Tabletop Multi-Touch surfaces

[charlesshoults]

I found an article on MaximumPC, giving detailed directions on how they made a touch-sensitive table out of a 24x30 sheet of acrylic, a projector and a PS3 camera. Has anyone here tried something like this?

http://www.maximumpc.com/article/features/maximum_pc_builds_a_multitouch_surface_computer?page=0,0

It looks like a pretty cool project, except that it sounds like the device may need to be recalibrated depending on ambient conditions, which could be a pain. But, if it works, it works. I would love to have something like this, but daytime visible:

 

[daveswantek]

Wow; that brings new meaning to the term desktop gaming. Something like this could give rise to some interesting games, or how about a coffee table with virtual magazines including MaximumPC of course.

Dave

 

[charlesshoults]

If you had the money to do one or the other, would you spend the time, energy and money to build a table like this, or buy a large-format touch screen LCD monitor?

The article states they spend about $40 on LEDs, $25 - $30 on acrylic (internet cost), maybe $10 on vellum, $35 for the camera, $13 for the mirror and filter, and the cost of the cabinet materials. They borrowed a projector for the project, but a good reliable and quiet projector might run $1000. Total might be $1200 or more and the finished product might be the size of a medium-sized freezer.

Samsung has a 32" touch screen, 320TSN2, for about $2500, which presumably produces less heat than a projector, and is only 4.5" thick.

If you could afford to do either one, which would you do?

 

[daveswantek]

I would always go with a proven solution over experimenting, especially when it gets over a grand. Plus the samsung would come with a warrantee and could be returned if it does not meet your needs.

My 2 cents anyway

Dave

 

[kllrnohj]

If you had the money to do one or the other, would you spend the time, energy and money to build a table like this, or buy a large-format touch screen LCD monitor?

The article states they spend about $40 on LEDs, $25 - $30 on acrylic (internet cost), maybe $10 on vellum, $35 for the camera, $13 for the mirror and filter, and the cost of the cabinet materials. They borrowed a projector for the project, but a good reliable and quiet projector might run $1000. Total might be $1200 or more and the finished product might be the size of a medium-sized freezer.

Samsung has a 32" touch screen, 320TSN2, for about $2500, which presumably produces less heat than a projector, and is only 4.5" thick.

If you could afford to do either one, which would you do?

That is still more than 2x the cost, and the projector could always be used as just that - a projector. You could also go the DIY route for the projector as well. I totally want to build one of these now. I'm thinking a coffee table housing an HTPC - that would be sweet.

 

[charlesshoults]

One of my coworkers has a 30" Apple Cinema display on her desk. I look at it and think "That would be a big enough touch surface, and the Samsung is only 4.5" thick. ". Then I think about the $2500 price tag of the Samsung, and look at the directions for building the surface. Making the acrylic touch screen and camera setup would be easy, and not expensive. A 1080p projector would be really nice, but if a throw distance of under 3' could be achieved, a 1280x800 projector would be nice too.

http://www.newegg.com/Product/Produ...oogle-_-Projectors-_-Epson+America-_-24157073

While $900 is a substantial purchase, it's not unreasonable. But a DIY projector is compelling. If something like that could be made for a couple hundred dollars, that might be worth trying, even if the LCD does melt in the process.

This makes a basic projector look REALLY easy. Assuming one has access to an old high school overhead projector.
http://www.youtube.com/watch?v=n6n6jW0XIV0

 

[charlesshoults]

Old LCD panels are easy to come by. I have an old Dell that I put together from a pair of monitors my company was going to throw away. It's bleeding some pixels, but overall it's usable. Out of it's housing, it could server one of several purposes.

