Homebrewed LCD Projectors

pseudofrog writes: "Seems the new thing to do may be to build your own LCD projector. For a couple hundred bucks, some guys are making projectors similar to the professional ones that cost thousands. And it looks pretty simple, too."

Cost of the bulbs?

Er.. I thought the bulbs alone that powered the projectors cost several hundred dollars? Unless the manufacturers ridiculously over charge for the bulbs, I don't see how an entire system that costs several hundred dollars could compare to a system in which the bulb alone cost that much.

Simple?

Well everything looks simple.

LCD/oLEDs

The coolest part about all of this is that in a few years time, the technology will be there so that the walls of your room are LCD/oLEDs and with the touch of a button you can make your walls have any wallpaper you want.

Just think, you could have the Windows "Clouds" wallpaper all over your room! Imagine that! Gee, if that were my wallpaper, I know I'd feel like I was actually in the clouds.

Hargun

Re:LCD/oLEDs

Just think, you could have the Windows "Clouds" wallpaper all over your room! Imagine that! Gee, if that were my wallpaper, I know I'd feel like I was actually in the clouds.

Really? If I had the Windows "Clouds" wallpaper all over my room, I'd feel like I was in Hell!

Moderation Totals: Flamebait=1, Troll=1, Total=2.

Woohoo!

Now everyone can have a fairly affordable 50+ inch flatscreen display, for a truely awesome gaming experience!!!

well if its dark in the room and you have enough windowless wall space anyway and enough room to put the projector and .. and.... Well on second thought, back to the drawing board

Cool projection?

Combine these projection systems with white LED's [slashdot.org] and we might have somthing here! =)

Already slashdotted.

I guess they should also build a server to go with that LCD projector, just for such an occasion.

/.ed Already

It seems as though it is down already so here is the google cache [216.239.35.100]

Mmm

No picture of image result....that suck.

Is this another 50 feet Giant TV like project.
Without seeing the end result I won't spend money trying it.

Reasons for Skepticism

Interesting. Now is this confined to hobbyists because the LCD companies are too slow-moving to have thought of it first? Or is the whole idea fundamentally flawed?

What I'd really want to see in the article is: Joe Blow built his own LCD projector for $350, and the image quality is better than what a good projection-screen television delivers.

Instead, there are lots of plans from hobbyists making their own, but no clear word about whether even the best of these designs produces an acceptable image.

One key thing: most of these designs call for a miniature 800x600 LCD monitor. Once projected onto a wall, how does that compare to the dots per inch of a regular projection TV? I bet it doesn't compare favorably at all.

The big question I came away with after reading this is: why aren't the big LCD companies developing this kind of product? Maybe it's an idea that, even with big-budget R&D, won't produce an acceptably good image.

Re:Reasons for Skepticism

In fact, the image quality on these systems can be much better than your typical projection television. I have a system such as follows:

• Book sided pc with a Celeron 566/128mb, integrated sound (mostly left over parts+$75 for the case)
• Generic BT848 tv tuner ($50 CompUsa)
• Dukane 4000 lumen projector (ebay $100)
• Active matrix Nview projector panel capable of 1024x786 native resolution ($200)

Total $425

I also got a 72" wide screen for $75 retail, but a flat white wall will do almost as well.

The quality on the system with DScaler is very impressive at 1024x768. The only difference in parts between what I have an the author of the linked site is that I've not tried putting it all in a box. Currently it all sites on an end table next to my couch and projects onto a screen which hangs down from rafters. I see no reason why putting in a box would make a difference in the quality. It would probably make it better by blocking out extraneous light that escapes from the overhead projector.

