Hi everyone, just wanted to state this "idea" to get comments...
I have an infocus PanelBook 550, and was thinking of:
Using a custom housing (Probably made out of something like wood), a 300W Halogen lamp (With a good ventilation system, maybe 2 or 3 computer fans, the type that are use for Athlon XP or something), and something like a plano/convex lense or a positive meniscus(With about 400-500mm focal length). That would be cheap but I'm not sure of how good would the results be...
The idea would be to simple make a long box where the panel fits, place the halogen lamp at about 30cm (12 inch aprox) from the panel, 2 or 3 computer fans at the sides (between the light and the panel) and on the front, a focusing unit made out of a PVC tube with either a convex plano or a positive meniscus lense of about 110cm diameter and 400-500mm focal lense.
This would be somewhat of a side view where:
=O is a 300W halogen
*=computer fan
==0 is a focusing unit
___________
| * | |
|=O | ==0
|____*_|___|_
I have an infocus PanelBook 550, and was thinking of:
Using a custom housing (Probably made out of something like wood), a 300W Halogen lamp (With a good ventilation system, maybe 2 or 3 computer fans, the type that are use for Athlon XP or something), and something like a plano/convex lense or a positive meniscus(With about 400-500mm focal length). That would be cheap but I'm not sure of how good would the results be...
The idea would be to simple make a long box where the panel fits, place the halogen lamp at about 30cm (12 inch aprox) from the panel, 2 or 3 computer fans at the sides (between the light and the panel) and on the front, a focusing unit made out of a PVC tube with either a convex plano or a positive meniscus lense of about 110cm diameter and 400-500mm focal lense.
This would be somewhat of a side view where:
=O is a 300W halogen
*=computer fan
==0 is a focusing unit
___________
| * | |
|=O | ==0
|____*_|___|_
lenses...
You will also need a fresnel lens (OHP style) to focus the light coming through the LCD back onto your objective lens. Without that, you'll get a very dim image with a hot spot in the middle.
Also, you will definitely want to use a doublet lens or better yet a triplet lens as your objective. A meniscus doesn't focus the entire image, especially the corners. I think that if you are looking for an inexpensive setup, then you would probably be happiest using an OHP that uses a 300w lamp because that is essentially what your setup would be after you add in the fresnel and better objective lens. Even if you want to build your own enclosure, it would probably be cheapest to get your parts out of an old OHP if you could find a dead one for $30. If not, I could sell you an enhanced fresnel lens and triplet lens for about $65 plus shipping at www.diylabs.org.
I hope some of this helps you with your project. Happy holidays too!
You will also need a fresnel lens (OHP style) to focus the light coming through the LCD back onto your objective lens. Without that, you'll get a very dim image with a hot spot in the middle.
Also, you will definitely want to use a doublet lens or better yet a triplet lens as your objective. A meniscus doesn't focus the entire image, especially the corners. I think that if you are looking for an inexpensive setup, then you would probably be happiest using an OHP that uses a 300w lamp because that is essentially what your setup would be after you add in the fresnel and better objective lens. Even if you want to build your own enclosure, it would probably be cheapest to get your parts out of an old OHP if you could find a dead one for $30. If not, I could sell you an enhanced fresnel lens and triplet lens for about $65 plus shipping at www.diylabs.org.
I hope some of this helps you with your project. Happy holidays too!
Re: lenses...
Thanks for the help! One question though: I read someplace that one could use two simple fresnels (Sheet magnifiers) placed together by their back sides. Is that correct? If yes, then what would be a sheet magnifiers "back side"? If no, what is exactly the "enhanced fresnel lense" you can sell me?
Thanks again and merry christmas
diylabs said:
Thanks for the help! One question though: I read someplace that one could use two simple fresnels (Sheet magnifiers) placed together by their back sides. Is that correct? If yes, then what would be a sheet magnifiers "back side"? If no, what is exactly the "enhanced fresnel lense" you can sell me?
Thanks again and merry christmas
It is possible to use two sheet magnifiers, but the ones that I have tried have the wrong focal length to work with most objective lenses, which means that you'll be losing light if you use those because much of the light will shoot past your objective lens.
You can use any OHP lens. The only thing that makes my fresnel "enhanced" is that the rear half uses a shorter focal length so that you can place the light source closer, giving you a brighter picture.
With any fresnel lens that you chose, the side with the grooves should always face towards the LCD panel. The number of grooves per inch doesn't really matter here as long as you place the fresnel lenses about half an inch from the LCD panel - otherwise you will see the grooves in your projection!
You can use any OHP lens. The only thing that makes my fresnel "enhanced" is that the rear half uses a shorter focal length so that you can place the light source closer, giving you a brighter picture.
With any fresnel lens that you chose, the side with the grooves should always face towards the LCD panel. The number of grooves per inch doesn't really matter here as long as you place the fresnel lenses about half an inch from the LCD panel - otherwise you will see the grooves in your projection!
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