DIY Video Projector

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hey all

thought i'd check in. i got my own setup running using the LCD matrix from a 15 inch flat panel (viewsonic vg150). its powered by a bell and howell 388a, which is a big metal box with one of <a href="http://www.donsbulbs.com/b/i/d/dys.dyv.bhc.html">these</a> bulbs stuffed in it. works pretty damned well. the bulb just burnt out after a particularly long use, and i've already got 12 replacements en route.

i've been working madly on the screen for the system. right now its <i>still</i> just a couple sheets haning down. i've got a huge sheet in the back yard, drenched in double good plus matte goddness ultra bright white paint. spent half a gallon on that one sheet.

it should make for a far better viewscreen. its impressive as is, already capable of being run with a bit of ambient lighting plus a black light and still looking sharp. i'm amazed how much light the thing puts out. but the new screen should be nothing short of a revolution.

i've got serious plans for version 2.0. i need a bigger fresnel though, something big enough so i could mount one of those 1280 x 1024 17 inch lcd panels to it. as is, i'm loosing some of the screenspace of the 1024 x 768 15 inch lcd i'm using, and thats just gotta change. i'd like to use some sort of zoom setup, but i'm not totally confident in my raytracing abilities.

also, the cooling right now needs some work. i'm thinking of taking out two of the standard fans and adding a second squirrel cage fan. with a decent mount job, it'd look a lot better than it does, plus it'd be a helluva lot quieter. just a silent whir in the background.

this is a totally different realm that we've talked about, does anyone know what it'd take to be able to make a small in home buisness out of making these for fun and profit? i couldnt just rip apart viewsonic monitors though (and use them in my prodcut), which is unfortunate (considering how easy it was to do). i still think theres hope of bringing a slightly larger slightly more powerful way cheaper projector to a small market.

waiting for bulbs to arrive. hopefully i can spend this time productively, before i get wrapped up in playing more video games.

Matt
 
Matt

Matt,

Making these for profit kinda breaks the spirit of this whole thing. However, I'm sure my friends will want one, and I don't mind charging a SMALL fee to build em one. :)

Anyway I was thinking of building a few for my family once I got the optics and lighting right. I'm still looking for the right LCD to use too.
Has anyone tried the portable Playstation LCD's ?
I know it was mentioned a few times during this thread, not sure if anyone posted the results yet. They sell NEW for $100.00 here at Toys R Us. The have the AV inputs so all that would be needed is to remove the backing and driver board. I'm also able to resolder if the driver board is in the way.

I think I can get the optics right once I find a suitable LCD. STill waiting for my bid on ebay to finish :)

BTW..Matt, what are you using for your projection lense ? I think that may have something to do with your screen loss.
If you dont get the lcd to center exactly on the lense you WILL loose some of the picture.

Well ill post my results once I get my lcd.

Later
 
Hello again...Even though thoose laptop lcd screens are realy cheap, the bigger lcds (8"->) are cheaper anyway, so going for a bit bigger screen than the <-3" doesn't sound bad. I was also searching for some bright and good looking lamps. Many of thoose Osram lamps seems like a good idea. And the costs are around $30, I've checked it with a lokal dealer. At that prize, running 9000 lumens+ (GX6 lamp, but it all depends of what lamp is selected) it shouldn't be a problem to get thoose big pictures bright enough...or what do you think? By the way, check this LUMEN monster out! :) http://catalog.myosram.com/srvc/z_m...9EE832BE2093E8&load_area=30300200000000000000

if that link doesn't work, go to the product guide www.osram.com and search for E4050300283104. Using this kind of lumens at 63amps should realy bring things bright :) 500.000 LUMENS!! :) This baby must cost a fortune...
 
CHAT ROOM NOW OPEN !

Hey guys,
I just set up a chat room on IRC (mIRC) on dalnet.
If anyone is interested, join the #DIY-LCD-PROJECTOR chat room
using a IRC client. The most common type is mIRC, which can be downloaded at http://www.mirc.com

If you dont know what IRC is, or need help setting up your irc, leave me a msg here, or shoot me an email.

Let's get together and share ideas in a more interactive environment.

I also plan to set up an FSERV to allow us to share pics, video etc. Without the need for webspace.

So come on in, and lets get started. My nick there is Truluv. Drop me a msg if your interested in contributing to the channel.

Leave your forum name if it is diffrent then the nick you will be using.

Thanks,

John
 
by commercial i pretty much meant build them for friends for a small fee. spread the low cost projection goodness.

i cant stress enough how nice it is using a nice big LCD. the lcd is actually a bit bigger than the projection screen, so not all of its used, but a bigger fresnel will fix that. i have the lcd a lego brick width away from the projection surface, so focusing is actually pretty close to how focusing would go normally.

the huge c&h fresnel looks really tempting. you'd most likely end up cutting some of it off but $89 isnt that much too pay for a fresnel. better than the uber-ripoff of edmun scientific which wants to charge like $300. just think of how nice a system you'd ahve with a whole 18.1 inch 1600x1200 LCD matrix in it. smooth as silk.

