated from a ball-type opening from either a single- or paired LED. There must be physical contact of the ball-type opening and the barcode.
Since there must be movement of the reader by the scanning operator to detect the barcode, general wear and tear to the reading device as well errors do occur.
Linear Multiple LED – (CCD scanners and linear imagers). Several LEDs are lined together used in conjunction with photocells to detect reflected light.
The proximity of LEDs and photocells must be relativley close as their power outpout and ability to detect light is low.
Laser – A single red laser diode is used in conjunction with one or more mirrors. Oscillation of the laser or the mirror achieves a single red line.
Depending on the laser and mirror, much greater distances are achieved than using LEDs.
LED Imager – uses advanced LEDs and greater sensitivity photocells that achieve improved performance over the single point and linear multiple counterparts.
SENSOR / CONVERTER and DECODER
Most scanning units now have these two steps built in together. The reflected light is converted to electrical signals, which in turn are converted into a binary sequence. This binary sequence is then interpreted by the machine into numerical digits that represent the barcode number.
The resulting information is then used by the
cashier machine to match the barcode number with the number on its system.
Since each store inventory system differs, the first time you take your product
and the barcode to the store to be scanned, they manually enter the product
details into the system.
If you wish to learn more about barcodes or have a question, comment below or
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will be happy to assist you!
