alvaius said:
Okay, this is the part where I'm a bit unclear.
I thought that with a normal LCD projection panel (such as a NView or, in my existing case, Boxlight), you lost about %10-%15 of the light due to the natural dimness of the LCD glass, and %50 of the light due to the polarization requirement of light passing through the LCD.
Unless I'm mistaken, I thought the purpose of backlight optics was reflect back unpolarized light, rotate it, and send it back through as polarized, usable light. Assuming these are 95% effective, that means we'll lose only %15-%25 of the light going through the panel, as opposed to %60-%65 of the light as in a normal LCD projection panel.
It was for this reason that I wanted to use the polarization optics of a flat-panel monitor, simply because the optics almost double my effective light usage.
Just by holding a fresnel up to my laptop screen I was able to project an image on my screen (granted it sucked because nothing was adjusted properly, but it still worked a.l.a. 100" big-screen TV plans). If we can merely brighten the image by 2x or maybe as much as 6x, it would work very nicely.
I have no idea on the lumen output of CCFT lights, but I know that looking at a high-output LED will make me see spots in my retina, as CCFT's won't really. If we can take the concentrated power of LED's, it seems like we can significantly multiply the effective brightness of the backlight.
This is completely devoid of equations, and is based largely upon what light sources make my eyes hurt. 🙂
I think I am going to take Remp's advice and just ignore the equations for the moment, and go with my gut on this one and have fun with the experiment. It's not so much that I want to watch big-screen movies... I hardly watch TV at all. The whole joy of it for me comes in the theorizing and the debate and the ingenuity and the research and then the actual development. 🙂
My next question for you then, Alvaius, is more of a practical sense. Do I just go RGB, and buy 10,000 mcd LED's of each? Some colors are percieved brighter though, what kind of ratio's would I want with each LED? Like 5/10 is blue, 2/10 is green, 3/10 is red? I've looked at color ramping charts, but I'm not sure how to translate all that into actual, physical LED's with regards to the percieved brightness and other such things.
Thanks for your help Alvaius, it really does give me alot more information and it comes in a way that is very helpful to me. 🙂
Thanks for your help Remp, that was very encouraging and it actually helped persuade me to continue in my LED project, as it's somewhat frustrating at times to pioneer, as we all know. 🙂
I really appreciate this board, I find everyone on here amazing, and it's incredible for me to be able to talk to people of like mind with myself. 🙂 There's something cool about talking with other people who have the same corky interests as yourself... like in dismantling and constructing things and other fun ways to burn off your eyebrows. 🙂
Keep the wheels of innovation turning. 🙂
--Clint
I will ask Lumileds the exact makeup of their proto backlight in terms of RGB leds. I can quickly convert that to lumens per color. From there, you can get an idea of how many LEDS of each color you will need. It is Friday, give me a few days.
Your assumption about the LCD panels are correct, but keep in mind the following:
1) Not 100% of the panel is active, hence you lose some light right off the bat.
2) There are 3 colors in the panel, hence each color only takes up 33% of the active area, however, you are lighting up 100% of the panel. Hence, the maximum transmissivity for any color is 33%. There may be a bit of reflectance when a pixel is off, but for the most part, you are down to 33% right off the bat.
When you take everything into consideration, I think the best panels today are on the order of 20%.
If LCDs were quicker, you could use a monochrome panel and pulse each color, but the best on/off times for the pixels are on the order of 15-20 milliseconds.
Alvaius
Your assumption about the LCD panels are correct, but keep in mind the following:
1) Not 100% of the panel is active, hence you lose some light right off the bat.
2) There are 3 colors in the panel, hence each color only takes up 33% of the active area, however, you are lighting up 100% of the panel. Hence, the maximum transmissivity for any color is 33%. There may be a bit of reflectance when a pixel is off, but for the most part, you are down to 33% right off the bat.
When you take everything into consideration, I think the best panels today are on the order of 20%.
If LCDs were quicker, you could use a monochrome panel and pulse each color, but the best on/off times for the pixels are on the order of 15-20 milliseconds.
Alvaius
alvaius
You see I did not add absolutely nothing to the conversation as you said. In fact I added quite a bit. Its something you have no idea about called enthusiasm and pioneering spirit.
You have stuck to dry no you can't do it facts. As I said you might be right but there is one major factor you have overlooked that of obtaining better use of the light by exploring the use of polarization convertor films, Brightness Enhancement Films and anything else that might push the project along.
These enhancements coupled with the guys natural enthusiasim may bring a result and I for one will be helping whenever they want me.
Yes I will continue to knock your attitude. Its nothing personal, dont get me wrong I would imagine you are a nice guy but there is more to DIY than just the straight out facts. There is that one vital ingredient Having a go. Gaining experience. They dont want your experience, they want their own. Its not really your business to save people time and money. Thats their business. If you can see things in that light your contributions would be more helpful.
