A เครื่องสแกนบาร์โค้ด (Barcode scanner) is a scanner that is an optical instrument that is used for reading the barcodes, which are present in a printed manner. It deciphers the data contained in the barcode and then sends the actual data to the computer. As an advantage, all เครื่องสแกนบาร์โค้ด have a decoder circuit that is responsible for the evaluation of the barcode’s image data that has provided by the sensor and send the content of the barcode to the output port of scanner.
Types of barcode scanners
- Laser scanners- First, scan the laser beam back, then forth across the blade. This photo-diode is responsible for measuring the intensity of light that has been reflected from the barcode. Light emitted by the scanner gets diverse brightness with a fixed data pattern. The photo-diode has received circuitry to detect the signals with the same modulated pattern.
- LED scanners- Also known as the charged coupled device, which uses the arrays of hundred tiny sensors lined up in a row towards the head of the scanner. In this, light sensors are tiny because of the bulk of sensors lined up in a row. A voltage pattern that is identical to the pattern in the barcode gets generated in the reader by the estimation of voltage across each sensor present in the row.
The difference between laser and LED scanners– LED scanner will measure emitted ambient light from the barcode, whereas laser scanner will measure the reflected light of a particular frequency.