Hi!
I have an old Sony VPL-SC50 projector. I've had it 1,5 years and I am pretty sure the light source will die any day now. I stumbled on the first DIY projector thread about a year a go and was very keen on trying super bright white leds as a new light source for my projector when the time comes.
Now the time'll probably come soon and I have been studying the subject more. I've browsed the whole thread I and also II for word LED and read all about it and the super bright LED thread, and I've come to conclusion that the main problems with brightness with any light source seems to be the problem to guide the light efficently enough by the means available to DIY builder.
I had a bit "provocative" topic for this thread, I am not actually absolutely sure if I am gonna try the LED -light source, at least sure YET. That is why I wrote on this forum, to get your opinions before actually buying the materials and so on.
Some stuff about the projector that might interest some:
- It has separate about 1" or so LCDs for red, green and blue
- 800x600 native resolution
I took the lamp out of the projector and noted that it has a reflector very much like some old flash light (well, that's not a suprise). The lamp itself is rated 120w, and the projector is supposed to give 500 ANSI lumens with it, which seems to be ok, picture is viewable even on bright days if I use normal shades. What was interesting about the optics right next to the lamp was that there was a "lens" or what ever probably for guiding the light in an even pattern for the LCD's (it looked like what I suppose that is on the other side of those dentist's lamps "lenses"). Based on this small detail I'd like to assume that the optics on this projector have been designed for the very efficient use of the light source. Another fact that supports this assumption is that the 120w lamp is not very powerful compared to 400-500w light sources used often by the DIY projector builders.
Ok, so how have I thought to go on with the project if the way would be to use the LEDs? The hole where the light comes out in the original lamp casing is about the size 6cm x 6cm, so I thought I'd use the original casing and just make a quite even pattern of leds to fill the 6cm x 6cm opening. That'd be something like 70 - 90 LEDs. The power source for the LED's would be old AT-PSU, and I'd be taking 12v from it for 3 leds adjustable with potentiometer so I'll be able to adjust the voltage lower than 4v if the leds seem to heat up. Also it might be useful (if this project would be reeeeaaaaally succesful) to be able to adjust the brightness lower at night time viewing to get better black.
The cost of the superbright white leds here in finland is about 1,5 euros each, so 70 of those would be something like 100 euros and probably there'll be some discount for such amount of leds being purchased. The price for the Sony's replacement lamp would be about 500 euros so... I am tempted like many others have been on this forum to go for the LEDs.
Mkay... whadda ya say, am I completely bonkers?
Regards
HB
I have an old Sony VPL-SC50 projector. I've had it 1,5 years and I am pretty sure the light source will die any day now. I stumbled on the first DIY projector thread about a year a go and was very keen on trying super bright white leds as a new light source for my projector when the time comes.
Now the time'll probably come soon and I have been studying the subject more. I've browsed the whole thread I and also II for word LED and read all about it and the super bright LED thread, and I've come to conclusion that the main problems with brightness with any light source seems to be the problem to guide the light efficently enough by the means available to DIY builder.
I had a bit "provocative" topic for this thread, I am not actually absolutely sure if I am gonna try the LED -light source, at least sure YET. That is why I wrote on this forum, to get your opinions before actually buying the materials and so on.
Some stuff about the projector that might interest some:
- It has separate about 1" or so LCDs for red, green and blue
- 800x600 native resolution
I took the lamp out of the projector and noted that it has a reflector very much like some old flash light (well, that's not a suprise). The lamp itself is rated 120w, and the projector is supposed to give 500 ANSI lumens with it, which seems to be ok, picture is viewable even on bright days if I use normal shades. What was interesting about the optics right next to the lamp was that there was a "lens" or what ever probably for guiding the light in an even pattern for the LCD's (it looked like what I suppose that is on the other side of those dentist's lamps "lenses"). Based on this small detail I'd like to assume that the optics on this projector have been designed for the very efficient use of the light source. Another fact that supports this assumption is that the 120w lamp is not very powerful compared to 400-500w light sources used often by the DIY projector builders.
Ok, so how have I thought to go on with the project if the way would be to use the LEDs? The hole where the light comes out in the original lamp casing is about the size 6cm x 6cm, so I thought I'd use the original casing and just make a quite even pattern of leds to fill the 6cm x 6cm opening. That'd be something like 70 - 90 LEDs. The power source for the LED's would be old AT-PSU, and I'd be taking 12v from it for 3 leds adjustable with potentiometer so I'll be able to adjust the voltage lower than 4v if the leds seem to heat up. Also it might be useful (if this project would be reeeeaaaaally succesful) to be able to adjust the brightness lower at night time viewing to get better black.
The cost of the superbright white leds here in finland is about 1,5 euros each, so 70 of those would be something like 100 euros and probably there'll be some discount for such amount of leds being purchased. The price for the Sony's replacement lamp would be about 500 euros so... I am tempted like many others have been on this forum to go for the LEDs.
Mkay... whadda ya say, am I completely bonkers?
Regards
HB
Hello Henry,
If you look at the bottom of the video threads page and set the thingy for threads last 90 days you will find a very long thread all about using small LCD panels. One guy there said he found a place to buy replecement lamps like you need at very cheap price. He tried one and think he said it worked fine. About 15 British pounds from memory. Would that be 15 Ero. ?
Using the LED's yep you are bonkers. Just kidding. Too expensive, Too hard, Too frustrating. You can pulse normal LED's to get double or triple the light from them. Trouble with high intensity white LED's is they dont have much green in them. They are on a blue substrate with some material on top that gives white. I think thats correct. You need something thats got the red, blue and green in it like a proper light else it won't be separated out inside your projector. (presume its a 3 panel unit).