oh, and one thing to consider is that the closer you can put the bulb to the fresnel (can be done with ?greater? focal length?) and still have the optics work out, the more light your collecting simply by inverse square law. of course, i think you also loose optical quality. i'm going to guess projectors are probably some place around the sweet spot, and run with it from there.

i'd like to setup my basement to produce $1000 projectors running 1600x1200 using the DYS/DYV/BHC bulbs. I'm thinking of using a custom metal frame with squirrel cage fans for cooling (hunting for good source online for squirrel cages). it'd be kinda nice to setup a block that i could mass-weld frames on for future use, and then just assemble everything. and on the plus side, all you'd have to do is throw in a $250 15 inch 1024 x 768 matrix instead of a $900 18.1 inch 1600x1200 resolution matrix to drop the costs, with only the loss in resolution for a price.

version 2.0 is gonna have the optical systems mounted on a one dimensional slide system with automated stepper motors controlling the positioning. i'd like to figure out how zoom lenses work and to get this rangefinding system working, which would let me pretty much enter a screen size in software and have the automated microcontroller adjust the optics to relative perfection. no clue how the zoom lenses work though. sigh. might just have to deal with autofocus. need to find a good book and work on a zoom lense setup though.

unfortunately, i left the docs for my current automation hardware at my dorm. i havent started the firmware for version 2.0 - and cant really start it - until i get back to my dorm next saturday.

trying to get my pictures developed and scanned. will have photos soon. might have to setup a geocities account. *shiver*

oh, and watch your heat levels everyone. the lcd matrix's usually are only rated for operating temps of 104 F, with storage tempts climbing into 140 F range.
 
oh, yeah.

we got snow, and it snowed all over the screen i had just painted in the back yard. its sitting in the living room on a giant canvas right now. not sure what my plans are right now, its gotta move by tomorrow night or inventing privledges might get cut off for a bit. :D ;) :D

the thing was looking great though. its just a pretty thick sheet painted in about half a gallon of extra-flat extra-bright acrylic paint. was going to be one of three sheets comprising the screen, which will be carpet taped to the wall.

i have a backup projector i'm using now. its pretty weak, nothing compared to the 600 watt monster i've been enjoying so much.
 
i was just cruising around looking for inspiration. i got some.

dream matrix:
sgi 1600sw

man, 1600 x 1024 with a nice 350:1 contrast ratio. i'd love to try out this natively widescreen puppy. now i've got to try to convince someone to have me build it for them. i cant wait to see how nice this will look.

something weird with the interfacing though. looks like it uses laptop style lcd interface, and expects you to get an extra $400 adapter. probably more effective to get one of the high res 1600x1200 ibm flat screens.



anyways, optics work never ceases. trying to get a more complete image of version 2.0 in my head.
 
alright, last post, i promise.

my screen finally finished drying. its a bit water damaged and needs a good repaint already, but its already far better than a plain ole sheet i've been using. even this shiza backup projector i'm getting a decent image now.

also, the problem where the darks washing out seems to have alleviated itself. with half new screen, half old screen, the dark scenes wash out horribly on the old screen but turn crystal clear on the new screen. very sharp, very crisp. much better. the difference is really like night and day.

i'm going to have to rewatch and replay my collection now and once i get my new bulbs.
 
I'm with you.

Hello,

I'm a young electronics engineer from Turkey. I just wondered if there any people plan to build home made TV projectors at internet and I found this forum. Because I plan to make my own projector too...

I'm working at our national electronics and cyriptology research institute's Optoelectronics Lab. My job is designing digital
imaging systems (digital cameras), general electronics design
and software/firmware development.
I'm also in my master education. I study linear optics,lasers
microprocessors and semiconductors.

I can find most off required equipment. And I downloaded
all of 30 pages of this forum. :) I don't have much spare time
but I'll start to work about this fantastic idea.

I think using color LCD screens with amplified homogenous
light is the most realistic idea. Is it fast enough?

And is there any working project prototype photos like
http://home.bluemarble.net/~lewellyn/html/prototype.html ?
I mean pictures of both projector system and image on the screen.

Regards...
 
Off-axis projection

Optics gurus,

Any clues on how to do off-axis projection? I like the short throw of the delta-20 lens and would prefer to run the projector in front of the viewers to keep the fan noise away. I believe off-axis projection will enable me to place the projector without blocking anyone's view; keystone correction will probably be accomplished with software.
 
Re: Type-E

zark said:
I'm going to order another LCD at the first of the month. I put some more pics that show the LOA in the box. Also I purchased another LOA. Thinking of running two.

Going by the 10% rule I should have 820 lumen with one and around 1600 lumen with two.

I just looked at your new pics, would putting alumimum foil around interior of box enhance the light out to through the projector lens?
 
putting tin foil inside your case will cause more light to come out. unfortunately, its in no way really useful.

if you look at an overhead projector, all the light goes directly from the projection surface to the overhead optics system. with tinfoil, there would be more light coming out of the projeciton surface, but it'd be aimed in psuedo-random directions, and therefore not useful.
 
Myren

I would agree if I were using an ohp or had a longer length between the LCD and the lens, but my LCD is nearly touching the lens so I shouldn't waste much light. The lens is also pretty big which makes it a little harder to fill with light. Just a thought. I'll have to try it out and report the results.
 
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