Tinker:
ps1 panel on ebay sounds good. It does seem to indicate that you don't need to have it plugged into a ps1 to get joy out of it.
heat problems; the panel actually seems quite resistent, but I wouldn't push your luck. I am using a 250W halogen, and the heat from that is incredible. I use the hand test, if you can hold your hand there indefinitely without discomfort, should be right. My setup has an IR filter from a slide projector which cuts an enormous amount of heat. Without it you have to rip your hand away after 1 second or so, with it, your hand gets warm, but not a problem. I have decided my globe either doesn't put out enough light, or I am not using the light efficiently enough, so I have been looking around at alternatives as well. I figure pretty much all the alternatives will be larger format, so we would need a bigger IR filter. The best value seems to be stage light filters found by someone in another thread (forget who, have a search). I think they were US$20 for 12" square, and worked really well. I was gonna try and find a local (Aus) supplier for that stuff sooner or later. My next experiment though will be with a car headlight reflector and the 250W EHJ bulb with fresnel lenses to converge the light. This setup will definitely need the 12" square filter!
ps1 panel on ebay sounds good. It does seem to indicate that you don't need to have it plugged into a ps1 to get joy out of it.
heat problems; the panel actually seems quite resistent, but I wouldn't push your luck. I am using a 250W halogen, and the heat from that is incredible. I use the hand test, if you can hold your hand there indefinitely without discomfort, should be right. My setup has an IR filter from a slide projector which cuts an enormous amount of heat. Without it you have to rip your hand away after 1 second or so, with it, your hand gets warm, but not a problem. I have decided my globe either doesn't put out enough light, or I am not using the light efficiently enough, so I have been looking around at alternatives as well. I figure pretty much all the alternatives will be larger format, so we would need a bigger IR filter. The best value seems to be stage light filters found by someone in another thread (forget who, have a search). I think they were US$20 for 12" square, and worked really well. I was gonna try and find a local (Aus) supplier for that stuff sooner or later. My next experiment though will be with a car headlight reflector and the 250W EHJ bulb with fresnel lenses to converge the light. This setup will definitely need the 12" square filter!
Cant wait till mine gets here. It got shipped today!😀 I totally never thought about the psone lcd looking that good. Thanks for showing me that, for what it is and the cost I'm impressed. This is my first DIY projector (besides the reg. tv & fresnel deal) and the cheaper the better till I get a feel of what I'm doing and how I wanna do it. Still a total noob and cant wait to get my feet wet and chip info for the cause.
How bad were the ribbons to move out of your way? Super frail or just a little bendable? Thats the only part that has me nervous. Those ribbons. Would there be some way to maybe reinforce them before even moving them around at all. I work on pc's so I'm not a total clutz here but dont know how fragile these are any tips on that would be greatly apreciated.
Bulb size: "250W halogen"
Hmmm, thats probably a good place for me to start then. Halogen's should make more heat than MH. But then the cost of MH is alot higher. Like I said, Im going for 4' nothing giant but pretty big. I'll prob. try useing a halogen at first aswell. On the subject of filters. I have this pc mon filter. 15" Its tinted and anti-glair/anti-static shielded. If I hold my hand close to a commen house bulb 60watts where its pretty hot, then place this filter between my hand it cuts a real lot of heat out. Would this sufice for a filter or would it filter too much leaving me too little light? Anyone every try useing such a filter? I guess best bet would be to make my light source up while I'm waiting on the lcd and then feel it with my hand, the test you described. First without then with filter. Could I use a thermometer to check the temp. I have a black backed one. That may absorb as much heat as the lcd would during a dark scene. Kinda to test the worst temp case scenareo. Dont know-good idea? Bad idea? And what temp would I have to reference it to? I mean I cant find any data on any of these lcd's beyond you (thank you very much!!!) and a few other posts a search picked up on today. But alas the pic is good whatever res and contrast ratio it is. Hmm, I have much to think about I see.😉 😀
How bad were the ribbons to move out of your way? Super frail or just a little bendable? Thats the only part that has me nervous. Those ribbons. Would there be some way to maybe reinforce them before even moving them around at all. I work on pc's so I'm not a total clutz here but dont know how fragile these are any tips on that would be greatly apreciated.
