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Need help understanding barcode reader operation

  1. Sep 3, 2011 #1
    Barcode reader's operation

    I see that a horizontal beam of light is projected on the code and then, what happens. Does the light is reflected back and caught somewhere else if so where and what is this collector? How is it reflected back when code is printed on some non-reflecting body?
    Last edited: Sep 3, 2011
  2. jcsd
  3. Sep 4, 2011 #2


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    Here's a HowStuffWorks video that turned up when I Googled for "How Stuff Works Barcode Scanners":

    While it looks like a continuous line (or other pattern), it's actually a single beam of light being rastered (scanned) across the barcode. The photodiode then picks up the reflected light, correlates it back to the scan position, and "reads" the barcode. More at:

    Some newer scanners take a picture (with a CCD sensor, the same as in a camera), and then analyze that. The natural extension of this is the 2-D barcodes that you see about: those are usually meant to be read by taking a picture with a camera phone, without needing to laser scan the barcode.
  4. Apr 12, 2013 #3
  5. Apr 12, 2013 #4


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    There are bar code reading apps for all (?) smart phones and there are also bar code printing progs. The scanners on checkouts are very good these days and they scan in two directions to get the best signal from anything that looks like a bar code.
  6. Jun 27, 2013 #5
    bar code reading apps for all? No. There are different kinds of barcode readers according different platform, such as Java barcode reader, .NET barcode reader, etc. I know a good barcode solution site. It's called onbarcode. It provides various barcode readers and barcode generators. I have used two tools from there. They are as follows:
    That site is very helpful for barcode creation.
  7. Dec 16, 2013 #6


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    So my Pentax DSLR could be rung up as a packet of frozen peas? We live in hope.
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