Generating an infrared plane

I am trying to find a way to generate an infrared plane that is parallel to a table-top and a few millimeters above the table top. When an object crosses the plane I want to be able to sense where in the plane this occurred. I have been looking at some infrared diodes and transistors, but I haven't been able to find anything specific enough for my application. Does anyone know of a way that I could make this possible, or would I have to have some custom optics built?

Thanks

Some touch screens for kiosks work in exactly this fashion so that might be a starting point.

What do you need? This company makes some very narrow focused IR LEDs that work up to a couple meters (if I remember right).
https://www.clairex.com/

Products->IREDs->Point Source Emitters->CLE331 or CLE333 which are 1~5 degrees beam widths. The narrower of the two is only 0.35mW though. The slightly wider one is 2mW.

They probably also have suitable narrow view receivers as well.

Are these the type you're thinking of?

**broken link removed**

I am looking for a way to do the same basic thing, but I want to do it without the hassle of having a big screen covering the tabletop. I want it to be very versatile and portable. The following link is a project similar to what I'm trying to do.
**broken link removed**

Products->IREDs->Point Source Emitters->CLE331 or CLE333 which are 1~5 degrees beam widths. The narrower of the two is only 0.35mW though. The slightly wider one is 2mW.

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This is a good idea. The way i was thinking of earlier was more of an "analog" solution I guess, where I would be generating a single plane. The way you've suggested is more "digital" and would probably be easier to implement and would be more reliable. It might be a pain to do somehting like an entire keyboard or something like a board game using this principle though since it could mean using quite a few of these

**broken link removed** or this https://www.mcselec.com/index.php?option=com_content&task=view&id=136&Itemid=57 would be more likely

Incidentally, it's probably a good idea if you limit the field-of-view of the IR sensors as well. Either use a lens, or better yet if the emitters are sufficiently bright, just have an aperture a good distance in front of the sensor. If you have a 1-2 mm hole a cm or two in front of the sensor, lined up with the emitter, you'll have a really well defined sensing 'beam'.

If you want an 'analog' solution, you might be able to find a linear PSD(position sensitive diode - it's a large photodiode with multiple taps, google it) and adapt a scanner optics assembly. The digital version is to just *use* the scanner, complete with CCD sensor and use a pair of them as the sensors.

James

you might be able to find a linear PSD(position sensitive diode - it's a large photodiode with multiple taps, google it)

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Do you know of any specific manufacturers. I did a search on it and found lots of academic papers describing projects that used them and a couple manufacturers, but they were all fairly big - around 60mm x 60mm. Do you know if they come in a smaller package than that?

I remember these guys
**broken link removed**
being one of the bigger suppliers. I don't remember any other ones though.

Incidentally, these guys http://www.taosinc.com/ make small 128 pixel linear CCD sensors.

James