Now while the quality is excellent (you have to play with the brightness/contrast to get a good picture), there are quite a few drawbacks that don't have to do with image quality:

• It get's damn hot. A 4000 lumen overhead projector bulb will heat up a small room pretty quickly. Fortunately I have very high ceilings (the screen hangs off rafters) so it's not too much of a problem
• The fan in the overhead can be pretty loud, but I only use the projector for DVDs, and the volume of the movie is usually set pretty high.
• The bulbs only last 75-100 hours. They only cost about $7 each (less in bulk), and my projector has a backup bulb replacement switch so it's rarely an inconvenience. The current halogen bulbs for stand alone projectors typically last 2000+ hours.
• It's pretty ugly. After all it is an overhead projector on an end table, so it looks very out of place in a living room.

My setup could use a little more CPU power. A better graphic card would be good too 'cause I had to settle on a Geforce 2 MX 200 because it was the best half height video card I could find. Also a sound card with a dolby decoder would make it even better.

It does work, 'though, and looks great, but as you can see it's not perfect.

-dameron

Could this have helped save some dotcoms?

A lot of dotcoms did digital projections for their clients... and if we use my company as a comparison, they could have saved $12,700 if they could have had two projectors for $300.

Now, they only had two projectors... imagine how many some of the bigger dotcoms must have had, and how much money could have been saved had this been out earlier! ;)

Google Cache Link

Build Your Own LCD Video Projector [216.239.33.100]

zerg

"And it looks pretty simple, too"

By simple are we talking about some of our fellow slashdotters hook the rest of us up, or are we talking simple for millionaire phds.

Almost did the same thing

I bought a panel projector from a junk dealer for 10$. This is an older model, 3M 6150, so it's TFT 640x480 18 bit color.
Then I bought a smashed laptop screen for 5$ to get the backlight out.
Put the two together and I got a 15$ LCD monitor, this is fine for messing around with older gear like the Commodore 64, or a PC in 800x600, which the LCD panel can scale.
I'm pretty happy.

CAUTION: Raw LCD panels are very sensitive to static discharge! Use a wrist strap.

How Dissapointing...

Here I thought the headline was "Homebrewed LSD Projections"... having to do with homemade LSD visions.

Google cache

See this page cached@google [216.239.51.100] :)

My house

Great, now how do I install one of these for each wall in my house, and get a customised version quake where I can go running from room to room before getting zapped by a bouncing eyeball...?

Mirror Here

http://meshier.com/mirrors/www.audiovisualizers.co m/madlab/lcd_proj.htm [meshier.com]

Another link

Just in case the main site gets /.'ed, It basicly involves a powerful bulb being sent through a LCD. He is using 2 fresnels to help get rid of some of the distortion, but I'll belive the quality when I see it.

A link from the main site: DIY LCD Projector [rr.com]

BTW...My office just picked up a NICE LCD thingy. It has 4 video inputs, 2 computer inputs (displayed PIP-style or side-by-side), and a 100mbps ethernet switch. We paid close to $10k. In my opinion, it was worth every penny. I'd rather spend $10k on something worth it than $500~~$1000 on something not worth it.

diyaudio.com

A nice thread on DIY projectors, a lot of them are done with LCDs.

diyAudio [diyaudio.com]

Dunno..

The sites seem to mention the results (when they succeeded) were kinda pixelated. Others have pointed out that the bulbs they use tend to have a short life. With an image of the projected image it may be able to make a better judgement. How does it compare to the lower end projects that cost about 1700 or so?

As a side note, I'm looking at setting up my home theater to proper levels, and if these projectors display a good image, they seem to be a much more viable solution. Any one have suggestions regarding this? It seems that getting a 1000 lumens projecjtor that can do up to 720p isn't too unreasonable compared to any CRT or projection based TV solution. Is 1000 lumens sufficient? I'm specifically looking at the Mitsubishi SL1U Projector. I'm aware that watching TV/movies with such a system will naturally require a low level of ambient light, but two things are very cool about this.

1) Pretty much as big a screen as I want, provided distance in the room. Speaking of which, how far back is needed to get, say, a 60-70" image? Again, having seating so as not to get in the way of the projector is another issu...

