How barcode scanner works for reading barcode values
How barcode scanner works for reading barcode values
Do you know what barcode scanners are? These are extremely simple devices consists of light source, photo diode and simple decoder or complex CCD that helps in scanning barcodes in very simple way.
Barcode scanner basically consists of 3 parts like illumination system, the sensor / converter, and the decoder.
Simple Working of Scanner is as follows :--->
Illumination system: Illumination system scans parallel and vertical lines of codes with Red light. There are multiple numbers of illumination systems commonly used in barcode scanners such as single point LED, Linear multiple LED, Laser, LED imager etc.
Sensor/Converter: This consist a photo detector that easily senses reflected light from illuminated system and generates an analog signal of varying voltage. The voltage fluctuations based on whether the sensor sees the reflected light from the white spaces because the black bars absorb the red light means Voltage form with high peaks used for white space and for troughs used for black spaces in the barcodes and generate 2 dimensional wave forms.
Decoder: Now it’s the working of decoder starts that performs variety of functions. First, it analyses the 2D digital signal wave form from the sensor, and tests for uniformity of the white space (high signal) on each side of the digital signal, and uniformity between the peaks and valleys of the digital signal to see if it can be taken as a valid barcode or not. Then, it tests the digital signal for conformance with any and all of the barcode symbologies it's designed and set up to read. Then this signal is transferred to decoder box was connected to the host PC.
