Hey, it seems that everyone always has the thought in the back of thier mind weather or not putting two lower contrast LCDs on top of each other would create a higher contrast better image...
Is the reason that people havn't already done this because so much light is taken? if each LCD takes even 50% of the light, your down to only 25% of your original light...
I've just always wondered... plus, it might be cheaper to put multipule cheap LCDs in a row each with lower contrast...
Also, it seems that you would remove some of the screen door effect if you were able to offset each one a tiny bit... maybe not...
Ok... Just seeing if anyone has tried or if they know how this works
Thanx
Is the reason that people havn't already done this because so much light is taken? if each LCD takes even 50% of the light, your down to only 25% of your original light...
I've just always wondered... plus, it might be cheaper to put multipule cheap LCDs in a row each with lower contrast...
Also, it seems that you would remove some of the screen door effect if you were able to offset each one a tiny bit... maybe not...
Ok... Just seeing if anyone has tried or if they know how this works
Thanx
From what I hear a lot more than 50 percent of the light gets taken...like 90 percent. Doesn't seem worth it to me, just another LCD to worry about....also, if it had worked good, you'd think that companies that make projectors would have done it by now.
The only reason why I mention is that you can get some pretty low contrast old LCDs for fairly small amounts of $$$
I think that projector componies wouldn't do this because it means that they must fit more electronics in there... they must cool it more... etc... All things that are a major concern for those small portable LCD projectors...
I on the other hand, could care less if I have to put another controller card inside my enclosure... there is plenty of room...
Plus it might be cheaper just to go with a higher contrast LCD... but I already have an LCD so it is much cheaper to ... upgrade... by adding an LCD...
Well If I find a cheap enough one, I'll go ahead and try it
I think that projector componies wouldn't do this because it means that they must fit more electronics in there... they must cool it more... etc... All things that are a major concern for those small portable LCD projectors...
I on the other hand, could care less if I have to put another controller card inside my enclosure... there is plenty of room...
Plus it might be cheaper just to go with a higher contrast LCD... but I already have an LCD so it is much cheaper to ... upgrade... by adding an LCD...
Well If I find a cheap enough one, I'll go ahead and try it
I know lots of older models did. I think this was to get a higher color depth and contrast, because at the time a single LCD that could achieve the same specs cost a lot. As far as I know LCD projectors use a single LCD now, as LCD's have advanced a ton in color depth and especially in contrast. Also the light transmitting problem, some three LCD projectors were very dim.
So I if I come by a relly cheap LCD, I might as well get it and see how it works? I think I will... If anything, I'll have a second monitor for my comp... which I have been wanting for a while anyway
As for brightness... you could always use multipule lights... one for each LCD... boy would that be enefficient... and expensive... and big... and a really bad idea...
most 3LCD projectors use one for each color though, right, or do they actually just 'stack' them?
As for brightness... you could always use multipule lights... one for each LCD... boy would that be enefficient... and expensive... and big... and a really bad idea...
most 3LCD projectors use one for each color though, right, or do they actually just 'stack' them?
oem lcd projectors use 3 lcd panels to create the image. 1 lcd is old technology, back in the early ans mid-90's.
each one of these lcd panels handles one color, red, blue & green.
the "white" beam of light generated by the lamp passes through a glass sqare/boxy fresnel then through two filters(mirrors) to split the beam into three colors, red, blue & green. this colored light passes through the monochrome lcd panels and into a prizm where they are combined again and projected to the screen to form the image.
that is basically it. i have taken appart my epson 5500C many times and have cleaned all the mirrors and light filters so i know whats in there. if anyone is interested in seeing detailed pictures i will be willing to take it appart again. i dont use it any more since i got an epson 7500 which is xga.
ap0
each one of these lcd panels handles one color, red, blue & green.
the "white" beam of light generated by the lamp passes through a glass sqare/boxy fresnel then through two filters(mirrors) to split the beam into three colors, red, blue & green. this colored light passes through the monochrome lcd panels and into a prizm where they are combined again and projected to the screen to form the image.
