NICE! Yeah, the more resolution, the better! I thought about using 3 LCDs, but wasn't sure where to find the monochrome LCDs. That would be an excellent experiment. Only thing being that alignment becomes more of an issue, but probably worth it. It would be brighter and I beieve it can create even more colors. Check out my original post on page one. Look for the Sharp site. It shows the setup for 3 LCD projectors. You need to use dichrotic mirrors that only reflect the color for say red, green, or blue. But if you use LEDs as a light source, it won't need to be as complicated.
How bright was it? Don't even think about looking into it's path! It hurts even for a split second. It really is like a spot light. Perfect circle too. When I first ran it w/ the single lense, you could see there were patches of dark because of how I set up my LEDs on seperate tiny boards. Not w/ a condenser though. It was evenly dispersed. I'm also testing it w/ an open case, so there is light polution in the room.
I recommend ONE board w/ a tight grouping of LEDs.
I tried to be fancy and make a pattern like an octagon, but it's tough, unless you make your own board. I used perfboard and hard-wired them.
I would love to try something w DLPs! You would only need one. One of you guys linked to a site where they show how that's done. That would be the way to go. I also have white papers on how CRT projectors work. I'm basing my work on both LCD and CRT, like a hybrid.
Vince
How bright was it? Don't even think about looking into it's path! It hurts even for a split second. It really is like a spot light. Perfect circle too. When I first ran it w/ the single lense, you could see there were patches of dark because of how I set up my LEDs on seperate tiny boards. Not w/ a condenser though. It was evenly dispersed. I'm also testing it w/ an open case, so there is light polution in the room.
I recommend ONE board w/ a tight grouping of LEDs.
I tried to be fancy and make a pattern like an octagon, but it's tough, unless you make your own board. I used perfboard and hard-wired them.
I would love to try something w DLPs! You would only need one. One of you guys linked to a site where they show how that's done. That would be the way to go. I also have white papers on how CRT projectors work. I'm basing my work on both LCD and CRT, like a hybrid.
Vince
MonoChrome Displays
http://www.citizen-america.com/OEM/lcd/tb56.htm
Here's one that would be perfect.
http://www.citizen-america.com/OEM/lcd/tb56.htm
Here's one that would be perfect.
Try this place for help. Let us know if you figue this out. I'm going to try to figure out how to input R-G-B inputs for the screen I have with component or S-Video. If it's a known screen, some of these guys may be able to help.
http://www.eio.com/lcdintro.htm
http://www.eio.com/lcdintro.htm
Hi Robin,
I have an old laptop with worn out battery and 14"/800x600 TFT. The processor is too slow to play MPEG etc and DVD...
i also wonder if the TFT is fast enough.
Haven't had time yet to open it up and see if a bright back light can be added...
How do you plan to get analog video into the box? Maybe it would be easiest to get a outboard video card (pcmcia tv card?) but of course quality would suffer.
Timo
I have an old laptop with worn out battery and 14"/800x600 TFT. The processor is too slow to play MPEG etc and DVD...
i also wonder if the TFT is fast enough.
Haven't had time yet to open it up and see if a bright back light can be added...
How do you plan to get analog video into the box? Maybe it would be easiest to get a outboard video card (pcmcia tv card?) but of course quality would suffer.
Timo
For interfacing (laptop) lcd screen with PAL/NTSC video take a look at http://www.sageinc.com/products/boardsupport.html
And click on the Puma 2, it seems the perfect board for doing just that! (Although I don't know the price :-(
Robin
And click on the Puma 2, it seems the perfect board for doing just that! (Although I don't know the price :-(
Robin
Take a look at http://www.noah.org/acidwarp/warper.html
It's a (very) low budget video projection project. It uses a normal (computer) monitor and a fresnel lens. (about $25,-) I suppose the brightness of this system is very low but I imagine that a LCD panel with a beefed up backlight (50 white leds) would give a pretty good image. (In the original design the image is upside down but turn the LCD would fix that
Robin
It's a (very) low budget video projection project. It uses a normal (computer) monitor and a fresnel lens. (about $25,-) I suppose the brightness of this system is very low but I imagine that a LCD panel with a beefed up backlight (50 white leds) would give a pretty good image. (In the original design the image is upside down but turn the LCD would fix that
Robin
The Warper is coool. ...
What i have in mind is similar, but uses the lens of a OHP (overhead projector). The image has to be sharp, i have to be able to read text on the projected image so a fresnel lens is not an option.
I would first set this up "warper-style" without additional backlight. But first i need to find a lens.
OHP lenses should be available from the manufacturers as spare parts.
Timo
What i have in mind is similar, but uses the lens of a OHP (overhead projector). The image has to be sharp, i have to be able to read text on the projected image so a fresnel lens is not an option.
I would first set this up "warper-style" without additional backlight. But first i need to find a lens.
OHP lenses should be available from the manufacturers as spare parts.
Timo
Robin,
That's what I need. Just have to make sure it will interface w/ my LCD screen. Sounds like it will.