Bulb size: "250W halogen"
Hmmm, thats probably a good place for me to start then. Halogen's should make more heat than MH. But then the cost of MH is alot higher. Like I said, Im going for 4' nothing giant but pretty big. I'll prob. try useing a halogen at first aswell. On the subject of filters. I have this pc mon filter. 15" Its tinted and anti-glair/anti-static shielded. If I hold my hand close to a commen house bulb 60watts where its pretty hot, then place this filter between my hand it cuts a real lot of heat out. Would this sufice for a filter or would it filter too much leaving me too little light? Anyone every try useing such a filter? I guess best bet would be to make my light source up while I'm waiting on the lcd and then feel it with my hand, the test you described. First without then with filter. Could I use a thermometer to check the temp. I have a black backed one. That may absorb as much heat as the lcd would during a dark scene. Kinda to test the worst temp case scenareo. Dont know-good idea? Bad idea? And what temp would I have to reference it to? I mean I cant find any data on any of these lcd's beyond you (thank you very much!!!) and a few other posts a search picked up on today. But alas the pic is good whatever res and contrast ratio it is. Hmm, I have much to think about I see.😉 😀
On a similar thought, before I forget. My dvd has R/G/B output. So if I had 3 identical psone lcd's (same make etc.) and used the rca in on each lcd (leaving driver boards intact etc.) One for Green, Blue-so on. Could you make a 3 panel projector. The ANSI lumens would be great and the bulb wouldnt have to be biger than like 150-200watts! 3 lcd's for like $150. I've seen how the sony projectors do it. With those mirrors which I've seen (dont know how much$) that pass all light but the color needed like red blue green to right panel and a prism to combine them then shot through a delta lens or whatever and bang a awsome semi cheap projector. That is unless prisms are really $. I dont know never checked on them?😕 Am I totally over my head and hopeless or could this actually work like that?😕
Wow Tinker that is really really complex. Getting all panels aligned would be a big pain! Plus those screens are all color one of the advantages of 3 lcd panel projectors is that you have each color of light going to the panel. So the sony ones still have three color filters to go through. Though you could probably get some cheap monochrome panels. Someone also posed instead of all the mirrors do like the crt projectors do. But of course this would require alignment.
Someone here had one without the cover on and that was when I was thinking of it. Heres a realy quick crappy drawing of it. (oops, file size too big it says)I'm prob. way off. Like CRT, you mean have 3 or even two full color lcd's images merged and projected then. A prisem will do that just the same wont it-I mean just like in the 3 panel deals right?
I see what you mean about the panel still fltering out the light. So you'd need monochrome ones to gain the ANSI-lumens advantage. Makes sense. Alls you would gain then would be contrast right? So a similar to crt type deal would make sense aswell. It would be brighter as more light would get through seeing how it would be x3 the panels. Even a single light source would still yield nearly 3x the effect as it (LCD panel) only uses about 10% of light source. So it would be more like 30% effective use of the light source. That is if your talking about converging the image, then projecting it. Hmmm, it would be easier too.😀
I see what you mean about the panel still fltering out the light. So you'd need monochrome ones to gain the ANSI-lumens advantage. Makes sense. Alls you would gain then would be contrast right? So a similar to crt type deal would make sense aswell. It would be brighter as more light would get through seeing how it would be x3 the panels. Even a single light source would still yield nearly 3x the effect as it (LCD panel) only uses about 10% of light source. So it would be more like 30% effective use of the light source. That is if your talking about converging the image, then projecting it. Hmmm, it would be easier too.😀
CRT like-like this? LOL bad drawing I know but you get what I mean. Am I thinking right? This way instead of 1 300watt bulb with alot of heat on one panel. You could have 3 100watt bulbs less heat per panel and more light useage cause of the 10% per panel thing it would be using 300watts 30% on 3 panels (10% each) instead of 10% of 300watts on one panel! It would be ruffly 3x brighter at the same watts and cooler per panel so I can see how it would work. But will a prism pull that together? Or will it have to be a mirror trick? Watcha think?😕
Attachments
No I was thinking along the lines of how a normal crt projector works with three different tubes that you see can on the outside. R G B . Then align the panels so they converge together with no prisms at all.