It would be worth trying out a few for experiments. Then see if there is any potential.
If you look at the bottom of the video threads page and set the thingy for threads last 90 days you will find a very long thread all about using small LCD panels. One guy there said he found a place to buy replecement lamps like you need at very cheap price. He tried one and think he said it worked fine. About 15 British pounds from memory. Would that be 15 Ero. ?
Using the LED's yep you are bonkers. Just kidding. Too expensive, Too hard, Too frustrating. You can pulse normal LED's to get double or triple the light from them. Trouble with high intensity white LED's is they dont have much green in them. They are on a blue substrate with some material on top that gives white. I think thats correct. You need something thats got the red, blue and green in it like a proper light else it won't be separated out inside your projector. (presume its a 3 panel unit).
It would be worth trying out a few for experiments. Then see if there is any potential.
Ok, I'll think I'll check what the store that sells LED's offers me and depending on the price I'll probably take something like 25-50 LED's just for close range testing. If the image is has good colours and is nice and bright in 2 meter distance of the projector when using 25 leds it should be about the same quality and especially brightness at 4 meters and about 100 leds, right? Isn't that how the fysics with light on this matter work or am I still raving mad bonkers? =)
Well, remp's answer was useful but I'd like to hear more if someone has something to say to this.
Oh, I almost forgot, where was those 15 pound lamps obtained and for what projector they were? Anyway, I'd really loved to get these led arrangements work... the noise of the fans is almost painful.
Hey how about if I stick just a few super bright green ones with the whites, It should mend the matter. The optics on my projector seem to be able to take quite mixed light and make it very homogenous stuff for the lcd's... I am not sure but I guess cause of that weird "lens" right next to the lamp.
Regards
HB
Well, remp's answer was useful but I'd like to hear more if someone has something to say to this.
Oh, I almost forgot, where was those 15 pound lamps obtained and for what projector they were? Anyway, I'd really loved to get these led arrangements work... the noise of the fans is almost painful.
Hey how about if I stick just a few super bright green ones with the whites, It should mend the matter. The optics on my projector seem to be able to take quite mixed light and make it very homogenous stuff for the lcd's... I am not sure but I guess cause of that weird "lens" right next to the lamp.
Regards
HB
Sorry, not bonkers, you just have not gone through the math.
Last poster is correct, white LEDS do not have much green, and in fact, the red component may not line up well with the color filters on your LEDS. It would be far better to use Red, Green, and Blue LEDS. Okay, you are looking at 90 LEDS, those LEDS will be rated at say 100 to 200 milliwatt! Best case, you are looking at 18 watts! Guess what, those white LEDS have only 1/4 the luminous efficiency of that projector bulb. Hence, those 90 white LEDS, if they work at all, will only be as 1/20th - 1/30th the brightness of your 120watt bulb.
That is not to say that you could not use LEDS to make a projector, it just will not be cheap or easy. For one, you would want to direct only the red LEDS at the red panel, blue at the blue panel , etc. Doing this will give you at 3-5 times improvement over using a white source. Second, you will need to use an extremely high density LED array. Possibly an array of surface mount LEDS would work, but I would almost think you would need to go with die. Third, you would need to get rid of the large amounts of heat. 80% of the power going into your LED will become heat. You need to get rid of that or you are going to cook your LEDS. That 100,000 hour light source will suddenly become 10K hours and the color will shift. Think aluminum core boards, big heat sinks or liquid cooling, etc.
Would it be worth doing? Well, if I could pay an extra 3K for a projector and know that it was going to last 10 years without a bulb replacement runnning 8 hours a day, i.e. if it was as reliable as a TV, then I would pay the extra.
Alvaius
Last poster is correct, white LEDS do not have much green, and in fact, the red component may not line up well with the color filters on your LEDS. It would be far better to use Red, Green, and Blue LEDS. Okay, you are looking at 90 LEDS, those LEDS will be rated at say 100 to 200 milliwatt! Best case, you are looking at 18 watts! Guess what, those white LEDS have only 1/4 the luminous efficiency of that projector bulb. Hence, those 90 white LEDS, if they work at all, will only be as 1/20th - 1/30th the brightness of your 120watt bulb.
That is not to say that you could not use LEDS to make a projector, it just will not be cheap or easy. For one, you would want to direct only the red LEDS at the red panel, blue at the blue panel , etc. Doing this will give you at 3-5 times improvement over using a white source. Second, you will need to use an extremely high density LED array. Possibly an array of surface mount LEDS would work, but I would almost think you would need to go with die. Third, you would need to get rid of the large amounts of heat. 80% of the power going into your LED will become heat. You need to get rid of that or you are going to cook your LEDS. That 100,000 hour light source will suddenly become 10K hours and the color will shift. Think aluminum core boards, big heat sinks or liquid cooling, etc.
Would it be worth doing? Well, if I could pay an extra 3K for a projector and know that it was going to last 10 years without a bulb replacement runnning 8 hours a day, i.e. if it was as reliable as a TV, then I would pay the extra.
Alvaius
I got the camera back so I have few images about the project at my website http://tweaknmod.tk. Language is finnish but well, the images are of course universal so go and see what the inside and the lamp looks like in the projector that I am working on. If someone knows where to obtain the same kind (or close) of lamps that is in the images then please tell me because I just made few alterations to the cooling of the projector as you can see on the images and now it is very silent... I might postpone the LED-project of mine if I can find cheap replacement bulbs.
Also, if someone knows what the weird lens right after the lamp is and what it does (the reddish one) I'd be happy to know.
Regards HB
Also, if someone knows what the weird lens right after the lamp is and what it does (the reddish one) I'd be happy to know.
Regards HB
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