2) When I move, large TVs are so unmanagable. The projector, and possibly a screen (maybe just use a white wall, provided the wall is smooth and white enough) Projector is on the order of 6-10 pounds, and the screen would be also manageable..

Who all has experience with this? My current rig is an old 24" console TV from the 80s with gaussed spots all over and annoyingly cropped image, so it wouldn't take much to impress me.

other than hack value.... why?

You can get 800X600 lcd projectors on ebay for less than $500.00
and these dont need a computer, just plug in composite video.. (I can hear it now the videophiles that have their 2048p projectors that use fiberoptic digital video and HDTV ready HD-DVD players will whine that it's grainey,low light because it's lower than 95,000 lumens and doesnt have glass lenses made by Plossol in germany... Go to hell videophiles..)

The dayton hamfest is coming up very soon, you can get a (GASP) old technology video-tube projection tv for probably less than $300.00 that works fine. (granted, it's a coffee table, but hey...)

the golden rule is that you scroung for a used one first, then look for cheap new, and THEN create it by hand.

DIY discussion

diyaudio [diyaudio.com] has a 100+ page discussion of this. Most people are using an overhead projector with their standard lightsources, or mercury vapor or metal halide bulbs. The OHP's fresnel lenses get around the problem of having an LCD panel and lens with different sizes and not wasting a lot of the light(but they're kinda big). Pretty good results have been obtained. However, there are some caveats, the contrast ratio of lcd panels from desktop monitors are pretty poor(under 300:1), decent commercial projectors have contrast ratios > 1000:1. Although I haven't built one yet, I think this can lead to washed out images. Also, nobody has found a supplier for the nice 1-2 inch LCD's used in commercial projectors

Does it work really?

My main interest is playing movies on the wall of my living room.

This project looks nice if I can find someone to do it for me that is.

I have a few concerns though.
1) Aren't dvd players using Macrovision to forbid a signal to be output on anything else than a TV? The signal going to a video capture card seems to be a slight problem. Is this a reason why every one in the article is talking about LD and VCD, these two older media not suffering of the Macrovision "virus", er copy protection.
2) Is this really cheap? I mean a dedicated P800 in the living room (cpu speed to cope with descaler complex algorithm)+capture card+LCD panel, etc... I don't even mention the electric bill.
3) Noise level: Getting a Pentium noisy as an air carrier next to a TV and adding the noise of the fan(s) for cooling down the bulb(s), does that meant that I will need to listen to the movie with a pair a noise cancelling headphones?
4) Space: I imagine that the distance from the projector to the screen needs to be consequent. I can't find data regarding the minimum size of a room to use the projector.

I still like the idea though.

PPA, the girl next door.

Make it even cheaper

I don't know where the first component could be found, but I could probably make a working model for around $200...

1: 6mmx7mm LCD screen (don't know if they can be made that small with decent resolution for a reasonable price)

2: Beseler 67 Photo enlarger

3: Bank of 4-8 halogen lights (or a single car headlight?)

4: Maybe a lens to focus the bank of lights

The correct wiring and such to make all of it work. The Beseler will already have the correct lens for focusing a screen of that size, and if you replace the standard enlarger lamp with something like a couple of car headlamps or something, you can probably squeeze out enough light (with a lot of life to the lamp too) to get a decent display in a dimly lit room...

Approximate cost (given a good day on ebay): $200

interresting...

That's one thing that is cool about projectors, they don't devaluate very rapidly (check on ebay for anything 1-2 yrs old) compared to high-end TV. Plus it's not a pain in the ass to move around, plus you can have the size of screen that you want when you have 800+ lumens and good screen. (well obviously the more lumens the better if you're to do 15' diagonal :) )

When I see people buying HDTV TVs at C$5000+ I don't understand why they aren't looking a medium range projector with HDTV support. Okay you don't buy anything under XGA resolution because with all the resampling it'll screw up the quality big time, but still, at 5K you have a nice tv, but at 5K you have a BIG refurb projector that can do both progressive playback of your dvd, give you an image that has easily 4 time the area covered, and best of all, you can play quake at wall size!.