You see I did not add absolutely nothing to the conversation as you said. In fact I added quite a bit. Its something you have no idea about called enthusiasm and pioneering spirit.
You have stuck to dry no you can't do it facts. As I said you might be right but there is one major factor you have overlooked that of obtaining better use of the light by exploring the use of polarization convertor films, Brightness Enhancement Films and anything else that might push the project along.
These enhancements coupled with the guys natural enthusiasim may bring a result and I for one will be helping whenever they want me.
Yes I will continue to knock your attitude. Its nothing personal, dont get me wrong I would imagine you are a nice guy but there is more to DIY than just the straight out facts. There is that one vital ingredient Having a go. Gaining experience. They dont want your experience, they want their own. Its not really your business to save people time and money. Thats their business. If you can see things in that light your contributions would be more helpful.
Hi guys and girls🙂
I love read alvaius' and remp's posts.
Now about LEDs as light source for LCD front projectors.
With LCD panel you lost 60-70% of light! Better but expensive way is DLP. Only with reflective LCD-LCoS you can get satisfaction. Just buy HMD cy-visor 4400 or 4500 for $600-800
and dissassemble this thing.
Now you have driver board+light engine+optic+2 LCoS 800x600. Replace existing RGB LEDs to cluster of LuxeonStar, lenses and try... But you need super gain screen like Vutec13x or mocom 10/ 20 gain🙂
Good luck!
PS I hope you understand my english🙂
I love read alvaius' and remp's posts.
Now about LEDs as light source for LCD front projectors.
With LCD panel you lost 60-70% of light! Better but expensive way is DLP. Only with reflective LCD-LCoS you can get satisfaction. Just buy HMD cy-visor 4400 or 4500 for $600-800
and dissassemble this thing.
Now you have driver board+light engine+optic+2 LCoS 800x600. Replace existing RGB LEDs to cluster of LuxeonStar, lenses and try... But you need super gain screen like Vutec13x or mocom 10/ 20 gain🙂
Good luck!
PS I hope you understand my english🙂
Your english is just fine.
DLP would give a big advantage, for two reasons. One is the better light transfer, however, the big advantage is they switch really fast and hence you could pulse three colors of LEDS onto a single DLP panel to achieve full color. That way you don't lose the 2/3 of the light you lose projecting through a full color display.
DLP would give a big advantage, for two reasons. One is the better light transfer, however, the big advantage is they switch really fast and hence you could pulse three colors of LEDS onto a single DLP panel to achieve full color. That way you don't lose the 2/3 of the light you lose projecting through a full color display.
I'm getting tired of Remp. If somebody says, "I don't think that will work", or "that's not a good idea, try this instead", he flames the person, calls them negative, a problem, etc. Saying things like, "you've probably never picked up a soldering iron in your life" is nothing more than childish flaming. Then if you respond to him to defend yourself in any way that might resemble a flame, he'll report you to the moderators.
He acts like he is a moderator because he's been on here for so long. He tells people what kind of attitude they need to have, etc. I don't care how friendly he is w/ the people who started this thing. At the same time personally attcks anyone who HE thinks does not have a positive vision. Then he writes a little speech about how people who take risks and think new things are the ones who get things done. I've seen enough Apple commercials, so I don't need to hear it from him.
There should be no double standards. If he's gonna tell people they need to behave, then he himself at least needs to behave.
I don't think he'll see this because I'm on his ignore list (I hope), but if he does, I garantee you all that he'll report this here post to the moderators (with no merit whatsoever) and respond with personal insults.
I know this is off topic but if he can publicly insult somebody because he personally dissapproves of somebody's opinion on a plan or project, then I can make my point that I don't approve of his lecturing.
It's great to have new ideas and think in new directions, but if somebody thinks something will work and somebody else thinks it won't, that person needs to speak up and not get lectured for it. Otherwise, we'd have people wasting time and money on things for no reason.
He acts like he is a moderator because he's been on here for so long. He tells people what kind of attitude they need to have, etc. I don't care how friendly he is w/ the people who started this thing. At the same time personally attcks anyone who HE thinks does not have a positive vision. Then he writes a little speech about how people who take risks and think new things are the ones who get things done. I've seen enough Apple commercials, so I don't need to hear it from him.
There should be no double standards. If he's gonna tell people they need to behave, then he himself at least needs to behave.
I don't think he'll see this because I'm on his ignore list (I hope), but if he does, I garantee you all that he'll report this here post to the moderators (with no merit whatsoever) and respond with personal insults.
