hey guys,
the problem with one way glass is that it will not let the light pass through to the reflective side. if the light were coming from the reflective side it would go through to the non reflective side but seem its the other way around.., well yeh..... please note that i mean not to use a light behind the lcd but behind the glass, so im not pulling apart my lcd.
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Jake
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the problem with one way glass is that it will not let the light pass through to the reflective side. if the light were coming from the reflective side it would go through to the non reflective side but seem its the other way around.., well yeh..... please note that i mean not to use a light behind the lcd but behind the glass, so im not pulling apart my lcd.
____
Jake
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Epidiascope
You used to get a device called an Epidiascope . You could place any printed material underneath it and it would project that image on the wall. They required powerfull lightsources and large and bulky optics . The projected image from these devices were always dull and faint . Epidiascopes were replaced by OHP even though you had to use transparencies and special pens etc.
OHP were much brighter and clearer.
Your idea will work but you WILL lose colour saturation and contrast. Why waste an LCD on this project any monitor or TV
will work just as bad.
You used to get a device called an Epidiascope . You could place any printed material underneath it and it would project that image on the wall. They required powerfull lightsources and large and bulky optics . The projected image from these devices were always dull and faint . Epidiascopes were replaced by OHP even though you had to use transparencies and special pens etc.
OHP were much brighter and clearer.
Your idea will work but you WILL lose colour saturation and contrast. Why waste an LCD on this project any monitor or TV
will work just as bad.
I have seen some schematics about the epidiascope, and I think this project will not work in the same way.
In the epidiascope you put a REAL object under the light and then you collect the light which reflects from this with a lens that project it. With this project the REAL item is substituted with the image projected onto the mirror, this image for example will not reflect the light in the same way a photo (made of paper) will. If you put a green object under a light the light which reflect from this is a green light, I could be wrong but I think that the light that reflects from the mirror where the image is projected will not be the same colour of the image, it will be simply a white light, so the only thing you obtain is a lighter image.
Finally corwes is right, why use an lcd, this project will work in the same way with a standard tv.
In the epidiascope you put a REAL object under the light and then you collect the light which reflects from this with a lens that project it. With this project the REAL item is substituted with the image projected onto the mirror, this image for example will not reflect the light in the same way a photo (made of paper) will. If you put a green object under a light the light which reflect from this is a green light, I could be wrong but I think that the light that reflects from the mirror where the image is projected will not be the same colour of the image, it will be simply a white light, so the only thing you obtain is a lighter image.
Finally corwes is right, why use an lcd, this project will work in the same way with a standard tv.
I was Searching Someone with this Idea
Hi Jake,
I have a Laptop with 15" Monitor
and i want to use Reflective Kind of
DIY projector with Laptop screen
for teaching purpose in class room
I would like to know results of ur
experiment. May be a picture or two
would be helpful to get the Idea how
it worked
Thanks
Hi Jake,
I have a Laptop with 15" Monitor
and i want to use Reflective Kind of
DIY projector with Laptop screen
for teaching purpose in class room
I would like to know results of ur
experiment. May be a picture or two
would be helpful to get the Idea how
it worked
Thanks
you can buy a real beamsplitter at www.sciplus.com for $25 bucks.It's 14-1/4 X 35-3/8 the descpriction says it reflects approx. 50% light.
Argh... as someone already told this idea has no potential of working well. First of all the original image will be weakened when it is reflected from the glass (loss of the light of the original real projection, contrast and so on), and secondly if you add light after the actual projection which happens on the point of the LCD, the added light will only be added light. You'll get the exact same result by lighting the room, screen or the wall directly, and come on, we are all doing exactly opposite, we darken the room as much as we can to gain better image, not light it up.
You cannot project images from projected images, god damn get real
LOL
Regards
HB
You cannot project images from projected images, god damn get real
LOLRegards
HB
Henry Braithwai,
You seem to have no idea what-so-ever as to what we are aiming to achieve here. We are not projecting a projected image. We are projecting a reflected image. We have a piece of glass on an angle over the top of an lcd and have the light shining through the piece of glass. Now what part of the glass over the lcd in projecting? NONE! It is reflecting, not projecting.
Jake
You seem to have no idea what-so-ever as to what we are aiming to achieve here. We are not projecting a projected image. We are projecting a reflected image. We have a piece of glass on an angle over the top of an lcd and have the light shining through the piece of glass. Now what part of the glass over the lcd in projecting? NONE! It is reflecting, not projecting.