In my case I've been trying to grab a cheap DLP XGA projector for a while, I don't want a 60 inch tv that will be a pain to move around, I want a 90 inch "tv" that I'll be able to plug my computer on it and also have fun watching movies like in the theatre :).

The replacement lamps are very expensive, but then again, when you look at the "kit" they sell you for 400$, it's basically a specific lamp with specific properties (metal halide, etc etc) at a specific voltage, plus a little crappy plastic holder... there's no optics (you read "lamp module" you'd think it has some collimating lenses or something) and you can buy these same lamps from a third party at 1/5th of the price, and you just have to mount it back on the plastic thing that was attaching the old lamp. If you have to break it, so what, nothing a high-temperature epoxy can't fix.

Anyways, nice to see articles like that, but LCD sucks, DLP is the way to go for video projectors, too bad parts are still expensive, anyone here knows a 3rd party supplier that won't only sell developper kits at 3K$?

Here's an idea:

How about setting up this configuration, not with an LCD screen, but an old CRT monitor? Would the output be too dim? Could you crank the brightness, or would you then loose contrast?

i have dozens of old CRT's around for hacking.
could i just put a fresnel lense on one and aim it at a lense, then at a wall?

quality of the output

These projects and the directions look great, but there is something missing... None of these people have posted pictures of or described the quality of the output. As in, if you built one of these projectors, would you regret having laid out the $400, or would you be psyched and loving the high quality video image on your wall? I mean, I would be willing to make the investment for my own apartment, and would even bring one of these into my classroom (I am a teacher) to use with my classroom computer. But will the result be worth it?

Derek

Descaler? Huh?

I was going to ask why the article has all that equipment, but I guess it might be required if you're doing hi-res computer stuff on the screen (but then what's the point of hi-res? Why not just scale it down?). But if you just want to watch TV, all you would need is the overhead, panel (provided it has s-vid or RCA in) and a VCR or DVD player. Most of them nowadays have s-vid or RCA out (and s-vid to RCA is just a dumb converter away).

Television Ideas

This is giving me some rather good ideas..

I've been wanting to get an LCD projector for my living room, after playing with one from a club a year or so ago (the unit was already 3 years old). In average lighting in a friends house, we projected a TV image that was beautiful, from about 10 feet away, which made an image approx 5 feet tall.

I don't want to spend the $3k+ to buy one from the store, but I'm more than willing to spend less than $100 on a small handheld LCD TV and junk store movie/slide projector.

I'll post to Slashdot if it works. "Hacker Makes LCD TV/VGA projector for $100", with results. :) Now if someone would only approve that.. :)

Does it have to be so complex?

I have a better recipe for a homebrewed LCD projector:

1. Buy a typical overhead slide projector (the one your college has hundreds of)
2. Get a flat panel LCD @ 14-15"
3. remove the backlight from your flat panel
4. slap the panel stripped of the backlight on top of your overhead projector
5. Heh. There is no step 5!

Am I missing something or is this a better approach to the problem?

Rolls Eyes

Okay, a little better than the Big Screen with a CRT and Frenzel, but if you want good TV this is not it. If you want a good cheap LCD just go on ebay and buy a used 800x600.

Neat DIY, but really, it pushes forward all the things that are wrong with consumer AV. Low contrast rations, no idea about proper screen materials, poor color, bad scaling...you could go on and on about it.

Scam warning on building the LCD monitor described

Please note that the monitor suggested for the experiment (at this link [mp3playerstore.com]), claims to have a resolution of "960(H) X RGB x 240 (V)=230400" which can be a bit misleading if you're not too tech-savy on these numbers.

Note that the horizontal resolution is NOT 960 pixels, but rather 320, since they're counting each RGB pixel as THREE pixels (very sneaky indeed).

So just be warned in case you thought this was the deal of the century.

All I can say is...

