iPhone A No-Go For Barcodes

I went to my local Apple Store today to exchange the Incase cover I purchased previously for a different color.  In doing so, I wanted to see if the infrared scanner used at the register could scan the receipt directly from the iPhone's screen (they emailed the receipt to me the previous day rather than printing it out).  To my disappointment the scanner couldn't pick up the barcode, even though it was clear as day on the screen.  At that moment, my dreams of being able to buy movie tickets, sporting tickets, or even downloading coupons online with my iPhone and not having to print them out (like they are able to do in Japan) flew out the window.  Anyhow, I wonder what it is about the phone that didn't allow the infrared to pick up the barcode.  Is it the glass covering the screen?  Is it the display itself?  Or is it the infrared used at the Apple Stores?

Oh, and I exchanged the black cover for a red one:

Comments

[do da]

It is probably the glass reflects it back. The infrared may not even reach the barcode image

[Sanjay]

Infrared scanners expect to receive a bar code reflected back in the same wavelength that was sent out. The iPhone screen is a LCD (liquid crystal display) which has pixels that are activated by electricity. Unfortunately, shining infrared light on a LCD screen won't produce any sort of meaningful reflection regardless of what is being emitted from the screen (pixels don't reflect, they emit).

[gl4com]

You could do that with a CCD barcode reader and not a laser one, I agree with the previous comment.

Anyway what I suggest for coupons is to use mobile coupons, you will find them here
www.moqpon.com

[bradmurmz]

do da :

Bar codes work on the principal of quantum mechanics... There is no reflection that ever makes it back to the reader. Its an unexplained phenomenon, but when the light touches black it pulls more current from the power source than it does when touching white. The pull on the power source fluctuating back and forth is converted into a digital data stream and sent to the computer. I agree though that the screen probably causes the light to reflect before it can really 'touch' the bar code....

[Patrick]

It may be some combination of the barcode Apple uses, the LCD display, and Apple's scanner because barcodes on the iPhone have been known to work elsewhere. TUAW had a piece on a guy who was able to get American Airlines to scan his boarding pass barcode.

http://www.tuaw.com/2008/04/22/iphone-on-the-road-a-substitute-for-paper-boarding-passes/

[Laird Popkin]

"Bar codes work on the principal of quantum mechanics... There is no reflection that ever makes it back to the reader. Its an unexplained phenomenon, but when the light touches black it pulls more current from the power source than it does when touching white. The pull on the power source fluctuating back and forth is converted into a digital data stream and sent to the computer. I agree though that the screen probably causes the light to reflect before it can really 'touch' the bar code...."

Um, no. Barcode readers all have a camera or a photocell of some sort that measures the intensity of the reflected light.

Barcode scanning of displayed barcodes sometimes works, and sometimes doesn't, depending on the specifics of the scanner and the screen and the barcode. I've seen systems demo'd for years that display barcodes on cell phone screens that are scanned, but I suspect that they're not in general use because of the compatability issues. That is, barcode scanners are calibrated to recognize reflected light from a paper label with ink, and a cell phone display doesn't reflect the same way.

[Hawkins Dale]

I tried this. I decided that real nerds don't carry supermarket loyalty cards: they scan them into a photo album on their iPhone, and just whip 'em out at checkout-time.

Totally did NOT work. Utter failure. Specific results at hawkinsdale.com, but in summary: FAIL.

[That one guy]

That's weird. We just tried it at my work and it worked just fine. We have a regular barcode scanner. I grabbed this image and put in on my phone:

http://www.sagedata.com/images/2007/Code_128_Barcode_Graphic.jpg

It didn't work when it was in landscape mode. If you keep the phone vertical, the image is small and high quality. I think your problem is the quality of your barcode.

[Black Friday Sale]

Whoever said money can't buy happiness simply didn't know where to go shopping. - Bo Derek :o)

[joe]

i work in retail and i have customers who frequently come in using iphones as well as other web enabled devices as coupons. it works fine. sometimes a little pinching or expanding is required but it works. landscape or portrait.

[joe]

i work in retail and i have customers who frequently come in using iphones as well as other web enabled devices as coupons. it works fine. sometimes a little pinching or expanding is required but it works. landscape or portrait.

[Steve Lafreniere]

Laser scanning cannot pickup the fast-pulse pixel illumination from an LCD or CRT display. Imaging scanners, which use optical imaging technology (i.e. digital camera) do not have a problem scanning "on screen" barcodes, since they can digitize and read-back the information (software correllation, vs. hardware decode).

Hope this helps!

Steve Lafreniere
Professional Services Manager
Quest Solution - barcode data capture/wireless services

[d]

Iphone doesnst have an infrared scanner lmao idiot
it does have a camera tho

[Gbayo1]

Hi all,

I was reading through all the comments and was wondering would anyone be able to help me with a problem or provide any suggestions.

My name is Graham and I am currently working on a simple college project. This project involves creating a simple database which stores a number of barcodes. These barcodes must then be scanned and the correct data received from the scanner (e.g. uni or omni-directional). This works fine for the barcodes that are printed on a piece of paper but when I try to scan the barcodes from my mobile phone screen, nothing seems to happen.

As from you answers above, this doesn't seem possible when using a laser scanner.
Is there any way in which this would be possible (i.e. a barcode to be scanned from a generic phone screen)??

Any comments would be greatly appreciated.
Graham

[Dave]

Laser scanners do pick up the barcodes on the iphone. We have laser barcode readers at my work and I tried and it works.