DIY Video Projector Part II

[HanClinto]

Sweet! Thanks for the calculation info.

so for an 8.4" diagonal panel, you would have to place the 12deg light source almost 40 inches away (39.96, TBE).

If you wanted to stay closer to the screen... what about using something like this?



Those are available from www.3dlens.com, and for a fairly cheap price too ($2.06 for 1-4 units). With an array of those, you could do something which was proposed a month or so ago in a different forum, and have each lamp illuminate a smaller section of the LCD. Hopefully crossover would eliminate any dark spots.

What's your opinion on that, Rolm?

Thanks alot! Keep up the great work everybody!

--Clint

[Rolm]

<img src="http://www.3dlens.com/media/fresnel_408(large).jpg">

Hmm, interesting. You would still have to use multiple light sources per image lens. If you were looking to cover your LCD with ((I'm guessing on the dimensions here) a 4x3 grid from this multi-lens, and you were shooting to put 4000 lumens on the LCD, then you would need 4000/(4x3) lumens per image lens, or 333.33 lumens each. And then there's overlap as each of the spherical beam's edges touch the image lenses adjoining the one it's aiming at, which means that each beam needs to be run through an apeture first; and then there's the problem of the different beam angles as a result of using multiple LEDs...

Interesting, but I think it would be alot of engineering to get it to work right. And I still think the LEDs are underpowered.

That being said, I have VERY little first-hand experience with hi-output LEDs, so I could be totally wrong on the lumen characteristics (that is, perhaps there is some magical way that LEDs get more bang for the buck).

It would be VERY cool if someone could make it work, though. The coolness factor of these LEDs over ones previously discussed on this BB is that they are already linked up, and they come with a nice 1157 socket attached. Most of the complexity of the previous idea was having to wire all the LEDs up.

[HanClinto]

For anyone interested I moved my rantings about super-bright white LED's over to a new thread. I actually just found some cool stuff in this area, with some neat calculations in it.

Researching LED's as powerful light-source

Keep running the imagination station.

--Clint

[verbose mustafa]

Have you made a good projector using leds? I belive it can be done. When i simply placed my lce screen on the projeciton lens (delta IV), i projected a 5-6 foot imgae using only the lcds built in backlight. Using the same principals as how backlights for lcds are made, i plan to to make a "super powerful backlight." This way I will only have my lcd attached to my projector lens, and no huge box full of lights and fans. I know i sound like a neophite, but i have done many tests and what not with an lcd and delta Iv.

thanks

verbose

[verbose mustafa]

Originally posted by HanClinto
I was very blessed to find a 5" Sharp LQ6NC01 240x720 for around $45 on E-Bay (not including shipping).

If I didn't get that, I would probably go with the small 2" spy-monitor TFT from Hong Kong -- those look really cool. My goal is silent, cool, small, and portable. I want to try and stay away from fresnels if at all possible.

Just out of curiosity, how many LED bulbs do you think I would need? I have a hard time converting from watts to mcd to lumens and all else.

Thanks!

--Clint

read my thread

Verbose Mustafa Project Update

I am also going for the "small DIY pj." I have done it, but i need to modify the backlight somehow... LEDs are my first choice.

[Dnt32]

I am new to this forum and I have built a TV projector which is down now since it was temporary. I was going to build a more permanent one, but since I fell into this forum by mistake I have changed my mind and I will build a LCD projector instead.

First off Im just a bumkin from Alabama hehe but I have smarts. And Im excited now about this LCD projector. As of now I wont be building this Cause IM going to wait until I upgrade my video camera. And use the one I have now for some parts.

Ok now that I have introduced myself I have a ? concerning the letter boxing you guys are doing to your LCD's how and why is white light coming from your projector isnt it letter boxed from your source such as the dvd.

When I dismantle my camera it has features that I may or may not be able to use like backlight and exposure and the connection devices.....but how do I know if the LCD is going to be good enough. I have the spec sheet that came with the user's manual. But I cant get crap froim them.

Doug

[Dnt32]

Wish this whole thin was a password protected chatroom

the wait is awful

lol

[HanClinto]

So let me get this straight... you have a video camera with an LCD on it so that you can see what you're taping, and you want to use that LCD panel for your projector?

Just making sure I've got what you're saying.

Yeah, I feel the same way about waiting for answers.

--Clint

[Dnt32]

Well I was informed in another thread that it wouldnt be feasible to use any of the parts from the camera and just to sell it.
And if this doesnt fit this thread Sorry Im new to this forum.
And besides its all kind of jumbled to me. Wish it was catagorized then maybe subcatagorized.

Or may be a definition of the titles of the threads. Guess I ll come here when i get started on my project but everyone is so far ahead.

[zardoz]

Wellcome! You are'nt too far behind us...my project has suffered numerous delays due to the deploreable courier services, still waiting for my LCD to arrive. I'd make sure you know the camera's res on that panel, I'm guessing it might be low. If it is? I'd have to agree... sell it and use the bucks to get some more appropriate gear.

I do agree, the threads are a bit jumbled, but this sort of "forces" people to read as many as they can stomach in order to keep from asking questions that might be ignored. You've got the bug now so learn all you can before you rip down your cam and maybe waste it.

zardoz