Tinker
Really tricky stuff aligning 3 LCD panels.
On a CRT projector there are mucho electronics that can size each tubes output so the image of all 3 lays on top of each other plus there are knobs for paralax adjustment, skew, barrel distortion, up, down, left, right, intensity etc all of which helps get 3 CRT images to register and look good. . You dont have all that flexibility or easy adjustment with 3 LCD's so guess it would be a lot harder to do.
The big guys do use a prism kind of thing to combine the 3 LCD images before sending it off to a projection lens. It is descibed a few pages back in this thread if you are interested.
Really tricky stuff aligning 3 LCD panels.
On a CRT projector there are mucho electronics that can size each tubes output so the image of all 3 lays on top of each other plus there are knobs for paralax adjustment, skew, barrel distortion, up, down, left, right, intensity etc all of which helps get 3 CRT images to register and look good. . You dont have all that flexibility or easy adjustment with 3 LCD's so guess it would be a lot harder to do.
The big guys do use a prism kind of thing to combine the 3 LCD images before sending it off to a projection lens. It is descibed a few pages back in this thread if you are interested.
Mario007 said:
Ohh I see! Yes, I know what you mean now-DUH, what was I thinking. Wouldnt that be really hard to align though aswell? Or is it alot more feasible that way? Heck you wouldnt even need three just two would still help alot.
One like this (normal crt). I know my Paintshop skills are, well I have non that about explains it.😉
Attachments
So how do you make the two converge at the screen without having them do the keystone efect or making the edge lightly out of focus. Is it more than just the mirror like digital or what? I have never gotten to see the inside of a real crt proection unit. To be honest I thought they just aligned the barrels (focusing tubes) to make them converge it and not a mirror. I guess I was wrong, do you have any links to where I can see how they do that? Thanks.🙂
Attachments
CRT projectors have a lot of electronic controls for pic size, position and shape which allows relatively easy convergence of the 3 images into one on the screen.
LCD panels don't have those controls to the same extent so its much harder to do. Nobody does it that way. They make 3 images with 3 panels and combine the 3 images in a single picture before it leaves the projector box.
You could try converging 2 or 3 individual pictures on screen but keystoning would ruin the whole picture.
LCD panels don't have those controls to the same extent so its much harder to do. Nobody does it that way. They make 3 images with 3 panels and combine the 3 images in a single picture before it leaves the projector box.
You could try converging 2 or 3 individual pictures on screen but keystoning would ruin the whole picture.
"You could try converging 2 or 3 individual pictures on screen but keystoning would ruin the whole picture."
Thats what I figured. that crt's used some kind of digital keystone correction, without you are lost.
"LCD panels don't have those controls to the same extent so its much harder to do. Nobody does it that way. They make 3 images with 3 panels and combine the 3 images in a single picture before it leaves the projector box. "
Yes, I know. They use a G R B lcd then they converge with a prism. The prism outputs into the focus tube. But you couldnt do this with say 2 color panels though right you need 3 and monochrome, I mean use a prism. And if you could it would be expensive finding good res./contrast panels that are that small. A prism that would do a 5" image would be very expensive I imagine. That means like a 2" lcd or whatnot. So that only really leaves the monochrome lcd's. That means needing a driver board! Now if you can get a 5" prism and you can converge two or three full color image with a prism -then horay, but I dont think it works that way. Actually I guess you could use a negative lense to make the image smaller to pass it into the prism at need size. But will a prism converge 3 all color panels or does it only work with monochrome?
😕
Thats what I figured. that crt's used some kind of digital keystone correction, without you are lost.