I know this is off topic but if he can publicly insult somebody because he personally dissapproves of somebody's opinion on a plan or project, then I can make my point that I don't approve of his lecturing.
It's great to have new ideas and think in new directions, but if somebody thinks something will work and somebody else thinks it won't, that person needs to speak up and not get lectured for it. Otherwise, we'd have people wasting time and money on things for no reason.
Remp, whether you call it DIY, or you call it commercial engineering, the practices are the same. Learn from what others know and learn from their mistakes and experiences. Work it out on paper first if you can, it is cheaper, easier, and will give you a good idea of the expected results. Most DIYers still want to achieve the best results they can. That does not mean better than what they can buy, just the best they can do with what they have on hand. However, if you know in advance it is not going to work, just like in commercial engineering, you take a step back and look at what else you can do.
I disagree with the people on here not wanting "my" experience. Heck, that is the whole point of coming to a forum like this. To learn and share. I come here to learn from what other people know. If they tell me that something won't work and tell me why, then they have saved me time.
On a technical note, I would expect any LCD you are going to use will have a brightness enhancing film on the front as most high brightness displays in production do. The big loss is the 2/3 loss from it being a full color display.
To quote HanClinto, and I apologize to him for bringing this in, "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?" .... I answered this question.
I think using LEDS for displays is actually commercially viable today for some applications. When you look at the lifetime cost of a projector and the bulbs, I can argue pretty easily that the LEDS are cheaper. The great thing the LEDS give you is complete control over color temperature and a wider color spectrum.
I have a tremendous level of enthusiasm and pioneering spirit. My career has been marked by industry "firsts" and recognized with the odd patent here and there.
Alvaius
I disagree with the people on here not wanting "my" experience. Heck, that is the whole point of coming to a forum like this. To learn and share. I come here to learn from what other people know. If they tell me that something won't work and tell me why, then they have saved me time.
On a technical note, I would expect any LCD you are going to use will have a brightness enhancing film on the front as most high brightness displays in production do. The big loss is the 2/3 loss from it being a full color display.
To quote HanClinto, and I apologize to him for bringing this in, "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?" .... I answered this question.
I think using LEDS for displays is actually commercially viable today for some applications. When you look at the lifetime cost of a projector and the bulbs, I can argue pretty easily that the LEDS are cheaper. The great thing the LEDS give you is complete control over color temperature and a wider color spectrum.
I have a tremendous level of enthusiasm and pioneering spirit. My career has been marked by industry "firsts" and recognized with the odd patent here and there.
Alvaius
From what I am reading, remp is saying "try this! try that! Even though it is not possable due to the laws of phisics, the diy spirit will overcome that small obstical!" Remp... Why don't you try this yourself and waist some money. If it does not work on paper, how can the finished product work. From an engineering standpoint, what you are suggesting is just stupid.
Lifter
I don't think he'll see this because I'm on his ignore list (I hope), but if he does, I garantee you all that he'll report this here post to the moderators (with no merit whatsoever) and respond with personal insults.
Good post. I enjoyed it.
I don't think he'll see this because I'm on his ignore list (I hope), but if he does, I garantee you all that he'll report this here post to the moderators (with no merit whatsoever) and respond with personal insults.
Good post. I enjoyed it.
Why don't you try this yourself and waist some money. If it does not work on paper, how can the finished product work. From an engineering standpoint, what you are suggesting is just stupid.
I have. See my thread on laser projectors. I did a lot of work in that thread. Didn't work as I expected but at least I gained a lot of experience. I have bought test gear and components and lenses and a variety of solid state lasers plus 2 Helium neon gas lasers. I have a double beam 20 MHZ scope. A one ghz frequency counter. Programable pulse generator. Four or 5 precision power supplies. I have enough parts for experimenting with.
From an engineering standpoint, what you are suggesting is just stupid.
Could you eleborate.
I have. See my thread on laser projectors. I did a lot of work in that thread. Didn't work as I expected but at least I gained a lot of experience. I have bought test gear and components and lenses and a variety of solid state lasers plus 2 Helium neon gas lasers. I have a double beam 20 MHZ scope. A one ghz frequency counter. Programable pulse generator. Four or 5 precision power supplies. I have enough parts for experimenting with.
From an engineering standpoint, what you are suggesting is just stupid.
Could you eleborate.
I did not know we were talking about lasers in this thread??? I also have precision power supplies and test gear... i do not see your point. Are you saying you are slightly better then the rest of us?
No way. Far from it.
But if you could clarify
From an engineering standpoint, what you are suggesting is just stupid
But if you could clarify
From an engineering standpoint, what you are suggesting is just stupid
No way. Far from it.
But if you could clarify what I have suggested that is stupid.
From an engineering standpoint, what you are suggesting is just stupid
But if you could clarify what I have suggested that is stupid.
