DIY Video Projector

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Sucess! (sorta')

Ok, so I have had crappy luck with the lenses I have been using. I decided to try, just for the heck of it, my little old projector lens from my $17.00 opaque art tracer. I couldn't believe how clear it was, and how nice the picture was all the way across. I haven't had good luck with the led's, so I am thinking of getting some cheap flashlights, and mounting the bulbs and reflectors in with my p.s. and bouncing them off of a mirror. I will post a new pic of what my new setup is. Hopefully, I can have it done by the end of the weekend.
 
UPDATE

I have scanned through quite a few pages on this message board. I am pleased that some of you are taking the bull by the horns and giving this project you best effort. I have been wanting to build a projector like this myself. I would like to read a condensed version of how close we are to getting some quality results. It appears that Vince is very close. What hurtles are you not able to get over Vince? It also appears that some of the people posting are going different routes. That is good and bad. Good because if one route fails another may provail. Bad because there are not enough people experimenting with the same equipment to brainstorm their way to perfection. I believe that the white led idea has very promising results. Ideally the finished product will have to be relatively small in size, and not to have to be so far away from the screen that it would be impossible to use it in a small living room or bedroom. Sometimes the best way to get ideas is to look at the project from different angles. Usually inventions are the product of two or more ideas mixed together. Maybe try imagining the end results you wish to obtain and working backwards. In other words, look more into the ones on the marketthat do work, study them in extreme detail, and add or mix in other ideas to make it even better. Is there no source out there where a guy can buy the same optics that are used in the lcd projectors on the market, and get them at a decent price? I don't see that there are too many electronics based hurtles. Can we not find the lcd's that are being used in the projectors that are being used by corporations to market their products? Ok I'm not trying to be a bad link in the chain here, I just think there are alot of people spending alot of cash, and so much time, and not getting the results they want. What do we need to do to get one of these tech guys with all the answers to post here. Do we have to start pestering some of these troubleshooting sights by email to get some answers? Maybe we need to give them ideas on how they can make money off of us by putting together some type of home builders kit that they can market by infomercial. If they were selling the kits by the thousands, they could buy parts from suppliers in bulk at a reasonable cost. Anyway, I don't need something that is going to be as bright as my television screen during the day. Sure that would be nice, but I would settle for bright enough in nighttime to watch comfortably without painting all my walls black. So it would need to be bright enough in dim lights like you have at the movie theater. Don't want to hinder, just want to help. Please update us Vince on what your most recent parts are and your results. That way we wont have to keep scrolling back to get info. If you can add the most helpful web links to find the parts, it would help alot. Thank you CHANCE
 
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Looks like dwalls32 is leading the pack as far as completing is concerned.

The LEDs seem to be an idea for the future. But, I'm starting to move away from it for now. I don't think the engineers who are developing white LEDs will stop until they've developed the ultimate white LED. Sometime soon, we'll see some improvement on this technology. It's only been out about 2 years.

As for me, I started grad school on Monday. My time is even more tided up now. I haven't been able to research lenses enough. dwalls32's new discovery will probably help to move thing along faster now.

LN, I have no new parts right now. Mine were like dwalls32, but the config was different. I was putting it together in a modular config, e.i., from back to front- light source, small fresnel, large fresnel, LCD, plano-convex lense, projector lense. The box was slotted to be able to move parts back and forth. My config didn't work, but it has promise.

My parts cost about $300, but would have been less if I went with the halogan light source. But in the end would have cost more for replacements....so...go with what works!

Anyway, I'm happy to see someone made progress. It's not an easy project for alot of reasons. If you took it on, you kow what I mean!

Good luck! Keep it going!

Vince




[Edited by vdi_nenna on 10-27-2001 at 08:37 PM]
 
I woud guestimate I have spent about $210 dollars on parts, and I still need to spend proabably another $50 to finish. This includes a better light source and a case to hold it all and replace the cardboard box it lives in right now. The majority of my money went into an LCD panel that had SVGA and RCA inputs, an nView Z115. As far as lens size, I would say around 50 mm. I took it off of an old opaque projector anyone could pick up for 20 bucks at an arts and crafts store (sorry I couldnt find a picture, I'll try to post one this week). The whole picture does fit, however the sides are very dim due to the light source I am using. I'm using a high powered flashlight to test since, as Vince said, the led's are a problem. They are bright, but they just don't cut through that lcd panel well enough (yet).

[Edited by dwalls32 on 10-27-2001 at 09:27 PM]
 
YEah, I need to borrow the digital camera from work this week, then I can post some. I am still working to find a suitable light source, so the pics of the screen will be dim. I would say the projected image is around 11 feet across. Does anybody out there know the CHEAPEST place to get cold mirrors? Do you guys think gluing a heatsink to the back of a standard mirror would absorb heat? Thanks

[Edited by dwalls32 on 10-28-2001 at 02:59 PM]
 
I used 3d studio max to do the 3d stuff. I took those at about 11 last night. The problem is that I am using a digital camera from work, and you can't turn the flash off. I will try to take some real film ones this week. I did double check to make sure all edges were visible, and they are so woo hoo, just need some brighter light...
 
Yes actually. I have watched tidbits of dvd's to test and like having Captian Picards head 4 foot tall. It looks nice so especially for being so big. You're right Vince, the screen door effect isn't bad. I just need a brighter light, it's still very dark with the test flashlight I am using. I did borrow a halogen 1,000,000 candle boat light to test tonight. I should be able to do a better test then.
 
I'm thinking of building my own setup, but I'm considering using an commercial LCD screen. You can get 15 inch ViewSonic LCD screens for $175 if you shop around on ebay long enough. 350:1 contrast ratio. 1024x768.

My one concern is whether or not I'll be able to remove all the excess crap from behind the LCD itself. Of course, I realize its all mandatory, but can I move it out of the way of the LCD itself. And can I remove the backlight?

In short, will I be able to move that stuff out of my way, or am I going to end up with a $175 piece of equipment I could care less for?

Cant wait to play Armored Core 2 on a 10 foot tall wall again. Its been too long.

Thanks
Myren

[Edited by Myren on 10-30-2001 at 05:57 PM]
 
Should cold mirrors and ample fan-age be sufficient to prevent the LCD from byting the dust, or should we begin investing in more drastic measures for heat reduction?

There must be some way to filter out the infared parts of the light. Just like any other colored filter, I'm sure theres got to be some way to do it.

Start peltier cooling the mirrors. I can finally use some of those heatsinks I keep getting.

The other thought I had was overhead projectors. Wouldnt it be possible to go buy a 3m projector (like <a href="http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1653608356">this</a>)? $50 for 2800 lumens, designed for constant daily classroom usage (tolerable lamp life). heat dissipation mechanisms to keep screen from getting to hot. Really, this sounds like the perfect solution, if you dont mind the size. Just throw a stripped apart LCD monitor on top of it and have a nice day.

Also, is it heat alone that damages the LCD? Is the raw amount of light itself a problem? Is there something innately conflicting about having a really ******* bright bulb and a LCD?

[Edited by Myren on 10-30-2001 at 06:29 PM]
 
Test results

Well, I used to halogen flood, and did some distance testing. Seems that the image runs about 1 foot wider then the distance, so when I was 4 feet from the wall, it was approx. 5 foot wide. The sweet spot was around 8 feet. But it focused nicely for all distances. I still need another light, however. It's still not filling the whole panel.
 
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