Jake,
Check out this link:
http://neasia.nikkeibp.com/wcs/leafCID=onair/asabt/news/27547
Hezz
Also this one:
http://www.mobilemag.com/content/100/102/C2196/
The first link may not work because the forum program trunkates it.
Check out this link:
http://neasia.nikkeibp.com/wcs/leafCID=onair/asabt/news/27547
Hezz
Also this one:
http://www.mobilemag.com/content/100/102/C2196/
The first link may not work because the forum program trunkates it.
Jake,
A reflective LCD does not look any different from a casual observation that a transmissive.
There are three kinds of LCD panels manufactured at this point in time. They are transmissive types which are the ones used for desk top monitors. And then there are reflective types which are the kind used on the Nintendo game boy. They use light from the front from the sun or light in a room and have no back light. This is done to conserve power because the back light uses a lot of battery power.
There are some new types that are a hybrid of transmissive and reflective which are intended to make it possible for extended battery life in future notebook computers.
I believe there are some larger type reflective panels manufactured for use in industrial applications but they are likely to be hybrids for use in locations where a super bright monitor is needed. Likely they would cost more than then a standard desktop monitor.
If you are using a small LCD monitor no more than 5 inches as I thought you stated in previous posts and can not mount it raw because of the housing layout you might consider just cutting off the back plactic housing and making a longer trapazoidal light pipe out of reflective material. You can then use a brighter bulb and place the LCD close to a Fujinon or Delta lens with out a fresnel. This will give you the best possible redition of the LCD panel for the least amount of money.
Hezz
A reflective LCD does not look any different from a casual observation that a transmissive.
There are three kinds of LCD panels manufactured at this point in time. They are transmissive types which are the ones used for desk top monitors. And then there are reflective types which are the kind used on the Nintendo game boy. They use light from the front from the sun or light in a room and have no back light. This is done to conserve power because the back light uses a lot of battery power.
There are some new types that are a hybrid of transmissive and reflective which are intended to make it possible for extended battery life in future notebook computers.
I believe there are some larger type reflective panels manufactured for use in industrial applications but they are likely to be hybrids for use in locations where a super bright monitor is needed. Likely they would cost more than then a standard desktop monitor.
If you are using a small LCD monitor no more than 5 inches as I thought you stated in previous posts and can not mount it raw because of the housing layout you might consider just cutting off the back plactic housing and making a longer trapazoidal light pipe out of reflective material. You can then use a brighter bulb and place the LCD close to a Fujinon or Delta lens with out a fresnel. This will give you the best possible redition of the LCD panel for the least amount of money.
Hezz
i have ade a new discovery. i think these are called artograph projector or something where u place the thging on top and it projects it. it looks like a standard projector witha lid on top. I belive thisidea has come up b4 but ppl say it has been unsuccessful. maybe it caus they dont use lights pointing @ mirrors mounted on the side . oh well just an idea.
oh yeh ad if this doesnt work then ill just have to put it into a custom-built, double sided picture frame.
____
Jake
____
oh yeh ad if this doesnt work then ill just have to put it into a custom-built, double sided picture frame.
____
Jake
____
Attachments
Mixing apples and oranges?
Apples might work!
No, Oranges don't work.
I understand the concept of my apple and I think it will work.
I looked at the picture of your orange and the design is fundamentally flawed.
You don't understand my apple drawing.
Well, orange squared y cos theta > orange prime, so it won't work.
Oh, yeah, There's a patent on a similar apple.
What does that have to do with you orange?
Well the big boys use apples!
Stop acting like a three year old!
If you don't understand it, stop butting in!
Nya! Nya!
---------------------------------------------------------------------------
OK, we had an initial picture that was worth less than a thousand words to start with. It was misunderstood.
Let me make sure that I understand what you are trying to do:
--Bounce light off of an LCD panel and have it end up on a screen, right?
--No light gets to the screen without bouncing off of the LCD panel. right?
Let's follow the light:
--All of the light we are going to shoot onto the screen will start from either a bulb or the backlight on the LCD, right?
