I know that people have been interested in using LEDs to use for projector lighting for a little while, and I just saw a person sellnig 9000mcd LEDs for $1 each. I don't want to link to the site because I dont' think they have very much bandwidth, but if anyone thinks that it is a possible solution then I will provide a link.
The specs are: (that this person posted)
8000-9000mcd
viewing angle: 20*
reverse voltage: 5v
size: 5mm
Again, I don't know the relationship between candelas and lumens, but if there is an equation that one might be able to use give it a go. At $1 each LED, they're pretty cheap too.
If you want the address I CAN post it...but I just don't want to slow this guy's site down substantially if no one thinks it would be possible...you know?
The specs are: (that this person posted)
8000-9000mcd
viewing angle: 20*
reverse voltage: 5v
size: 5mm
Again, I don't know the relationship between candelas and lumens, but if there is an equation that one might be able to use give it a go. At $1 each LED, they're pretty cheap too.
If you want the address I CAN post it...but I just don't want to slow this guy's site down substantially if no one thinks it would be possible...you know?
k..if I'm not mistaken, that makes each LED about 104 lumens. The site says it can be misleading though, so it's hard to say.
9(2pi*(1 - cos (.5 * (20)))) = 103.555
yay? nay?
9(2pi*(1 - cos (.5 * (20)))) = 103.555
yay? nay?
allternative to HID?
I came across these today, I'm looking at allternatives to HID lighting for my PJ. I've considered the LED route but dont want the hassle of "clustering" a couple thousand REALLY expensive LED's.
Then I found these http://www.sunstreamer.com/index.htm if they can be run on a regular Flouro ballast then all that is special is the tube. Granted at 2feet long/tube it would mean a PJ box of probably 26 inchs or so square...but the distance to the LCD panel could concieveably be quite close (still with some fan venting and an insulating sheet of glass (low E?) I think).
The "end mounts" for a flourescent tube are available in many config's so they could be custom mounted allowing for VERY close together spacing of the tubes (thinking ohh maybe 12 or 14 tubes?).
Any thoughts?
if your not livin on the edge...you're takin up too much space!
zardoz
I came across these today, I'm looking at allternatives to HID lighting for my PJ. I've considered the LED route but dont want the hassle of "clustering" a couple thousand REALLY expensive LED's.
Then I found these http://www.sunstreamer.com/index.htm if they can be run on a regular Flouro ballast then all that is special is the tube. Granted at 2feet long/tube it would mean a PJ box of probably 26 inchs or so square...but the distance to the LCD panel could concieveably be quite close (still with some fan venting and an insulating sheet of glass (low E?) I think).
The "end mounts" for a flourescent tube are available in many config's so they could be custom mounted allowing for VERY close together spacing of the tubes (thinking ohh maybe 12 or 14 tubes?).
Any thoughts?
if your not livin on the edge...you're takin up too much space!
zardoz
Defmike:
I'm willing to give this a shot now I think, and if nothing else I think I'll buy 20 of these 9000 mcd LED's and see how well it works in a retrofit of a laptop LCD. Still got that link? Cheapest I've found 9k or 10k LED's is $1.68
Thanks!
--Clint
I'm willing to give this a shot now I think, and if nothing else I think I'll buy 20 of these 9000 mcd LED's and see how well it works in a retrofit of a laptop LCD. Still got that link? Cheapest I've found 9k or 10k LED's is $1.68
Thanks!
--Clint
ughhh
.. booo.. no one listens to me... booo.. o well. The one i was talking about in the laser post, was the luxeon, it claims to be the brightest led at 16$ each, we could use about 3 or 4 and most likely get good results. They even use one of these leds in a flashlight, so they cant be to dim. yeah but anyway, look for luxeons. LEDs are they way to go, way less power consumtion, way longer life, and little to no heat, which results in no fan noise.
.. booo.. no one listens to me... booo.. o well. The one i was talking about in the laser post, was the luxeon, it claims to be the brightest led at 16$ each, we could use about 3 or 4 and most likely get good results. They even use one of these leds in a flashlight, so they cant be to dim. yeah but anyway, look for luxeons. LEDs are they way to go, way less power consumtion, way longer life, and little to no heat, which results in no fan noise.