From an engineering standpoint, what you are suggesting is just stupid
Sorry for the double post.
Thats rather lame isn't it.
You make an ascertion that from an engineering standpoint what I am suggesting is just stupid.
But then you won't back up your words with the example.
Thats rather lame isn't it.
You make an ascertion that from an engineering standpoint what I am suggesting is just stupid.
But then you won't back up your words with the example.
Guys, please dont fight🙂
We can delete all messages with attacks and leave only core of this tread? I think all posts must contain real information for all
visiteurs?
More information about Luxeon
http://theledlight.com/pdf/Luxeon/5WStars.pdf
http://theledlight.com/pdf/Luxeon/Technical5W.pdf
Just sea of information 🙂
More
Enjoy!
We can delete all messages with attacks and leave only core of this tread? I think all posts must contain real information for all
visiteurs?
More information about Luxeon
http://theledlight.com/pdf/Luxeon/5WStars.pdf
http://theledlight.com/pdf/Luxeon/Technical5W.pdf
Just sea of information 🙂
More
Enjoy!
Lifter
verbose mustafa
alvaius
quote by hanclinto
Just by holding a fresnel up to my laptop screen I was able to project an image on my screen (granted it sucked because nothing was adjusted properly, but it still worked a.l.a. 100" big-screen TV plans). If we can merely brighten the image by 2x or maybe as much as 6x, it would work very nicely.
Even you guys must be able to read the excitement in his post.
You wouldn't consider giving him any encouragement would you.
Like I did.
Somehow I dont think you will. I will email each of you guys and try and encourage you to be more positive.
Hanclinto
If you could leave your CCFl where it is and just start adding led's one at a time it will tell you how much improvement you can expect.
verbose mustafa
alvaius
quote by hanclinto
Just by holding a fresnel up to my laptop screen I was able to project an image on my screen (granted it sucked because nothing was adjusted properly, but it still worked a.l.a. 100" big-screen TV plans). If we can merely brighten the image by 2x or maybe as much as 6x, it would work very nicely.
Even you guys must be able to read the excitement in his post.
You wouldn't consider giving him any encouragement would you.
Like I did.
Somehow I dont think you will. I will email each of you guys and try and encourage you to be more positive.
Hanclinto
If you could leave your CCFl where it is and just start adding led's one at a time it will tell you how much improvement you can expect.
Remp, I know the exact result of backlight projection. If fact, i was the first to try it and did a post on it. I suggested to do a modified backlight projection unit (MBPU). Clint and I have actually been discussing the pros and cons about this for some time. I know an MBPU is possable as I have reaped the results with one key issue: brightness. The brighness of it is comparable to a 100" tv with fresnel as seen on ebay. It is actually slightly brighter. The quality of my projected image was superb. Using only a 5" lcd screen and delta IV lens, I projected a 6 foot image. Now Clint was already doing much research on the idea of using leds as a light source, so we colaborated and both think it is fully possable however, but there is much research to do before we actually move ahead and make one. I am sure Clint can pull off this task, but what you are telling him, is to go ahead and build a house, with out first making blueprints first. Sure, there are many people in this thread who are telling us the cons of our designs, but without knowing the cons of a design, you will continue to make errors that will cost you time and money later on, that could have been avoided. Would you try to nail a 2" thick piece of wood with a 1" nail?
Now to people who care, i recently contacted a CCFL company, and inqired as to the brighness of an 8" CCFL. They said around 25,000 cd/m2. So we need to figure out a way to double if not triple that number. I am starting to think that useing a CCFL to add on the backlight would be even better than leds. I know of a few sources that sell them around 10-20 bucks, but i am sure they can be sought cheaper. As Clint did say, the leds will blind him and the CCFL will not, but you must remember that an led is a direct light source and a CCFL is not. I am sure we can get results using LEDs though, but it may end up costing more than a CCFL mod. Any thoughts?
Now to people who care, i recently contacted a CCFL company, and inqired as to the brighness of an 8" CCFL. They said around 25,000 cd/m2. So we need to figure out a way to double if not triple that number. I am starting to think that useing a CCFL to add on the backlight would be even better than leds. I know of a few sources that sell them around 10-20 bucks, but i am sure they can be sought cheaper. As Clint did say, the leds will blind him and the CCFL will not, but you must remember that an led is a direct light source and a CCFL is not. I am sure we can get results using LEDs though, but it may end up costing more than a CCFL mod. Any thoughts?
The point is remp, you may have tried to give him encouragement, but doing so you added nothing to the content of this thread. You told him to go for it, with out giveing any reason why this mothod might work. Please, lets just stop arguing, becuse we have aready taken up half this thread with pointless coments.
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