Light curtain arrays


Thread Starter


Hello everyone,
I'm working on an application that requires the accurate measurement of a cube of bricks as the cube is being built. I'm thinking about using a light curtain array to determine the top of the last layer stacked. The scanner would interface with a plc that would supply a robot with a set-point for the next layer. I'm not at all sure about what type of signal I would need from this system, but I'm thinking along the lines of some type of analog.

Now, to the point of this post. Who are some of the manufactures of light curtain scanners. What type of interface would work between the scanning system and the plc? Any idea of the cost?

Thanks to all who take the time to read this.


Lyndon Chatman

I have had a few projects in the past that required aa light array measurement system.

Two types of measurement systems readily come to mind: Banner "A-Gage" High-Resolution Mini-Array, and "Scan-A-Line" which gives good accuracy, but requires calibration using a exact measured sample.

Both systems provide an analog signal for your use.


Banner makes an excellent line of light curtain arrays that I have used in the past with GMFanuc (now just Fanuc) robots for very similar applications (stacking boxes instead of bricks).

The light curtain output would send a 4-20mA signal out that you could read and scale to determine the height.

Note that light curtain arrays are priced based on how tall of one that you need. Depending on the size of your cube to be built, and what sort of environment, mounting options, etc, you might want to consider an ultra-sonic sensor mounted overhead. This can typically be done for less cost, and still give you the accuracy that it sounds like you would need. Banner makes these as well.

I have no vested interest in Banner, I simply use them wherever I can and have never been disappointed by their performance.

Hope this helps!

--Joe Jansen

Zoltán Mezzõ

Hello Jeff,
I have had some works on light courtain applications, and have 2 ideas on your problem:
1: "diSoric GmbH" : a 1st class german firm, working at this sensors ("": )
2: I decided to use individually developed laser measuring device: low proce, high accurrancy, and you can find an university or research institute to develope it...

Good luck
Zoltán Mezzõ