I can get 10cd (10,000mcd) white LEDS for $2 Australian, does this work out less money per light??
Ohh, wait, you get 10% discount for 10 or more.. 🙂 $1.80 each.. lol
Ohh, wait, you get 10% discount for 10 or more.. 🙂 $1.80 each.. lol
hmm
thats pretty cheap, not compairable, but cheap.. the 660,00 is about 13-16$ u.s. But i wouldnt want to order one and mess it up, knowing me that will happen. So im most likely gonna go with a few cheaper less powerfull ones, untill they drop in cost.
thats pretty cheap, not compairable, but cheap.. the 660,00 is about 13-16$ u.s. But i wouldnt want to order one and mess it up, knowing me that will happen. So im most likely gonna go with a few cheaper less powerfull ones, untill they drop in cost.
leds are hard to mess up. The only thing you can do wrong is pump to much voltage in them, and if you have a lab power supply, your all set.
sadly
sadly Iam the master at messing up leds, i went through a few packs when i was a raver, trying to make my blinky visor.... 🙄
sadly Iam the master at messing up leds, i went through a few packs when i was a raver, trying to make my blinky visor.... 🙄
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=26207&item=3104552672
1 Watt White LED Luxon Star s... 12 bucks each.
1 Watt White LED Luxon Star s... 12 bucks each.
Poohbear:
I fully understand the Star-O's, and how incredible they are. 🙂 I've posted about them extensively, including alot of calculations about them. I think they're wonderful.
I mainly just want to spend $25 or so in LED's to see if I can get a reasonably bright image with a simple LCD panel, and not have to mess with the heat sinks and other such things of the Star's.
Also, to line an entire LCD panel bottom edge with Star's would cost a fair bit of money (in order to get even distribution)... If a row of 10k mcd's is a whole lot brighter than the single CCFT that normally lights LCD panels (and you can project an okay image just using that CCFT), I think we can get a pretty good image if the row of LED's is 5x or 8x brighter than the normal backlight.
Thoughts?
--Clint
I fully understand the Star-O's, and how incredible they are. 🙂 I've posted about them extensively, including alot of calculations about them. I think they're wonderful.
I mainly just want to spend $25 or so in LED's to see if I can get a reasonably bright image with a simple LCD panel, and not have to mess with the heat sinks and other such things of the Star's.
Also, to line an entire LCD panel bottom edge with Star's would cost a fair bit of money (in order to get even distribution)... If a row of 10k mcd's is a whole lot brighter than the single CCFT that normally lights LCD panels (and you can project an okay image just using that CCFT), I think we can get a pretty good image if the row of LED's is 5x or 8x brighter than the normal backlight.
Thoughts?
--Clint
yes
good point clint, I read that the stars needed heat sinks and decided they werent the answer, because the point of leds would be partly because of there extremly low heat output. also with 5k mcd leds i dont think you would need a whole panel, maybe a panel with about 10 placed in the right spots and using the material i found under my psone lcd. The material is like a sheet that spreads the backlight evenly, so maybe im wrong but it should do the same with a few leds. eitherway, i cant wait to get my ohp (should be here tomorrow) so i can play with lighting options!
good point clint, I read that the stars needed heat sinks and decided they werent the answer, because the point of leds would be partly because of there extremly low heat output. also with 5k mcd leds i dont think you would need a whole panel, maybe a panel with about 10 placed in the right spots and using the material i found under my psone lcd. The material is like a sheet that spreads the backlight evenly, so maybe im wrong but it should do the same with a few leds. eitherway, i cant wait to get my ohp (should be here tomorrow) so i can play with lighting options!
I actually want to illuminate the LCD from the side, as in the attached picture.
This uses the existing optics (which spread it evenly), and just replaces the light source with a much more powerful one.
However, as I really have been unable to find information regarding the brightness of a CCFT, I don't know how much brighter a row of LED's would be.
Anyone know how bright a row of 10,000 mcd LED's would be in comparison to a standard CCFT? If it's not at least 3x brighter, I don't think you would get a decent projected image.
--Clint
This uses the existing optics (which spread it evenly), and just replaces the light source with a much more powerful one.
However, as I really have been unable to find information regarding the brightness of a CCFT, I don't know how much brighter a row of LED's would be.
