jvisaria,
The plano-convex lens I am using essentially achieves the same thing as using a fresnel. I have substituted a frenel (page magnifier) in its place, and it produced an image very similiar to the PCX. However, in my experience, I have never been able to get a clear image with a fresnel--the quality is much better with the PCX lens. I believe that the image degradation IS because of using a non-point source light, and I think that a fresnel is much better suited or that type of light. There are rays of all different angles striking the fresnel at different points, and this makes the image very washed out. Why are these washing out effects reduced when using the PCX lens? I don't know, but keep in mind that the image quality is NOT perfect.
I also was not successful using a fresnel or PCX to "gather" the image to send it to a Fujinon or Delta lens assembly. I might just be setting it up wrong, but no dice. 😕
CanadianMike,
You are correct in your thinking, but if you are considering removing the back from a computer LCD panel, make sure that all of the driver boards can be moved from the active area. That has been the Achilles heel so far with that approach. In the last month, there have been lots of posts dealing with it, and I believe there has been some success with certain models.
If you wanted to go the easy route, panels made for overhead projectors can be placed on the OHP witout any modification. The quality might not be as high as using an LCD computer panel, but the prices are reasonable. Do a search on Ebay for "projection panel" to get an idea of what is out there.
-f4
The plano-convex lens I am using essentially achieves the same thing as using a fresnel. I have substituted a frenel (page magnifier) in its place, and it produced an image very similiar to the PCX. However, in my experience, I have never been able to get a clear image with a fresnel--the quality is much better with the PCX lens. I believe that the image degradation IS because of using a non-point source light, and I think that a fresnel is much better suited or that type of light. There are rays of all different angles striking the fresnel at different points, and this makes the image very washed out. Why are these washing out effects reduced when using the PCX lens? I don't know, but keep in mind that the image quality is NOT perfect.
I also was not successful using a fresnel or PCX to "gather" the image to send it to a Fujinon or Delta lens assembly. I might just be setting it up wrong, but no dice. 😕
CanadianMike,
You are correct in your thinking, but if you are considering removing the back from a computer LCD panel, make sure that all of the driver boards can be moved from the active area. That has been the Achilles heel so far with that approach. In the last month, there have been lots of posts dealing with it, and I believe there has been some success with certain models.
If you wanted to go the easy route, panels made for overhead projectors can be placed on the OHP witout any modification. The quality might not be as high as using an LCD computer panel, but the prices are reasonable. Do a search on Ebay for "projection panel" to get an idea of what is out there.
-f4
f4,
A few pages back, Gunawan mentioned that he used the delta lens (turned backwards?) to gather the image, then projected it with the plano-convex. Is it realistic to be able to confirm this with your fuji? You might try that and see if you have better luck. As of this very moment I think this is the route i would like to go, as size and resolution are the major factors in my solution. Until the "gathering" idea was presented I was pretty torn on what to do, but now my choice seems clear (assuming we are able to get a prototype with as much success as Myren's first OHP setup).
Also (and I'm certain you have already thought of this, and i am just blathering on), might not want to give up on the fresnel completely and give it another shot whenever you might have a different lightsource handy.
Also, which LCD and what size are you using? After reading 87 pages in such a short time, everything is sort of blurred together.
I think maybe if I could get ahold of a 12" screen, that would probably be ideal (assuming it will allow me to take it apart).
Have any of you guys seen 800x600 or 1024x768 screens smaller than 14"?
Thanks guys -
A few pages back, Gunawan mentioned that he used the delta lens (turned backwards?) to gather the image, then projected it with the plano-convex. Is it realistic to be able to confirm this with your fuji? You might try that and see if you have better luck. As of this very moment I think this is the route i would like to go, as size and resolution are the major factors in my solution. Until the "gathering" idea was presented I was pretty torn on what to do, but now my choice seems clear (assuming we are able to get a prototype with as much success as Myren's first OHP setup).
Also (and I'm certain you have already thought of this, and i am just blathering on), might not want to give up on the fresnel completely and give it another shot whenever you might have a different lightsource handy.
Also, which LCD and what size are you using? After reading 87 pages in such a short time, everything is sort of blurred together.
I think maybe if I could get ahold of a 12" screen, that would probably be ideal (assuming it will allow me to take it apart).
Have any of you guys seen 800x600 or 1024x768 screens smaller than 14"?
Thanks guys -
jvisaria,
For simplicity, if you plan on using a point-source light, I would recommend just disassembling an OHP and constructing a custom enclosure using the optics. You could use a metal halide as a light source, for example, then the OHP fresnel, the LCD, and then the projection lens. This might not be the most compact setup, but it would at least be predictable. Before it is all over with, I might try that approach myself.
