I’m going to show you how a barcode scanner works. I’m going to take you through each of the parts that make a barcode scanner, including the high precision optical components.
A barcode scanner consists of three different parts. These include the illumination system, the sensor, and the decoder.
The barcode scanner “scans” the black and white elements of a barcode by illuminating the code with a red light, which is then converted into matching text.
This makes it so the scanner detects the reflected light from the illumination system (aka the red light) and generates an analog signal that is sent to the decoder.
The decoder then interprets that signal, validates the barcode using the check digit, and converts it into text. Barcode scanners are variable and include diverse capabilities, some are better suited for certain industries due to reading distance and to work volume capacity.
If you go into a grocery store, you’ve seen these in action. If you look closely behind the protective window, you’ll see the optics inside the barcode scanner.
The mirror that you see behind the glass is a first surface mirror, also known as a front surface mirror. It’s a high precision ultra flat mirror with the coating on the face of the glass to ensure accuracy. A standard mirror wouldn’t work as well because it has a double reflection, also known as ghosting.
For more information on front surface mirrors and barcode scanners, check out our website firstsurfacemirror.com. I’ve left you links and information down below.
With the high precision provided by the optical mirror, the scanner is able to read the barcode quickly and accurately from all angles. That’s a huge benefit to customer satisfaction, preventing frustration from items won’t scan or double scan. Additionally, a time delay programmed into the software helps prevent the double scan after the first scan.
The imager takes a picture of the barcode, decordes it, and then outputs the data as a string to a host system for storage or further processing. Though in order to read the barcode, the imager needs to “see” the entire code. However, the imager can’t always be properly positioned directly in front of the barcode due to limited space in the interaction environment.
The best way to combat this, single or multiple bounce mirrors can be implemented to shape the imager’s “line of sight” to the barcode.
Are you working on a barcode scanner project? Leave me a comment below or send an email with your questions!