The end of focus problems?

Machine vision is too difficult. If vendors want to grow the market it has to be easier to install cameras on a production line. So kudos to Cognex for introducing a liquid lens.
A liquid lens is a little bubble of oil and water that changes shape in response to an electric signal. The result is a lens with an adjustable focal length. Cognex have incorporated this into the Dataman 200 fixed mount code reader. I saw it in action on the RR Floody stand at the Vision & Robots show, and I have to tell you that I was very impressed.

What Cognex have done is to combine the liquid lens with a focus-check algorithm and provide a feedback signal. This enables the Dataman to refocus almost instantaneously on targets at different distances from the sensor. In a production environment – say on a packaging or shipping conveyor – the sensor can cope with a range of working distances; there’s no need to refocus a lens every time the package size changes.

I’m sure there are downsides. For example, I would question the durability of the lens under constantly changing working distances. But if you just need the occasional refocus this device takes care of that for you.

It’s my guess that this technology will rolled out to the Checker range before the end of the year, where its impact will be huge. No more fiddling with that awkward lens or worse still, changing lenses. Just aim the sensor and let it do the rest. Brilliant!