There is a site that might have what you need. They have prices too.
http://www.earthlcd.com/
That's what I need. Just have to make sure it will interface w/ my LCD screen. Sounds like it will.
There is a site that might have what you need. They have prices too.
http://www.earthlcd.com/
Found DLP Chips for sale!
Found DMD chips for DLP projectors, with several relivent parts. Here's the site.
http://www.lasersurplus.com/optics.htm
Found DMD chips for DLP projectors, with several relivent parts. Here's the site.
http://www.lasersurplus.com/optics.htm
hmm, it doesn't look like they come with a controller, and I didn't see any controllers for sale on that site. Do you know where to get a controller, or even what would we need? They don't give much info about that part, and I suspect it would be hard to find a controller. although maybe a pc could be used oooohh that could be fun to program a controller.
oooohh that could be fun to program a controller.
I don't know what kind of driver board DMD Chips use. That's a whole other ball of wax I don't want to roll up into right now. I put that out there for anyone else's interest.
I've been messing around w/ my projector over the past few nights, and I feel it's coming along nicely. There a few things I need to over come to get this project to work at its best.
For one, w/ 48 LED, it's not bright enough w/out a condenser lense. In a darkened room, with minimal ambient light, the image is less then optimal. I ordered a condenser from Surplus Optics- 6" diameter plano convex. I'm hoping this will help some. I don't think it will make it worse. If it doesn't help considerably, I'll pick up more LEDs.
From 5 feet out, the image was 6 feet wide, but because the LCD is 5.6" diagonally, while the projection lense is 2.5" at the opening, some of the image at the sides is cut off.
I think I need to find an optical quality lense to correct this problem. Pulling the LCD back from the projector lense doesn't help because there isn't enough focus to adjust for the focal length. I could find a smaller LCD screen. That would work for sure, but would be expensive as opposed to trying to correct the aboration with another lense. I'll try the lense first.
On the positive side:
If you are sitting about 8' to 10' from the screen, the pixels aren't too distracting.
The LEDs don't get warm at all. I let it run for 2 hours and there was no heat. Some ventilation would do the trick. There would be no need for a fan w/ 48 LEDs. I don't think 96 LEDs would be all that different.
I tried to take a picture, but I don't know if it will come out. If it does, I will put it on my web site, but don't expect a miracle.
Vince
I've been messing around w/ my projector over the past few nights, and I feel it's coming along nicely. There a few things I need to over come to get this project to work at its best.
For one, w/ 48 LED, it's not bright enough w/out a condenser lense. In a darkened room, with minimal ambient light, the image is less then optimal. I ordered a condenser from Surplus Optics- 6" diameter plano convex. I'm hoping this will help some. I don't think it will make it worse. If it doesn't help considerably, I'll pick up more LEDs.
From 5 feet out, the image was 6 feet wide, but because the LCD is 5.6" diagonally, while the projection lense is 2.5" at the opening, some of the image at the sides is cut off.
I think I need to find an optical quality lense to correct this problem. Pulling the LCD back from the projector lense doesn't help because there isn't enough focus to adjust for the focal length. I could find a smaller LCD screen. That would work for sure, but would be expensive as opposed to trying to correct the aboration with another lense. I'll try the lense first.
On the positive side:
If you are sitting about 8' to 10' from the screen, the pixels aren't too distracting.
The LEDs don't get warm at all. I let it run for 2 hours and there was no heat. Some ventilation would do the trick. There would be no need for a fan w/ 48 LEDs. I don't think 96 LEDs would be all that different.
I tried to take a picture, but I don't know if it will come out. If it does, I will put it on my web site, but don't expect a miracle.
Vince
How'd you like to have your very own jumbotron? PE sells Red, Green, and Blue superbright LED's. All you'd need is some fancy-dancy controller for all those LED's, it would be a nice direct-view...
http://www.partsexpress.com/pe/showprod.cfm?&DID=7&CATID=48&ObjectGroup_ID=554
http://www.partsexpress.com/pe/showprod.cfm?&DID=7&CATID=48&ObjectGroup_ID=554
Think About It
Hi All,
I have an idea on how to construct a relatively cheap projector:
Visit http://www.kopin.com site where you can have a look at the super small high-resolution screens. (Cheap too)
Now using the screen it is possible to construct/buy a VGA - to - screen converter and use any overhead projector (modified optics...) to project a computer image.
What do you think?
Hi All,
I have an idea on how to construct a relatively cheap projector:
Visit http://www.kopin.com site where you can have a look at the super small high-resolution screens. (Cheap too)
Now using the screen it is possible to construct/buy a VGA - to - screen converter and use any overhead projector (modified optics...) to project a computer image.
What do you think?
Hi Akula,
I think 640x480 is too low resolution. Another disadvantage that i see with this small display is that it will be difficult to put alot of light through it. Overhead projector optics would be better suited to a larger screen in my opinion.
Well, it's only my opinion anyway i am no specialist in optics.
Now that the larger TFT screens (15") get cheaper, i wonder if it is possible to beef up the backlight to projector specs (100 white leds). That would be wonderful... The good LG display is 600 $ at the moment, and because it could be used as normal computer monitor as well i think this is a possible choice.