"LCD panels don't have those controls to the same extent so its much harder to do. Nobody does it that way. They make 3 images with 3 panels and combine the 3 images in a single picture before it leaves the projector box. "
Yes, I know. They use a G R B lcd then they converge with a prism. The prism outputs into the focus tube. But you couldnt do this with say 2 color panels though right you need 3 and monochrome, I mean use a prism. And if you could it would be expensive finding good res./contrast panels that are that small. A prism that would do a 5" image would be very expensive I imagine. That means like a 2" lcd or whatnot. So that only really leaves the monochrome lcd's. That means needing a driver board! Now if you can get a 5" prism and you can converge two or three full color image with a prism -then horay, but I dont think it works that way. Actually I guess you could use a negative lense to make the image smaller to pass it into the prism at need size. But will a prism converge 3 all color panels or does it only work with monochrome?
😕
Tinker,
They use 3 monochrome panels. Polysilicon ones that pass more light than the colour ones we use for projection. Impossible to locate I understand.
In this thread here the guys have tried very hard to find cheap small full colour panels to use with smaller optics. There is no loss of quality because the pixels are still sized so when magnified you get the same resoluton as a larger panel. That is if they both start with the same res. But there are a couple of problems
With small panels the percentage blocked by the colour filter transistors becomes greater than with a larger panel
Getting a good res small full colour panel is not easy
There is a higher concentration of light at the smaller panels so more steps need taken to remove heat.
Contrast is still an unsoved problem. Small panels are no better than big panels in this regard.
You have to look back in the tread and see for any success stories but I do know its very hard to find small colour panels with good resolution. Maybe you can find a good small panel.
They use 3 monochrome panels. Polysilicon ones that pass more light than the colour ones we use for projection. Impossible to locate I understand.
In this thread here the guys have tried very hard to find cheap small full colour panels to use with smaller optics. There is no loss of quality because the pixels are still sized so when magnified you get the same resoluton as a larger panel. That is if they both start with the same res. But there are a couple of problems
With small panels the percentage blocked by the colour filter transistors becomes greater than with a larger panel
Getting a good res small full colour panel is not easy
There is a higher concentration of light at the smaller panels so more steps need taken to remove heat.
Contrast is still an unsoved problem. Small panels are no better than big panels in this regard.
You have to look back in the tread and see for any success stories but I do know its very hard to find small colour panels with good resolution. Maybe you can find a good small panel.
Hi Tinker, the flat cables weren't too bad to move out of the way etc. Really I have kept the same orientation of the cable as it was when it was in the moulded madcatz housing. The actual high density ribbon between the driver and the lcd was coated in some sort of flexible black stuff. I was able to fold the driver back so the lcd/driver were flat again without a worry, but I wouldn't want to do it too many times. If you damaged that connection I don't think there's a hope of repairing it. The thing to remember with any unpluggable flat ribbon cables that may be present that they are not rated for many connect/disconnect cycles (maybe not even 10 for some). This is bad news for us experimenters who like to change things around all the time. The best thing to do is to mount the lcd and driver board and any other pcbs to a supporting structure very early, and try to avoid disassembling that from then on. It is inevitable as your design progresses, but at least that should keep unplugging it to a minimum, and also avoid bending the high density connections between the driver and lcd itself more than necessary.Tinker said:
On the filter front, I don't think those pc screen filters would be much chop, they are not designed to block IR as such, and probably the IR filtering effect you are getting is due to simple attenuation of IR as well as visible.
The black backed thermometer sounds like a great idea. I remember once adjusting my optics to try out an idea and not realising that I had inadvertently converged the light to quite a small spot on the lcd. The picture very quickly developed a dark spot in the middle where the lcd got too hot, and I dived for the power switch. Luckily I didn't permanently damage the panel, but it is something to watch out for.