WOOOOOHOOOO! Finaly! Now a cheap bastard like me can afford me some BIG SCREEN pr0n! Pass the quart of immitation butter flavoring please... /=^)

Dr MPF

Why Bother Projecting the LCD

If you can get decent quality 1-2" LCD screens, why not just rig them up on a pair of glasses, run the hardware off either a cable or a short range video transmitter and watch a seemingly immense screen with no noise, no bulbs...granted this is only good for one person... Shrug

Encounter w/ Law Enforcement

COP: Tell me son, why exactly were you purchasing a metal halide lamp?
GEEK: Well sir, I am a hobbyist, see
COP: interrupts A hobbyist, huh?
GEEK: yes, I am making a homegrown
COP: interrupts homegrown, huh? Son, you have the right to remain silent...
GEEK: LCD PROJECTOR! SIR!!! A HOMEGROWN LCD PROJECTOR!!! YOU KNOW, one of those things that projects computer images on the wall.
COP: Images on the walls. Hmmm...you must be pretty good at your "hobby"

Been thinking of this for a while...

Anyone know why I couldn't rip apart a handheld LCD TV, tear off the backlighting and use that?

No.

Sure, you can use a fairly normal lamp and a fairly normal LCD panel to produce large images on a wall. Heck, you can do it even cheaper with a bunch of colored markers, some saran wrap, and a light bulb.

If you absolutely do not care about video quality, it's easy to get/build a projector on the cheap.

However, today's typical $3500 projector includes:

- A truly full-spectrum lamp. Retail price: $425. Wholesale price: $300. Manufacturing price: $250.

- Built-in line doubler. Most LCDs have 768 vertical pixels; some have 600, some have 1024. DVD's have 525 vertical lines. VHS has something like 240 lines. How do you get from 525 or 240 to 768 or 1024? Anyone who knows anything about computer grahpics will realize that the answer is not "double every 1/X line". Line doublers interpolate lines on the fly.

- Progressive scan support. Again, not a huge big deal, but the way I read the article, not supported.

- Component video in support. Like progressive scan, increasingly critical for decent video.

- Distortion correction, especially trapezoid. It's very rare to be able to project from the geometric center of the screen. Most of us have to live with projecting from the ceiling or floor, and use optical or digital means to correct the image for that.

Sure, you can build a "projector" for $400. Heck, you can probably build one for $100 (see earlier lightbulb, saran wrap, and markers note). But if it were really that easy to produce a home theater quality projector for $1000, don't you think any of the mass producers would have done it? For less than the cost of a one-off? (Anyone who responds that all 8 major projector manufacturers are colluding in price fixing should be laughed at).

Cheers
-b

You need three panels

LCD projectors have one panel for each primary colour. They get mixed together so that white pixels look white. If you use only a single LCD panel, white pixels might look like separate red, green and blue stripes.

What a waste

OK, so these guys really expect me to believe that these cheesy $350+ hack jobs are going to have a better picture than a DLP projector, or a Barco? Please, don't waste my time. I can go on to E-bay and buy a Sony 1272 projector for about 700 bucks, which has RGB inputs and can handle at least the refresh rate of a 1024x768 SVGA resolution output if not more (I never tested a higher resolution on one). I used these things faithfully for 6 years on Corporate presentations when the power of a Barco or a DLP wasnt necessary. This ridiculous hack job reminds me of those $10 lenses you buy for your TV that is supposed to turn them into a projection set. Oh well, wasnt it PT Barnum who said "A sucker is born every minute" ?

Improvements I'd suggest

Use a polarising mirror and a wave plate, so that polarised light is passing through the LCD.

The reason for this is that with unpolarised light *half* of that light is just being absorbed by the LCD, and lost. This of course gets turned to heat and reduces the lifetime of your display.

Just buy a used projector

I bought a used projector on ebay - no hack value but plenty of instant gratification.
Here's another one...
Like New Epson Projector, Remote, Low Reserve [ebay.com]

Many things missing...

I'll try to list them.

