The thought comes to mind about why do the scanners at the checkout counters use a red laser light to illuminate the UPC barcodes (history and technical data here).
I can point my phone camera at the QR codes on advertising and it will read the ‘barcode’. The camera doesn’t need a laser, it just uses the room lights.
The barcode scanner uses hardware to sequentially scan the barcode, and the camera uses software to scan the image of a barcode in memory. Long ago, when UPC labels were standardized, the microcomputer was not a small handheld unit like it is today. The electronics of the early 1970s did not have a microprocessor, which was being developed about that time. The hardware depended upon much simpler electronics, with error detection and corrections added to the bar codes. The electronics were not able to be ‘programmed’ by software like modern devices. Hardware was defined before manufacture, so the UPC labels had to be standardized so the hardware was not confused.
At that time when the standards were finalized, there were no cameras available for this app. This is why they standardized on using a laser to illuminate the barcodes.
One very important attribute for barcode labels is error detection and correction. It’s very important that the scanner get the barcode correctly or reject it as having errors. The wrong barcode could overcharge or undercharge the customer and show errors in the inventory.
Today, things are dramatically different. One can download an app for scanning a barcode or QR code, and when the software is working, it can try over and over to make sense out of the printed label. The software can scan and read multiple label types.
Originally UPC labels only had 12 digits, nothing else. A QR code can have all characters. I went online and created this QR code with a QR code generator. Here’s the URL for this blog.
https://rustybolt.info/wordpress/
I think that in the near future, we won’t have a person at checkout counters. Some stores have already eliminated most of their clerks and gone to automated checkout. The only thing that seems to be a hassle is getting those plastic bags to open up so the items can be put inside. They are going to have to do what Costco does: stop supplying bags and use the leftover cardboard boxes.