--Light goes from the bulb bounces off of some half-reflective surface, illuminates the LCD panel, then goes through the half-reflective panel, through a lens and onto a screen, right?
--None of the light from the bulb gets to the screen without bouncing off of the LCD panel (and going through it twice, once in and once out), right?
And check a few premises:
--Polarization has nothing to do with this working, outside of the polarization that occurs inside of the panel, right?
--The very first picture shown in this thread had the mirror in an unworkable position (rotated 90 degrees from workable), right?
--The mirror doesn't have any intelligence or moving parts or circuitry (like a DLP mirror), right?
--If you took away the LCD panel from th design and replaced it with, say, a magazine page, it would work essentially the same way, right?
And add a bit of conjecture:
--You really just want to shine a bright light on the LCD panel (regardless of any mirrors employed or not) and get it through a lens and onto a screen, right?
--The use of the mirror is so that the light can enter and exit the LCD panel perpendicularly to its surface, right?
And wrap up with a couple of suggestions:
--When you make a drawing, draw at least one ray of light following the path from the lamp to the screen. (With all of the bounces in between)
--Take your LCD panel outdoors on a sunny day (while connected to a signal and power source) and see if the sunlight makes the image on your LCD panel bright with saturated colors or simply washed out and 100% unviewable.
--Lacking the above, just aim a flashlight at your screen. Do you get a bright circle of picture, or a bright circle of glare on the surface from it?
--See how long it takes for the panel to get warm to the touch. (These things have problems startimg at about 100 degrees F. --Human body temperature. Therefore if it feels warm, that's too much light energy landing on it.)
--If you want to use the panel as reflective, you'll need to either start with a reflective panel, or dissassemble the transmissive panel and put something reflective in the back of it. You will get SOME reflection out of the light source assembly, but not much.
All of the questions above (that ended with the word "right") are being presupposed by me here. If any of them are not true, let me know.
Once you have responded to this, I can show you how to greatly simplify the design of this thing.
But we need to be talking about the same fruit here.
Apples might work!
No, Oranges don't work.
I understand the concept of my apple and I think it will work.
I looked at the picture of your orange and the design is fundamentally flawed.
You don't understand my apple drawing.
Well, orange squared y cos theta > orange prime, so it won't work.
Oh, yeah, There's a patent on a similar apple.
What does that have to do with you orange?
Well the big boys use apples!
Stop acting like a three year old!
If you don't understand it, stop butting in!
Nya! Nya!
---------------------------------------------------------------------------
OK, we had an initial picture that was worth less than a thousand words to start with. It was misunderstood.
Let me make sure that I understand what you are trying to do:
--Bounce light off of an LCD panel and have it end up on a screen, right?
--No light gets to the screen without bouncing off of the LCD panel. right?
Let's follow the light:
--All of the light we are going to shoot onto the screen will start from either a bulb or the backlight on the LCD, right?
--Light goes from the bulb bounces off of some half-reflective surface, illuminates the LCD panel, then goes through the half-reflective panel, through a lens and onto a screen, right?
--None of the light from the bulb gets to the screen without bouncing off of the LCD panel (and going through it twice, once in and once out), right?
And check a few premises:
--Polarization has nothing to do with this working, outside of the polarization that occurs inside of the panel, right?
--The very first picture shown in this thread had the mirror in an unworkable position (rotated 90 degrees from workable), right?
--The mirror doesn't have any intelligence or moving parts or circuitry (like a DLP mirror), right?
--If you took away the LCD panel from th design and replaced it with, say, a magazine page, it would work essentially the same way, right?
And add a bit of conjecture:
--You really just want to shine a bright light on the LCD panel (regardless of any mirrors employed or not) and get it through a lens and onto a screen, right?
--The use of the mirror is so that the light can enter and exit the LCD panel perpendicularly to its surface, right?
And wrap up with a couple of suggestions:
--When you make a drawing, draw at least one ray of light following the path from the lamp to the screen. (With all of the bounces in between)
--Take your LCD panel outdoors on a sunny day (while connected to a signal and power source) and see if the sunlight makes the image on your LCD panel bright with saturated colors or simply washed out and 100% unviewable.