Anyone know how bright a row of 10,000 mcd LED's would be in comparison to a standard CCFT? If it's not at least 3x brighter, I don't think you would get a decent projected image.
--Clint
Attachments
The Luxeons require a heat sink because of the amout of power they can generate. Using standard 5mm LEDS, will generate as much heat (actually more because they tend to be less efficient), it just won't be concentrated in as small an area.
If you want to backlight an LCD, the standard Star is not the way to go. Luxeon makes a side emitting LED, essentially a Star with a cone on top that makes the light go out sideways. This will make it much easier to design. However, the way to do it is not with white LEDS, but with Red, Green, and Blue Luxeons. The basic design of a side lit backlight makes the mixing of the LEDS colors easy. Luxeon has a demo backlight for I believe a 15" LCD that if passed through a panel would generate somewhere on the order of 1,000-1,500 NITS, maybe a bit more. I believe it uses somewhere on the order of 28-35 Luxeon LEDS in a combination of 5 watt Blue and Green Luxeon's and 1 watt RED Luxeons. Mitsubishi has just released commercial panels using Luxeons, but not as bright:
http://www.lumileds.com/newsandevents/releases/Dec_04_2002_Mitsu_PR.pdf
However, at this point in time, you could generate the same amount of backlight for about 1/2 the electrical power with CCFL tubes.
For the Luxeons, you can order any that they have from http://www.future-active.com/ . They are the official distributor for the product.
If you want to backlight an LCD, the standard Star is not the way to go. Luxeon makes a side emitting LED, essentially a Star with a cone on top that makes the light go out sideways. This will make it much easier to design. However, the way to do it is not with white LEDS, but with Red, Green, and Blue Luxeons. The basic design of a side lit backlight makes the mixing of the LEDS colors easy. Luxeon has a demo backlight for I believe a 15" LCD that if passed through a panel would generate somewhere on the order of 1,000-1,500 NITS, maybe a bit more. I believe it uses somewhere on the order of 28-35 Luxeon LEDS in a combination of 5 watt Blue and Green Luxeon's and 1 watt RED Luxeons. Mitsubishi has just released commercial panels using Luxeons, but not as bright:
http://www.lumileds.com/newsandevents/releases/Dec_04_2002_Mitsu_PR.pdf
However, at this point in time, you could generate the same amount of backlight for about 1/2 the electrical power with CCFL tubes.
For the Luxeons, you can order any that they have from http://www.future-active.com/ . They are the official distributor for the product.
Babyface:
Sweet! Thanks! 🙂
Alvaius: I guess I'm not looking for a huge number of NITS, in fact I don't even know what standards are for that number. Do you not think a row of high-output LED's would work Alvaius? It's simple, it's cheap, and I think it could work. Why would you agree/disagree?
Thanks.
--Clint
Sweet! Thanks! 🙂
Alvaius: I guess I'm not looking for a huge number of NITS, in fact I don't even know what standards are for that number. Do you not think a row of high-output LED's would work Alvaius? It's simple, it's cheap, and I think it could work. Why would you agree/disagree?
Thanks.
--Clint
Hey Clint
Get on with it. Life is full of people who tell you this wont work or that wont work. Maybe he is right but you are not going to risk a lot of dollars. People who make progress are always people who try things. Half the things I make come unstuck but quite a few work very well like my 50 ton wood splitter. Cuts anything.
Go for it. If you don't someone else will.
Good luck
Get on with it. Life is full of people who tell you this wont work or that wont work. Maybe he is right but you are not going to risk a lot of dollars. People who make progress are always people who try things. Half the things I make come unstuck but quite a few work very well like my 50 ton wood splitter. Cuts anything.
Go for it. If you don't someone else will.
Good luck
Thank you for adding absolutely nothing to the conversation Remp. You can take all the shots at me you want, but if you read my post I am not telling people not to do it, just cautioning them on the results. In fact, if you actually read my post I tell how to best produce a backlit LCD using high brightness Luxeon LEDS. I am sorry that it bothers you that I like to prove out concepts on paper before committing time and money. That way I can save the time and money for the ideas that have the best chance of succeeding.
To that end, Han, would it work and be bright enough. That depends on how bright you want your image to be.