I am using an nView Spectra C panel, 640x480, that has about 9" of diagonal. I described it in more detail on the "Good panel/bad panel" thread in the Video section of this board.
Good luck!
-f4
For simplicity, if you plan on using a point-source light, I would recommend just disassembling an OHP and constructing a custom enclosure using the optics. You could use a metal halide as a light source, for example, then the OHP fresnel, the LCD, and then the projection lens. This might not be the most compact setup, but it would at least be predictable. Before it is all over with, I might try that approach myself.
I am using an nView Spectra C panel, 640x480, that has about 9" of diagonal. I described it in more detail on the "Good panel/bad panel" thread in the Video section of this board.
Good luck!
-f4
f4,
You're probably right about that -- considering my idea is pretty much exactly that, barring a few slight modifications (which may or may not work considering I am not too sure what I am doing).
We'll see how it goes -- still like the fuji/delta lense ideas, and at 10-20$ it wont break the bank to experiment.
Everyone,
Anyone know how much if a problem there would be with IR with a metal halide solution? I have done some quick web searching, but cant seem to find too much on it. Cooling the bulb itself is more intuitive to me -- but i am not sure how much the IR is going to affect the LCD? Woulld ventilating the area near the LCD be enough to cover it?
I wish this project was more electronic -- then I might actually be able to provide some support instead of just asking silly questions -- but I supposed thats how we learn.
Keep it up -
Jay
You're probably right about that -- considering my idea is pretty much exactly that, barring a few slight modifications (which may or may not work considering I am not too sure what I am doing).
We'll see how it goes -- still like the fuji/delta lense ideas, and at 10-20$ it wont break the bank to experiment.
Everyone,
Anyone know how much if a problem there would be with IR with a metal halide solution? I have done some quick web searching, but cant seem to find too much on it. Cooling the bulb itself is more intuitive to me -- but i am not sure how much the IR is going to affect the LCD? Woulld ventilating the area near the LCD be enough to cover it?
I wish this project was more electronic -- then I might actually be able to provide some support instead of just asking silly questions -- but I supposed thats how we learn.
Keep it up -
Jay
panel
update time..
well, i finally stopped "gonna wanna shoulda" ing and bought a ovation 820c for US$66 off ebay...the only problem is, i think it's about twice that price just to ship it over her to Australia 🙁 our local airline (ansett) went bust a while back, and they're having an auction of all their office stuff inc ohp's and projector screens, so hopefully things might start to happen soon if they go 4 the right price....i have access to a good digital camera too, so i WILL put up some pics, and lastly if anyone wants some pics hosted email me
seeya
update time..
well, i finally stopped "gonna wanna shoulda" ing and bought a ovation 820c for US$66 off ebay...the only problem is, i think it's about twice that price just to ship it over her to Australia 🙁 our local airline (ansett) went bust a while back, and they're having an auction of all their office stuff inc ohp's and projector screens, so hopefully things might start to happen soon if they go 4 the right price....i have access to a good digital camera too, so i WILL put up some pics, and lastly if anyone wants some pics hosted email me
seeya
LCD reduction
Well I had a thought if a fuji/delta projection lens can make a small image large cant it make a large image smaller if it was backwards?
Well I had a thought if a fuji/delta projection lens can make a small image large cant it make a large image smaller if it was backwards?
An externally hosted image should be here but it was not working when we last tested it.
Cables for LCD panel elements
Found this web site for a company that makes interface cables for LCD panel, by panel number. Maybe this is the ticket for converting panel monitors -
http://www.quadrangleproducts.com/index.cfm
Found this web site for a company that makes interface cables for LCD panel, by panel number. Maybe this is the ticket for converting panel monitors -
http://www.quadrangleproducts.com/index.cfm
So, as I understand, I could remove the back of a regular lcd panel and stick it on an OHP, or I could buy one of those projector panels designed for it? I'm basically trying to get something better than that old 100 inch tv deal with the crt with a fresnal in front. I understand the route I would be taking with the lcd would limit my quality, but would this setup be decent? I want to be able to properly watch it (unlike the 100 inch tv setup)fender4 said:
CanadianMike
Hi Everyone
Here are some pictures of my setup. I have a proxima 810 on top of a 5000 lumen overhead projector. Its being projected on a pinky white wall. Its connected to my PC which has a DVD drive and TV card. Playing nintendo 64 is class on this setup. I think you can see that the image is very good and I'm sure is 1000 times better than a 100ich TV thingy. I recommend this setup as a cheap way to get massive screen projection. I usually watch in the dark as this gives the best image but its still decent with some background light.
http://www.justexportcontrols.co.uk/andrew/projector.htm
Andy
Here are some pictures of my setup. I have a proxima 810 on top of a 5000 lumen overhead projector. Its being projected on a pinky white wall. Its connected to my PC which has a DVD drive and TV card. Playing nintendo 64 is class on this setup. I think you can see that the image is very good and I'm sure is 1000 times better than a 100ich TV thingy. I recommend this setup as a cheap way to get massive screen projection. I usually watch in the dark as this gives the best image but its still decent with some background light.
http://www.justexportcontrols.co.uk/andrew/projector.htm
Andy
Thumbs up to all
Hi, I'm a newbie, but have read all the threads posted so far and think that you all are doing a brillant job on all your projects.