--Lacking the above, just aim a flashlight at your screen. Do you get a bright circle of picture, or a bright circle of glare on the surface from it?
--See how long it takes for the panel to get warm to the touch. (These things have problems startimg at about 100 degrees F. --Human body temperature. Therefore if it feels warm, that's too much light energy landing on it.)
--If you want to use the panel as reflective, you'll need to either start with a reflective panel, or dissassemble the transmissive panel and put something reflective in the back of it. You will get SOME reflection out of the light source assembly, but not much.
All of the questions above (that ended with the word "right") are being presupposed by me here. If any of them are not true, let me know.
Once you have responded to this, I can show you how to greatly simplify the design of this thing.
But we need to be talking about the same fruit here.
neededandwanted
heya buddy, how the hell are ya? long time no see and welcome back, not sure if you remeber me or not, but the last time we saw each other was just before easter talking all about light, anyway im interested in this new simplified design u have for a research basis, do u mind sharing it with us?
Thanks and all the best
Trev
heya buddy, how the hell are ya? long time no see and welcome back, not sure if you remeber me or not, but the last time we saw each other was just before easter talking all about light, anyway im interested in this new simplified design u have for a research basis, do u mind sharing it with us?
Thanks and all the best
Trev
Ace!
Definitely remember you!
As far as a simplified design, I first need to be sure of what Jake is trying to do here.
I will pretty much guarantee that we won't need any half-silvered mirrors, though.
If the idea is really just "shine a light on an LCD and put a lens between the LCD and a screen somewhere" then it can be done very simply.
The experiment still needs to be done though. Shine a light on an LCD panel and see if you can make a bright IMAGE, not just a bright glare on the screen.
If it is a point source light (like the sun), we only need a bright image in the center of the screen. Collimating the light out into parallel rays can even out the sweet spot to cover the whole screen.
If all you get is glare (pretty likely) we will need to add one element to the experiment: a sheet of polarizing film.
Basically, only light which is polarized diagonally to the screen (like from corner to corner) is going to make it in and backout of the whole panel. Light polarized the wrong way will be wasted in two ways: [1] as heat, since it will be absorbed into the panel and heat it up and [2] as an "early" reflection--that is, it will reflect before it goes through the panel.
[1] above will just cook the panel and [2] above will just make glare.
If you have access to a sheet of polarized film, just hold it between the panel and light source and rotate it until the glare is at a minimum.
One likely problem though: if the colored filters are reflective, this may cause glare. This is one different between a panel made to be reflective and one that is designed to be transmissive. In a transmissive panel the light can go through actual LC twist and then through the colored filters. In a reflective panel, the colored filters sound be on the far side of the panel, meaning on the other side of the LC twist.
Am I making this confusing?
Let me know and I can clarify.
Having not attempted this with a panel, I don't know how much unfiltered reflection will occur. My guess is that the unwanted reflection is going to drive the contrast level so low that this scheme will be unworkable.
I hate to say that someone's bright idea won't work. In fact I'm still rooting for the "lots of white LEDs" guys and the "hi intensity flourescent" guys.
I have seen a lot of apparent "cheats" here though. People keep coming up with ideas that involve taking white light and passing it through extra colored filters and trying to send it through 3 panels and such. Many of these ideas LOOK like what is happening in commercial units, but this is only an apparency. Really there ain't know way to add filters and get more light (think about it--all a filter can do is waste light).
There are so many points in the light path that subtract light, we need systems that add light.
Outside of DLP's and CRT's the closest we are getting is a backless LCD monitor with a ton of light pushed through it as parallel as possible. An efficient screen can help a bunch, too.
Definitely remember you!
As far as a simplified design, I first need to be sure of what Jake is trying to do here.
I will pretty much guarantee that we won't need any half-silvered mirrors, though.
If the idea is really just "shine a light on an LCD and put a lens between the LCD and a screen somewhere" then it can be done very simply.