You need a metal halide light bulb and ballast. Metal halide light bulbs are many many times more efficient at turning electricity into light, and thus produce far less heat. They also provide a 'whiter' light than a standard bulb. These are about $200 from hydroponics shops, and range in power from about 200-1000watts.

You need a 'cold filter' to block out the UV rays the light produces. Without this, the ultraviolet rays will actually start killing pixels. This happened to my projector. These little peices of glass alone cost around $200. But without one, you will cook an LCD very quickly, especially with higher powered lights.

By the time you get a decent lense, so you can actually get a decently sized and focussed image, you are starting to get into the sort of money that a decent 2nd hand projector goes for, without all the pitfalls.

But LCD is so passe

Digital Micromirrors. Thats what I'm talkin' about!

This is where the high end projectors are going to. The black levels from LCD projectors are horrid. With micromirrors, you can get true black. Truer black than even with film!

So I wonder if its possible to homebrew yourself one of these? I guess it comes down to being able to buy the micromirrors and associated electronics out on the market. Anyone have any knowledge in this area?

Cheap projectors...

A lot of people have commented on how these thing actually look, whether they actually work, and why anyone would want to do this when they could buy one used or new...

1. What do they look like? Depends mainly on the LCD and lens system, not to mention the "case" of the projector. If built right, with good components and a "light tight" case, it can look good. Not great, not HDTV ready, but good enough to watch TV or a video with.

2. Do they work? YES! Built right, they work as they should. LCD projection isn't anything really fancy - it is basically a slide projector with the LCD display substituted for the slide, and the backlight being a very bright lamp. You have to cool the LCD in some way (or polarise the light properly) to keep the LCD from "shutting down".

3. Why do this? I would say it is mainly a hobby, but I would also say it is because most of us can't afford a decent new or used projector. New projectors are hella expensive, and used ones maintain their value, and are thus not that cheap either. The only ones cheap enough are the large CRT projectors, which tend to be real heavy, need to be aligned after moving them, and need special support structures to hang the heavy weight from the ceiling (if that is how you want to mount yours).

I can't say I have ever built one of these projectors, but I can say how they probably look. I currently own a Fujix P401 portable LCD video projector. The thing is about the size of a couple of VHS tapes stacked upon one another, and it uses a small one inch LCD with a halogen lamp (it is a 6 volt halogen reflector lamp that is VERY difficult to find). It takes composite input, and has a system to either project on a small internal screen, or out to an external screen. Built in stereo speakers and the ability to run off of an 8mm video camera battery completes the system.

The quality is OK. At larger image sizes the pixels start to become apparent, but all in all it really isn't that bad of a projector. If I keep the image to around 40-50" diagonal, it is highly watchable (you need to be in a darkened room), great for videos. I have used a VGA->TV convertor successfully with it, and viewed VCDs under KDE.

I would expect a home-brew solution to be as good or better. I would imagine the larger LCDs to be higher resolution, and should give a sharper image at the larger sizes, with less "pixelization" (which really isn't a big deal on my P401).

I honestly don't understand why LCD projector manufacturers don't (or won't) make cheaper, lower-res units. I would think a 640x480 unit would only cost $500-700 - a lot of people would eagerly snatch it up. It could be made compact and lightweight. Make it easy to attach to a computer video card or composite/SVHS inputs. I think it could sell. I have a similar gripe regarding laptops (ie, why not a 640x480 cheap laptop), but now is not the place.

Re:/.'ed Already?

Two Words... "Google Cache". Of course, they specifically requested permission from the site before the blatantly copied the material from this site to thier caching servers, didn't they ?

Re:shut the fuck up

As if these guys are going to mount legal action against slashdot ... posting it here SAVES them money, its not like they've got a site full of banners. Keep up the good work, Taco

I never claimed the above post was illegal. Reread my reply. Troll.

Re:Whats to stop me...

Yep heat is the problem. Most of the pannels have special back glass to protect from heat and have colling fans.