Open Source Interface

Build yourself an LCD Projector

2008-11-20T08:18:18-05:00

This may be very useful.... should give better screen resolution and pheraps less expensive than a videoprojector itself.

http://www.funlol.com/9662/Do_It_Yourself:_LCD_Projector.html

IR-passing light diffusers

2008-09-26T21:29:28-05:00

A IR-passing light diffuser would be perfect for a LCD Setup. Light diffusing for backlight, and IR-passing for crystal clear tracking.

Any leads on such a material?

How about the plastic cover they use for motion sensors. It’s white/diffusing and ir passing for the sensor. Any one have any idea what material they use for that?

Do I still need a mirrow if I have a short throw projector?

2008-11-17T16:07:34-05:00

Hello! If I have a short throw projector which could project 21” at two feet, do I still need to use a mirror? Or having a mirror would work better in everything? Thank you.

LCD FTIR - first results

2007-11-23T00:29:52-05:00

here is a screen-shot of the first prototype with an LCD screen and FTIR..... the blobs come out beautiful and easily recognizable.

also; i managed to achieve these results with minimal modification to the LCD screen. The only modifications i made are:
1.) removal of last reflective layer (this is necessary obviously)
2.) adding IR-blocking film to the sides of the interior LCD acrylic. This blocks any stray IR light from the CCFL.

I left the fresnel lense and the diffuser in the LCD and was still able to get crisp and workable blobs. I dont think it is necessary to remove these filters, although some LCD’s may have two fresnels and two diffusers which may attenuate the IR signal.

In the end, I don’t think it is necessary or wise to try create your own back-light. Lining the acrylic with IR blocking film will considerable diminish unwanted IR light.

LCD FTIR - Video, Questions

2008-11-09T21:37:33-05:00

So I converted my Side DI LCD to a FTIR LCD this weekend, and am getting so so results.
Here is a video showing the view from tbeta.

So after being on this forum for months and searching through many forum posts, I still dont think I can find anyone who has created a successful LCD FTIR. Most people using an LCD give up and go with a Side DI (which is what nima I think ended up with) or Rear DI, go with a LLP, or combine these techniques to make up for each design’s possible shortcomings. Or maybe the fact is that people have created them, but havnt posted enough about them for me to remember them.

My setup works, but since there is no compliant layer, it takes a lot of force to create bright enough points to be registered as blobs. Putting a compliant layer on isnt out of the question, but for LCD setups, I dont know if anyone has created a usable compliant layer that is clear enough not to disrupt the LCD image.
My acrylic is about 6mm thick, using 48 (12 on each side) 5mm LEDs, which are pointing straight into the 90 degree sides of the acrylic. Ive seen mention of angling the LEDs or sides of the acrylic:
http://nuigroup.com/?ACT=28&fid=36&aid=48_5C8SbBuWgVIaM7gCANad
http://www.outgribe.com/jason/ftir/ftir.html
But also reports that it isnt necessarily needed (any insight is welcome).

Let me know what you guys think, as I really like the control that my LCD Side DI produced, but wanted to minimize the 5mm or so height that my fingers would get picked up to a contact pickup. If I cant get this figured out, Ill probably tear some CD drives apart and put together an LLP setup....

Backlight woe

2008-11-17T21:12:31-05:00

I was dissasembling the LCD I planned on using for my MT table and accidentally broke the backlight in the proccess. Anyone have any suggestions for alternative backlights?

LLP LCD - front capture

2008-11-14T12:09:46-05:00

Hi all,

Sorry if this has already been discussed (I looked but didn’t find the topic), but has anyone tried to fit laser modules on an LCD screen (in its original housing and not dismantled) and capture the laser matrix with a cam in front of the screen?
Like this:

There is a video on this forum where we see a guy at a sort of official presentation doing a demo with this kind of setup, but it seems that its really not that hard to reproduce:

LLP LCD - front capture

Has anyone already tried it?

This would be excellent to set up quickly a test rig for development.

Greg

Short projector from SANYO

2008-11-12T09:05:51-05:00

Hello guys, this is my first posting.

I just want to give an information about new type of projector.
They call it short Projection from SANYO.

anybody has notice about SANYO PLC-XL51 or PLC-XL50?

Everyone who wants to build serious multitouch table should considering about this product.
No more mirror for projection the image to the table surface.

here is the site:
http://www.sanyo-lcdp.com/english/product/xl51/xl51.html

Regards,

How to?

2008-11-10T16:09:07-05:00

Any one can tell me what method is this?? FTIR?

http://www.spyeglass.com/bp/Lean-Back-1648.aspx
http://www.spyeglass.com/gallery/Touchscreen.aspx

Large Multitouch ready Panel

2008-07-24T16:47:08-05:00

Have you guys seen this?

http://www.joyplux.com.tw/english/product/product2.html

The site claims:

Product 　Serial Number Note
　42” touch frame 　JXTM-M0-42T0-03-01
　32” touch frame 　JXTM-M0-32T0-03-01
　Customized design is available, please contact us for detail

Large scale touch frame:
1. Material: Metal with tempered glass
2. Design for specific brand and model monitor / TV
3. Multi touch function is available
4. Screw installation, good quality and reliability
5. High sensitivity: 100 PPS
6. High accuracy
7. Area button function to make the program design easier
8. Other size is available (26"~60")