The experiment still needs to be done though. Shine a light on an LCD panel and see if you can make a bright IMAGE, not just a bright glare on the screen.
If it is a point source light (like the sun), we only need a bright image in the center of the screen. Collimating the light out into parallel rays can even out the sweet spot to cover the whole screen.
If all you get is glare (pretty likely) we will need to add one element to the experiment: a sheet of polarizing film.
Basically, only light which is polarized diagonally to the screen (like from corner to corner) is going to make it in and backout of the whole panel. Light polarized the wrong way will be wasted in two ways: [1] as heat, since it will be absorbed into the panel and heat it up and [2] as an "early" reflection--that is, it will reflect before it goes through the panel.
[1] above will just cook the panel and [2] above will just make glare.
If you have access to a sheet of polarized film, just hold it between the panel and light source and rotate it until the glare is at a minimum.
One likely problem though: if the colored filters are reflective, this may cause glare. This is one different between a panel made to be reflective and one that is designed to be transmissive. In a transmissive panel the light can go through actual LC twist and then through the colored filters. In a reflective panel, the colored filters sound be on the far side of the panel, meaning on the other side of the LC twist.
Am I making this confusing?
Let me know and I can clarify.
Having not attempted this with a panel, I don't know how much unfiltered reflection will occur. My guess is that the unwanted reflection is going to drive the contrast level so low that this scheme will be unworkable.
I hate to say that someone's bright idea won't work. In fact I'm still rooting for the "lots of white LEDs" guys and the "hi intensity flourescent" guys.
I have seen a lot of apparent "cheats" here though. People keep coming up with ideas that involve taking white light and passing it through extra colored filters and trying to send it through 3 panels and such. Many of these ideas LOOK like what is happening in commercial units, but this is only an apparency. Really there ain't know way to add filters and get more light (think about it--all a filter can do is waste light).
There are so many points in the light path that subtract light, we need systems that add light.
Outside of DLP's and CRT's the closest we are getting is a backless LCD monitor with a ton of light pushed through it as parallel as possible. An efficient screen can help a bunch, too.
Heya neededand wanted, ya i agree but what? lol its out of my range, u are dead right in what your saying and i understood it fully, to me in a case of reflective vs transmisive, transmisive wins the deal, because its so much more eficient, reflecting anything u loose light and when u ony get say 10% at best through a lcd normally having a mirror behind it will almost blank that image out as the light has to go through the lcd 2x not even counting the minimal loses in the mirror film or mirror but also the optics too, ive seen reflective lcd's at where i worked in australia, typically they are used on machines or pda's where they will not be drowned out by the ambient light in the environment, the only reflective method i think is great is dlp, its so eficient but yet more complicated in lining up the light source to the surface and controlling of the colour wheel, i read about that a while ago and its very strict timmings i might add, like if u just wanted to show the colour red, then the mirrors on the dlp chip would be in the on position meaning they would reflect light, so if u just wanted red colour to show, the mirrors would turn on and off every time the red would come around on the wheel, so red is in the light path the chip turns the mirrors on and as the red leaves the light the chip turns the mirrors off again, now with a colour wheel spinning at say 2000rpm that a fast strict timing, im not sure how fast the colour wheel does spin but ive been told it quite fast, and this is just to show the colour red, now what about a dfifferent colour that isnt on the clour wheel? the colours then have the be mixed so the chip even runs faster to mix those colours, just imagine how much data and how fast thos mirrors actually move during a movie scene, wow fast gear and out of my programing skills, anyway i think what jake wants to do here is just make somthing like a artograph, thats the principle, somthing where he can reflect light off of the lcd onto the wall, anyway bud id like to get in contact with you for a chat somtime via email, i dont have yours so if possible can u email me?
Thanks
Trev
http://www.jvcdig.com/SPIEAeroSense04-03revGC.pdf
Hmmm i want one lol thats another type of reflective lcd
Trev
Hmmm i want one lol thats another type of reflective lcd
Trev
reflective panel losses ain't so bad
As far as the losses incurred by going throught the same apnel twice, it's not really that bad because most of the reasons for loss don't get doubled go through the second time.