For me personally, something on the order of 500 lumens is suitable for a good size image in a dim room. I would like brighter, but I can live with this. Dependent on the LCD, you may be able to get 15% transmissivity. If I had to hazard a guess, taking the backlight efficiency into account, the optics efficiency, etc. I would expect that at best, you would get 50% of the light out that you put in. So, the overall efficiency will be on the order of 0.15*0.5 or 0.075. Light input will need to be at least 500/0.075 or almost 7,000 lumens. For arguments sake, let's say the 1 watt Luxeon's are on there order of 30 lumens (color dependant, but an okay average). You would need on the order of 200 of them. You could use the 5 watt (actually they are exactly 4 times as bright as the 1 watt) and get that number down for at least the green and blue portion.
In my mind, the minimum brightness that would be acceptable, and this is way on the low end would be 200 lumens, so you could get by with say 80 or so 1 watt units. Those 1 watt LEDS are at least 5 times as bright as any 5mm superbright LED that I am aware of. You can use pulsed operation to get higher perceived brightness, but it is my experience that the superbright LEDS can not actually be run with a high maximum pulse current. You can do it, and it will work, but it will actually very quickly degrade the LED in an application like this where it is run continually. So of those 5mm superbrights, to get good brightness you would require on the order of at least 400 and possibly more like a thousand of them. That sounds like a lot, but I think my math is accurate and I have seen backlights (pre Lumileds) that used on the order of that many LEDS to achieve a solid state, daylight readable backlight for a standard 15" or so panel.
200 of a $10 LED may seem like a lot of dollars, but on a per hour basis, you are looking at 4 cents an hour versus 15 cents for a typical bulb. Of course if you were buying those LEDS in volume, the cost would come down.
I would also be very careful using the white 5mm LEDS. The interaction of the heat from the die, the phospor, and the epoxy tends to degrade the output quite quickly compared to non-white LEDS. I have seen on the order of down 30% at only 10,000 hours and accompanied by a significant change in the color of the output. You are much better off mixing Red, Green, and Blue LEDS for both life time, and then you can control the color temperature of the back light.
Alvaius
To that end, Han, would it work and be bright enough. That depends on how bright you want your image to be.
For me personally, something on the order of 500 lumens is suitable for a good size image in a dim room. I would like brighter, but I can live with this. Dependent on the LCD, you may be able to get 15% transmissivity. If I had to hazard a guess, taking the backlight efficiency into account, the optics efficiency, etc. I would expect that at best, you would get 50% of the light out that you put in. So, the overall efficiency will be on the order of 0.15*0.5 or 0.075. Light input will need to be at least 500/0.075 or almost 7,000 lumens. For arguments sake, let's say the 1 watt Luxeon's are on there order of 30 lumens (color dependant, but an okay average). You would need on the order of 200 of them. You could use the 5 watt (actually they are exactly 4 times as bright as the 1 watt) and get that number down for at least the green and blue portion.
In my mind, the minimum brightness that would be acceptable, and this is way on the low end would be 200 lumens, so you could get by with say 80 or so 1 watt units. Those 1 watt LEDS are at least 5 times as bright as any 5mm superbright LED that I am aware of. You can use pulsed operation to get higher perceived brightness, but it is my experience that the superbright LEDS can not actually be run with a high maximum pulse current. You can do it, and it will work, but it will actually very quickly degrade the LED in an application like this where it is run continually. So of those 5mm superbrights, to get good brightness you would require on the order of at least 400 and possibly more like a thousand of them. That sounds like a lot, but I think my math is accurate and I have seen backlights (pre Lumileds) that used on the order of that many LEDS to achieve a solid state, daylight readable backlight for a standard 15" or so panel.
200 of a $10 LED may seem like a lot of dollars, but on a per hour basis, you are looking at 4 cents an hour versus 15 cents for a typical bulb. Of course if you were buying those LEDS in volume, the cost would come down.
I would also be very careful using the white 5mm LEDS. The interaction of the heat from the die, the phospor, and the epoxy tends to degrade the output quite quickly compared to non-white LEDS. I have seen on the order of down 30% at only 10,000 hours and accompanied by a significant change in the color of the output. You are much better off mixing Red, Green, and Blue LEDS for both life time, and then you can control the color temperature of the back light.
Alvaius
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