Jake
jake: yes, I have understood exactly right what you are trying to achieve. How hard is it to see that what you are doing is actually just illuminating more the screen? The end result will be absolutely the same if you'd project the image normally to the screen (minus some contrast and colors cause you are reflecting the original image with something that does not work as well as a real mirror (which also would cause some loss in the original image quality)) and then illuminate the screen with external light source. It does not matter if you place the external light behind some glass which is been used to reflect the original projected light or not, the final image will have just worse contrast, image quality and washed out whiter colors because your screen is illuminated.
Regards
HB
Regards
HB
Actually there is one way to do something that is near this idea in the beginning of this thread that would work, but that way would be kind of a hard way...
You could put some kind of a "phosphorised" sheet instead of the mirror, and the you'd project the image on that sheet. So you'd have a real image on the sheet, and that could be used for projecting purposes. The problem would be that you'd have to have optics correcting the angles and such so the image would remane sharp and focused, and of course that I don't know if there is some see trough material that has kind of phospor coat needed in this application... The sheet should be something that will "remember" the image and is responsive enough (such if you'd shut of the projectors light the image will remain on the sheet only for a few milliseconds) and of course is transparent all the time...
Ei edes työlästä...
Regards
HB
You could put some kind of a "phosphorised" sheet instead of the mirror, and the you'd project the image on that sheet. So you'd have a real image on the sheet, and that could be used for projecting purposes. The problem would be that you'd have to have optics correcting the angles and such so the image would remane sharp and focused, and of course that I don't know if there is some see trough material that has kind of phospor coat needed in this application... The sheet should be something that will "remember" the image and is responsive enough (such if you'd shut of the projectors light the image will remain on the sheet only for a few milliseconds) and of course is transparent all the time...
Ei edes työlästä...
Regards
HB
Whoever is actually trying this method of projector, maybe this will be of help to you.
http://sales.goldmine-elec.com/prodinfo.asp?prodid=7953
I stumbled across it looking for some other parts, don't know if it will work for what you want or not. Worth a look, though.
http://sales.goldmine-elec.com/prodinfo.asp?prodid=7953
I stumbled across it looking for some other parts, don't know if it will work for what you want or not. Worth a look, though.
http://sales.goldmine-elec.com/prodinfo.asp?prodid=8779
Turns out the glass is on sale ($1.99 vs. $9.95)
Turns out the glass is on sale ($1.99 vs. $9.95)
what your proposing seems to defy basic physics. light can not filter white light. unless you know of some "magic mirror" that would do as you propose this would be impossible. As far as phospherous, from what i know , the colors are fixed, and glow when excited by radiation, not, necassarily, of the same color that they will emmit.
anyways if you do come up with such a mirror (unpixelated) i'll consider buying you all the projectors you want in exchange for the exclusive rights to your discovery lol
anyways if you do come up with such a mirror (unpixelated) i'll consider buying you all the projectors you want in exchange for the exclusive rights to your discovery lol
Sorry perseus,
I think I would never sell the rights to anything except for big $. I have just found out it is going to be hard to mount my lcd so I am going to investigate this idea thoroughly. I will try and come up with some sort of solution. What I need for my idea to work is something that reflects as well as lets light pass through it.
____
Jake
____
I think I would never sell the rights to anything except for big $. I have just found out it is going to be hard to mount my lcd so I am going to investigate this idea thoroughly. I will try and come up with some sort of solution. What I need for my idea to work is something that reflects as well as lets light pass through it.
____
Jake
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jake said:
Well... just grab a book about optics and read few chapters of basic stuff... I am sure that if you understand what you are reading then you dont even have to do any experiments with this stuff.
Cohort found the stuff that you are looking for... the problem is that it will not work anyway. For example with that material that cohort found you will get an image 1. at your ceiling (less than half original brightness/contrast) and 2. another one on the wall (less than half original brightness/contrast). And if you put the light source on the other side of the half-reflective glass of yours you'll have brighter image nro 2 (well and also the 1. will be brighter) and both the 1. and 2. will have just that much more washed out colors and worse contrast depending on how bright this original light source is. That is just how it is and will be. You have to have a real object that you are projecting, it just has to be so, it is basic physics. No reflected or mirrored or what ever image manipulated with optics will do, sorry.
HB
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