Big loss - the color filters: Shine white light through a red filter and you lose 2/3 of it (all of the green and blue) in a 100% efficient system. Take the resulting red light and send it back through the same red filter and (theoretically) you lose nothing, because all of the green and blue is already gone. Whatever red light passed through the first time should pass through a second time without any problems.
Big loss - polarization: When unpolarized light is sent through the first time, half of it gets absorbed (at least) . When it comes back through it is in the correct alignment to pass through with no additional loss.
Big loss - the "screen" : Whe the light goes through the first time a lot of it hits the spaces in between the pixels (the "screen" as in "screen door") . If a well-aligned mirror is on the back, any light that made it through a "hole" will come back out through the same hole.
It is even possibly to have TWO LCD panels, perfectly aligned, in a sandwich. The light goes through the first one, then through the second one. The loss through the second panel is very small. You can use an arrangement like this to boost the contrast ratio through the roof.
It would be worth trying with 2 panels made for OHP, which have bad contrast (mostly due to being designed and built at least 10 years ago).
Two well-aligned panels each having a contrast ratio of only 30 to 1, would have a theoretical contrast ration of 900 to 1 in a sandwich like this.
(You would need to remove or at least rotate some of the polarizing films.)
Why wasn't this done by the big manufacturers? Two panels would be twice as expensive.
Why isn't this done by DIYers? You would need two TOTALY identical panels to get the spacing lined up perfectly. You would need a totally parallel light source (usually lens before and lens after the panels). You also need to drive two monitors from one source with tight timing precision.
There are lots of possible variations on this. One of the most interesting is to use an monochrome monitor and color monitor sandwiched together. The mono monitor would simply increase contrast by modulating the white light before it gets to the color panel.
If we ever get strong enough LED's, it would even be possible to modulate the light before the panels, so a dark scene wouldn't need to be a gray scene. With the correct driving hardware, the lights could even be modulated based on the signal such that certain areas would be illuminated more than others based on the amount of light that needs to be transmitted by THAT area of panel. Basically, you would have a monochrome LED display behind a color LCD panel.
As far as the losses incurred by going throught the same apnel twice, it's not really that bad because most of the reasons for loss don't get doubled go through the second time.
Big loss - the color filters: Shine white light through a red filter and you lose 2/3 of it (all of the green and blue) in a 100% efficient system. Take the resulting red light and send it back through the same red filter and (theoretically) you lose nothing, because all of the green and blue is already gone. Whatever red light passed through the first time should pass through a second time without any problems.
Big loss - polarization: When unpolarized light is sent through the first time, half of it gets absorbed (at least) . When it comes back through it is in the correct alignment to pass through with no additional loss.
Big loss - the "screen" : Whe the light goes through the first time a lot of it hits the spaces in between the pixels (the "screen" as in "screen door") . If a well-aligned mirror is on the back, any light that made it through a "hole" will come back out through the same hole.
It is even possibly to have TWO LCD panels, perfectly aligned, in a sandwich. The light goes through the first one, then through the second one. The loss through the second panel is very small. You can use an arrangement like this to boost the contrast ratio through the roof.
It would be worth trying with 2 panels made for OHP, which have bad contrast (mostly due to being designed and built at least 10 years ago).
Two well-aligned panels each having a contrast ratio of only 30 to 1, would have a theoretical contrast ration of 900 to 1 in a sandwich like this.
(You would need to remove or at least rotate some of the polarizing films.)
Why wasn't this done by the big manufacturers? Two panels would be twice as expensive.
Why isn't this done by DIYers? You would need two TOTALY identical panels to get the spacing lined up perfectly. You would need a totally parallel light source (usually lens before and lens after the panels). You also need to drive two monitors from one source with tight timing precision.
There are lots of possible variations on this. One of the most interesting is to use an monochrome monitor and color monitor sandwiched together. The mono monitor would simply increase contrast by modulating the white light before it gets to the color panel.
