Wednesday, November 12, 2008

Making and reading data matrix codes

A sizeable part of the machine vision industry is devoted to the reading of data matrix codes. Those are the little checkerboard squares that are turning up on more and more components. They’re like bar codes only they can convey much more data, which makes them useful for part traceability.

Now while it’s true that the machine vision engineer doesn’t need to know how the marks are created, I happen to believe that a little knowledge can’t hurt, and that’s why I’d like to share with you this article from “
Industrial Laser Solutions” on “Direct Part Marking.”

There are several ways to apply the codes – ink jet, pad printing and so on – but this article focuses on laser marking. What’s particularly interesting, (or alarming, I guess it depends on your point of view,) is just how small the individual data cells can be. As vision professionals we should give some thought to what that means for resolution, field-of-view, and locating the mark in an image.

Don’t let anyone tell you that reading codes is an easy vision application!

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