Know of any sites where I can get a IR filter? WIll that stuff you use on cars to tint windows work? Thinking put that on a panel of glass before the lcd, dunno?😕 
Tinker
Any old glass will block heat. That is how glasshouses work. Lets light in, stops heat (IR) getting out. Two sheets with fan blowing air between will block more. Low E glass is supposed to be very good but someone said it is not very transparent. Have a search for low e see what you think. Best to place glass not near bulb where heat concentration is high but further away after light/heat spreads out.
Any old glass will block heat. That is how glasshouses work. Lets light in, stops heat (IR) getting out. Two sheets with fan blowing air between will block more. Low E glass is supposed to be very good but someone said it is not very transparent. Have a search for low e see what you think. Best to place glass not near bulb where heat concentration is high but further away after light/heat spreads out.
Thanks remp! So if I used two panels of glass with a fan inbetween to keep freh air moving betwen them that would drop the temp alot without any light loss-that would make sense. So the hole prob. with IR getting through is heat nothing else right? Hmm sounds like the best place for the panels of glass would be about 2" befrore the lcd after the light has traveled a little. Thank you.😀
Tinker,
Try and run your panel below 40 degrees centigrade. They will go higher until at about 60-70 C the panel will break up and not produce a picture Maybe get a blackness at the hotspot. It is unlikely to be permanently damaged but not good for prolonged heat exposure. You see the same thing with some watches in full sunshine on very hot day go black.
Infra Red ( IR ) is the heat component of light. Block out the IR and if you put your hand after the IR blocker its quite cool. If you can leave your hand there its ok.
Suggest set up glass block with out panel. Test for some time. Glass will be hot one side and cooler other side. Makes some stress in glass. Needs free mounting so can expand easy. Not tight fit in glass holder will be ok.
Hope this helps
Try and run your panel below 40 degrees centigrade. They will go higher until at about 60-70 C the panel will break up and not produce a picture Maybe get a blackness at the hotspot. It is unlikely to be permanently damaged but not good for prolonged heat exposure. You see the same thing with some watches in full sunshine on very hot day go black.
Infra Red ( IR ) is the heat component of light. Block out the IR and if you put your hand after the IR blocker its quite cool. If you can leave your hand there its ok.
Suggest set up glass block with out panel. Test for some time. Glass will be hot one side and cooler other side. Makes some stress in glass. Needs free mounting so can expand easy. Not tight fit in glass holder will be ok.
Hope this helps
It does and thank you very much! this is kinda like double and triple pane windows now that I think of it. That is minus the stuff the seal inbetween the panels. But by using a fan, you dont need that. Thats great. I will run it without the lcd panel for a while to find the temp with a thermometer. Thanks for the temps also, I had no idea at what temp the panel would react badly. Now I have a refrence to go with. 60-70 C that easy to remember, thats the max temp stable for a AMD XP. I'm a big pc geek I guess.🙄 Oh well I could be worse I guess huh.😀 
And having the panels not tightly fit makes sense aswell due to expansion and contraction, I didnt think about that-thats a great tip! I did notice that those IR filters were pretty dark. That'll loose alot more lumens than two panels of clear glass and a fan! I'm gonna do that!🙂
And having the panels not tightly fit makes sense aswell due to expansion and contraction, I didnt think about that-thats a great tip! I did notice that those IR filters were pretty dark. That'll loose alot more lumens than two panels of clear glass and a fan! I'm gonna do that!🙂What power lense should I need for a 4' image from a 5.6" diagnal screen. After messing around with my lense I dont think it is powerfull enuff. Besides its a fresnel and I dont think they are any good for this (use as objective lens). Right? I'm thinking of a 10x-12x lense with a 5"-10" focal length. Sound about right? 48"/5"=9.6". So a 10x would be (5.6" diag.x10) 56" diagnal and a 12x 67.2" diagnal image. Is this what you guys are doing. Thanks for all the help so far guys. After I get my first one working I will have a better understanding of all this. Thanks for any input you have on this problem.😕
Also wouldnt I need two lenses as to keep the color correct and not blurry at edges?
Also wouldnt I need two lenses as to keep the color correct and not blurry at edges?
- Status
- Not open for further replies.