If we ever get strong enough LED's, it would even be possible to modulate the light before the panels, so a dark scene wouldn't need to be a gray scene. With the correct driving hardware, the lights could even be modulated based on the signal such that certain areas would be illuminated more than others based on the amount of light that needs to be transmitted by THAT area of panel. Basically, you would have a monochrome LED display behind a color LCD panel.
Epoch "positive" projector
I'm pretty new to the DIY projector realm(about 6 hours for this site). Though I came across a Epoch "positive" projector about a year ago and I had the idea of making it a LCD projector. Just face the lcd monitor down on the "bed" of the projector(similar to a photocopier), and make it "light tight". Is this apples or oranges....or pears....with my luck it will be pears....
? I too was concerned about heat and glare....that's why I never got around to the project honestly. What about cannabilizing my Epoch(I had found info on it when I first got it, but I cant find the site anymore...but I kinda remember it was REALLY expensive in its day....about 2700??)and making a more conventional transmissive design. Any help suggestions would be greatly appreciated.
Thanks for your time......
Nate
I'm pretty new to the DIY projector realm(about 6 hours for this site). Though I came across a Epoch "positive" projector about a year ago and I had the idea of making it a LCD projector. Just face the lcd monitor down on the "bed" of the projector(similar to a photocopier), and make it "light tight". Is this apples or oranges....or pears....with my luck it will be pears....
? I too was concerned about heat and glare....that's why I never got around to the project honestly. What about cannabilizing my Epoch(I had found info on it when I first got it, but I cant find the site anymore...but I kinda remember it was REALLY expensive in its day....about 2700??)and making a more conventional transmissive design. Any help suggestions would be greatly appreciated.Thanks for your time......
Nate
Epoch "positive" projector
I'm pretty new to the DIY projector realm(about 6 hours for this site). Though I came across a Epoch "positive" projector about a year ago and I had the idea of making it a LCD projector. Just face the lcd monitor down on the "bed" of the projector(similar to a photocopier), and make it "light tight". Is this apples or oranges....or pears....with my luck it will be pears....? I too was concerned about heat and glare....that's why I never got around to the project honestly. What about cannabilizing my Epoch(I had found info on it when I first got it, but I cant find the site anymore...but I kinda remember it was REALLY expensive in its day....about 2700??)and making a more conventional transmissive design. Any help suggestions would be greatly appreciated.
Thanks for your time......
Nate
I'm pretty new to the DIY projector realm(about 6 hours for this site). Though I came across a Epoch "positive" projector about a year ago and I had the idea of making it a LCD projector. Just face the lcd monitor down on the "bed" of the projector(similar to a photocopier), and make it "light tight". Is this apples or oranges....or pears....with my luck it will be pears....
? I too was concerned about heat and glare....that's why I never got around to the project honestly. What about cannabilizing my Epoch(I had found info on it when I first got it, but I cant find the site anymore...but I kinda remember it was REALLY expensive in its day....about 2700??)and making a more conventional transmissive design. Any help suggestions would be greatly appreciated.Thanks for your time......
Nate
Well Im not sure where I got Epoch from.....It's actually a Plus DP-30.......
http://www.plus-vision.com/en/product/projector/dp-30/index.html
Halogen bulbs.....that doesnt sound good. Do you think the optics will work though?
Nate
http://www.plus-vision.com/en/product/projector/dp-30/index.html
Halogen bulbs.....that doesnt sound good. Do you think the optics will work though?
Nate
just to be clear, shouldnt the original design in this thread be:
An externally hosted image should be here but it was not working when we last tested it.
yes that is the original idea but those plus projectors work in exactly the same way! they use a mirror and circulate light throughout the "chamber". apparently this brings a wahed out image but the plus projectors dont.
does anyone know why the plus projector works - the only diffence is that i notice the plus projector lamps shine onto mirrors at the side and thats all.
thanks
____
Jake
____
does anyone know why the plus projector works - the only diffence is that i notice the plus projector lamps shine onto mirrors at the side and thats all.
thanks
____
Jake
____
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