that is basically it. i have taken appart my epson 5500C many times and have cleaned all the mirrors and light filters so i know whats in there. if anyone is interested in seeing detailed pictures i will be willing to take it appart again. i dont use it any more since i got an epson 7500 which is xga.
ap0
Hmmm, thats pretty cool... its too bad we can't get the parts to make one like that ourselfs.... could get some sweet projectors... I bet those are freakin hard to calibrate though... if you made yone yourself I mean... Anyway, there doesn't seem to be much of a black and white LCD demmand...
do you think that if you just used color LCDs instead of b/w ones, and didn't use color splitting glass, You might be able to achieve the higher contrast... would be just as easy to put hem in series though....
cool stuff
do you think that if you just used color LCDs instead of b/w ones, and didn't use color splitting glass, You might be able to achieve the higher contrast... would be just as easy to put hem in series though....
cool stuff
If you got Red, Green, and Blue LCDs, and aligned them correctly, could you just shign the same light souce through all of them in a row?
I think so. They would have to be just that though... they couldn't be b/w ones with color filters or anything like that or only the last color would show.
Not sure where you can get those color of LCDs though... We are kind stuck with what the market produces for other purposes, so must use whats already out there...
Its too bad
Not sure where you can get those color of LCDs though... We are kind stuck with what the market produces for other purposes, so must use whats already out there...
Its too bad
Sometimes surplus sites have 6.4" or 8.4" VGA or sometimes SVGA monochrome(RGB) lcds for $30-$40. I haven't seen any lately, but you see them here and there.
huh... I havn't seen those, but I definately will keep an eye our for them...
If I find a cheap low quality LCD, I will definately try to increase my contrast by layering the two...
I would imagine that even if you layer 2 LCDs, you are only goign to get darker blacks and you will only get whites that are as bright as your darkest white on either of the LCDS... basically you will get the white of the worst LCD... for this reason, I don't think that if you take 2 300:1 LCDa you will get 600:1... maybe something more like 450:1...
I guess we'll see if anyone gets 2 LCDs at once at trys it...
If I find a cheap low quality LCD, I will definately try to increase my contrast by layering the two...
I would imagine that even if you layer 2 LCDs, you are only goign to get darker blacks and you will only get whites that are as bright as your darkest white on either of the LCDS... basically you will get the white of the worst LCD... for this reason, I don't think that if you take 2 300:1 LCDa you will get 600:1... maybe something more like 450:1...
I guess we'll see if anyone gets 2 LCDs at once at trys it...
If I am not mistaken those are special reflective filters that allow only one color of light to pass, the LCDs are probably just regular monochrome but are programmed to only show that colors portion of the image. Is that how it works guys?
CB.
CB.
yes those are reflective filters, the monochrom lcd panels display the same picture in each. this is why convergence is so important. and that is how all the colors (16 million) are created.
ap0
ap0
I took it as he wanted to put all three on top of eachother, which I don't think would work too niftily.
The 3 LCD approach is too much of a project. You'd save both time and money buying a commercial projector if your looking to make this a solution.
1 - you wouldnt save money with lower res panels... you'd end up paying twice as much as a single panel setup.
2- The optics cost at least 3 times as much as a single projector setup. The only way they wouldnt cost an arm and a leg is if you order everything in bulk... which I doubt anyone here is going to do.
3- Most people on the boards fail at building their own projector cases because they dont setup the optics correctly... so they run back to an OHP setup. The 3 LCD approach needs even more optics and colored mirrors positioned at percise angles to get the desired effect. Anyone up for it?
Didnt think so 🙂
1 - you wouldnt save money with lower res panels... you'd end up paying twice as much as a single panel setup.
2- The optics cost at least 3 times as much as a single projector setup. The only way they wouldnt cost an arm and a leg is if you order everything in bulk... which I doubt anyone here is going to do.
3- Most people on the boards fail at building their own projector cases because they dont setup the optics correctly... so they run back to an OHP setup. The 3 LCD approach needs even more optics and colored mirrors positioned at percise angles to get the desired effect. Anyone up for it?
Didnt think so 🙂
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