Please can anyone inform me how the backlight is usually made in computer TFT monitors? Can the back panel / light be removed to have access to the LCD panel from both sides?
Thanks, keep going everybody
Timo
I think 640x480 is too low resolution. Another disadvantage that i see with this small display is that it will be difficult to put alot of light through it. Overhead projector optics would be better suited to a larger screen in my opinion.
Well, it's only my opinion anyway i am no specialist in optics.
Now that the larger TFT screens (15") get cheaper, i wonder if it is possible to beef up the backlight to projector specs (100 white leds). That would be wonderful... The good LG display is 600 $ at the moment, and because it could be used as normal computer monitor as well i think this is a possible choice.
Please can anyone inform me how the backlight is usually made in computer TFT monitors? Can the back panel / light be removed to have access to the LCD panel from both sides?
Thanks, keep going everybody
Timo
Akula, I think they're perfect! This is what I have been looking for since I started this thread.
640x480 is do-able. At http://www.earthlcd.com there are driver boards that will double the native resoultion, and will set the system up w/ s-video. The Puma 2 from Sage, Inc. will do the same. Both companies have driver boards that will work w/ PC inputs.
The smaller size is so much easier to work w/ since most of the optics I have found are 25mm's and up. Mirrors, Aspheric, Achromats, ect., are much easier to find in small sizes.
Timo,
the lighting in screens monitor is usually side lit w/ cold florescent lighting, or the same in a frame shape (rectangular bulb) around the LCD screen. I removed the one I had. Just try not to touch the LCD too much, to avoid prints.
...I may have to rethink this whole project now.
Thanks!
Vince
[Edited by vdi_nenna on 07-31-2001 at 09:33 AM]
640x480 is do-able. At http://www.earthlcd.com there are driver boards that will double the native resoultion, and will set the system up w/ s-video. The Puma 2 from Sage, Inc. will do the same. Both companies have driver boards that will work w/ PC inputs.
The smaller size is so much easier to work w/ since most of the optics I have found are 25mm's and up. Mirrors, Aspheric, Achromats, ect., are much easier to find in small sizes.
Timo,
the lighting in screens monitor is usually side lit w/ cold florescent lighting, or the same in a frame shape (rectangular bulb) around the LCD screen. I removed the one I had. Just try not to touch the LCD too much, to avoid prints.
...I may have to rethink this whole project now.
Thanks!
Vince
[Edited by vdi_nenna on 07-31-2001 at 09:33 AM]
I'll second that
yup, its perfect. the size might even allow you to use widely available slide projector lenses, since it is a similar size to slides. still, I wish it were a little cheaper especially the monochrome ones. I'm still looking at monochrome, because in their product description, the say that the color is achieved by rapidly displaying each RGB channel in succession. I'm not sure if this is how all active matrix lcd's work, but I suspect not. anyhow, this means that its probably more like the single chip dlp's with a color wheel in terms of the lack of contrast and brightness when comapred to three serparate units.. but of course you wouldn't have any convergence issues.
I have a question about price though - on the ordering page, I only saw info regarding the 320 models do you know where to get prices on the 640 or 1280 models as well?
Evan
yup, its perfect. the size might even allow you to use widely available slide projector lenses, since it is a similar size to slides. still, I wish it were a little cheaper
especially the monochrome ones. I'm still looking at monochrome, because in their product description, the say that the color is achieved by rapidly displaying each RGB channel in succession. I'm not sure if this is how all active matrix lcd's work, but I suspect not. anyhow, this means that its probably more like the single chip dlp's with a color wheel in terms of the lack of contrast and brightness when comapred to three serparate units.. but of course you wouldn't have any convergence issues. I have a question about price though - on the ordering page, I only saw info regarding the 320 models do you know where to get prices on the 640 or 1280 models as well?
Evan
I don't think I'll be using microdisplays any time soon.
This is a quote-
The 320 is available today in volume..If you would like a quote on this please contact Sylvia Zhang at our Westboro, MA. office here email address is szhang@kopin.com. However, the display is not configured for a
projector application and the 320 violates your requirement for resolution being "as high as possible". We have a 1280 display evaluation kit. The cost is $7500. The 1280 monochrme displays (they do not come in color) are
$3000. each. This will operate with the brightness you need but is monochrome. For R&D work it should be ok. Color can be done several ways later.
I got another quote and it was about the same price. It's just not do-able.
Vince
This is a quote-
The 320 is available today in volume..If you would like a quote on this please contact Sylvia Zhang at our Westboro, MA. office here email address is szhang@kopin.com. However, the display is not configured for a
projector application and the 320 violates your requirement for resolution being "as high as possible". We have a 1280 display evaluation kit. The cost is $7500. The 1280 monochrme displays (they do not come in color) are
$3000. each. This will operate with the brightness you need but is monochrome. For R&D work it should be ok. Color can be done several ways later.
I got another quote and it was about the same price. It's just not do-able.
Vince
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