 

[charlesshoults]

There is so much that an LCD isn't made of, that it's almost ridiculous. The E172FPb that I took apart is an LCD panel produced by LG for Dell. The insides of it look like most any other LCD panel I've taken apart. The glass LCD is black tinted, and only about as thick as a piece of poster board. Behind it are three pieces of film, one kind of prismatic and behind those, a piece of acrylic about 1/4" thick, backed with bright white paper. One cathode tube runs along the top and another along the bottom. I discovered that if the monitor is turned on without one of them plugged in, the one that is plugged in, will light up for a split second, then go out. With both plugged in, they both come on and stay on. And, what's most important, it still works. These pictures were taken with just the lower cathode in place, without a camera flash. I have a 23" Apple Cinema display at work that was taken out by a power flicker. I might just take it home, take it apart and see if i can resurrect it. That would make a rather large, kick butt projector.

My roommate wants a game projector too, so that's two reasons to take on a project build. As Dave said above, something like this is kind of a gamble as to whether it will work or not. A retail solution is a more solid bet. I could always put the cabinet and screen together, then take it to work and set it up on a projector to see how well it works. It would drive some of my coworkers nuts.

 

[charlesshoults]

I sorted through works disposal bin yesterday and came up with six monitors. Two of them are the same model as my current 'spare' monitor that I use for servers and such. One of those, apparently got hot enough to melt plastic, so that was the first one I took apart. Apparently, it's power supply failed, taking out a couple capacitors. The monitor still turns on, giving the RGB box bouncing around the screen, but as soon as a VGA cable is plugged into it, it goes into sleep mode. I'm going to pull the LCD panel to eliminate the 'bleeding pixel' issue that mine has. The other monitor has either a dead cathode tube or cathode controller on it's power supply. It's either an easy fix or a lost cause. Two monitors have a slightly smaller cabinet size, but less of a bezel, so might still be classified as 17" models. One of those has a 4-port USB hub and built-in speakers. It has two inputs, one for DVI and one for VGA. The VGA input appears to be dead, while DVI still works fine. The other monitor is just a plain monitor with no added features, VGA input. Of the last two, one is a rather bulky gray 17" LCD. I didn't pay attention to it's make and model, but I can't find anything wrong with it. When I plug it in and turn it on, it seems to work. Only thing I can figure is it's either an image quality issue or something that shows up over time. And the final monitor is a 20" Apple Cinema Display. This is the one I'm most interested in. 1680x1050 will make either a really nice projector panel or if I can fix it, replace my 19" BenQ. My 19" has the issue where one of it's inputs died, except that it was the DVI connector that went out, leaving only VGA working. I won't be sad to see it go.

I also might have access to a dead 20" iMac. The system had one externally-accessible memory slot, with one built directly into the logic board, but it was the integrated memory that went bad. The rest of it is fine.

I'm going to order an overhead projector, somewhere around 360w, transferring its guts to a wooden cabinet, seeing if I can get it to work with 17" and larger LCDs. A 15"x12" fresnel would cost me $28, while one big enough to handle a 1080p monitor would be about $120. Not sure if I want to spend that much. If I manage to get a smaller one working, capable of pushing 720p, I might make a larger one later. I read articles about people making projectors using arrays of white LEDs. These might produce less heat and be a little more compact, but spending 20 cents each for 960+ LEDs is not a cheap option.

 

[charlesshoults]

When I got home from work last night, I ran a test on my oldest LCD panel. I used the one with bleeding pixels as I have two other monitors of the same model. I did some reading about the anti-glare surface on the front of the LCD. These are basically clear pieces of plastic with a matte finish, applied kind of like window film. Some state that this stuff is easy to remove while other say it's extremely difficult. I set a microfiber cloth on the screen, then a towel on top of that. I then began pouring water over the towel. It held almost four cups of water before I started to see seepage, so I let it sit in that state for almost four hours before trying to peel it off. No dice. I let it sit overnight and tried it again this morning. Once I got a corner up, it was really easy to remove, and makes a BIG difference, both in reflectivity and light transmittance. I held both screens up at my computer monitors across the room and while both are fuzzy at that distance, the altered screen is much clearer.