The thread that axel666 posted on page 87 has a link to a page about bouncing light of the screen instead of through it as in figure 3 on that page, has anyone done this yet but with just a lcd screen?
I'm currently constructing my projector as I'm writing, I'm using a sony 5" in car lcd screen sorry don't have part numbers this one has direct video input but is abit harder to pull the screen apart have had a few mishaps already but have fixed them I have no manuals for either of these screens so makes it very hard to trace inputs etc. I also have a sony 5" in car navigation system. This one has seperate lcd screen and looks easy to pull apart so far, it does'nt have direct rca inputs so I've got to talk to an electrian about how to hook up a input into it.
I'm rammbling abit, but some of you were having trouble with your light source, I had a thought about that and when I come to that I'm going to surround the light source in a pramid shape using mirror's and at the pointed end use a convex lens to focus the light through and then througha bit of special glass and then through the lcd screen and out through a concaved lens, don't know what type of lens yet?
If I'm totally on the wrong road don't hesiate to tell me, At the moment I'm just experimenting and stumbling a long the way
Keep up the good work everyone
Cheers Jason
Hi, I'm a newbie, but have read all the threads posted so far and think that you all are doing a brillant job on all your projects.
The thread that axel666 posted on page 87 has a link to a page about bouncing light of the screen instead of through it as in figure 3 on that page, has anyone done this yet but with just a lcd screen?
I'm currently constructing my projector as I'm writing, I'm using a sony 5" in car lcd screen sorry don't have part numbers this one has direct video input but is abit harder to pull the screen apart have had a few mishaps already but have fixed them I have no manuals for either of these screens so makes it very hard to trace inputs etc. I also have a sony 5" in car navigation system. This one has seperate lcd screen and looks easy to pull apart so far, it does'nt have direct rca inputs so I've got to talk to an electrian about how to hook up a input into it.
I'm rammbling abit, but some of you were having trouble with your light source, I had a thought about that and when I come to that I'm going to surround the light source in a pramid shape using mirror's and at the pointed end use a convex lens to focus the light through and then througha bit of special glass and then through the lcd screen and out through a concaved lens, don't know what type of lens yet?
If I'm totally on the wrong road don't hesiate to tell me, At the moment I'm just experimenting and stumbling a long the way
Keep up the good work everyone
Cheers Jason
update 2
well, the auction was fun - ALOT of people buying things almost exactly what they are worth new....like f*#ked cordless drills for $80 (bout US$38)...but more importantly i got the projector screen (woohoo) for $100 aust. it is only about 6 months old, and goes to a maximum of 88 inches diagonal...it's amazing how much a proper screen enhances the picture, i used it on my 100inch tv thingy and it automatically almost doubled the brightness compared to my cream wall! now i have to wait for my ovation 820c panel to come from america now (grrrr) wish me luck 🙂
BTW great pictures Andy! using the ovation 810 what was the refresh rate like on faster scenes?
well, the auction was fun - ALOT of people buying things almost exactly what they are worth new....like f*#ked cordless drills for $80 (bout US$38)...but more importantly i got the projector screen (woohoo) for $100 aust. it is only about 6 months old, and goes to a maximum of 88 inches diagonal...it's amazing how much a proper screen enhances the picture, i used it on my 100inch tv thingy and it automatically almost doubled the brightness compared to my cream wall! now i have to wait for my ovation 820c panel to come from america now (grrrr) wish me luck 🙂
BTW great pictures Andy! using the ovation 810 what was the refresh rate like on faster scenes?
I think we're on the right way with the pcx lens i have seen a page where they sold mitshubishi pcx fresnel (yup thats what they called um) lenses that where used in projection tvs, it would be nice tough if we could get our hands on a drawing of how they where placed in such a setup =)
But i'm posting regarding this:
8.4" Screen Size
– 800 x 600 Dots Resolution
– 150 cd/m² Brightness
– 200:1 Contrast Ratio
– 0...60 °C Operating Temperature
– Accessories: Control Board: UPLVDS
Inverter: OP90118
Cable
– also a version with included Touchpanel available:
UB084S01-2
UP084S01 ( UP02001)
5 pcs. on stock for unit price 329,90 *
25 pcs. and higher quantities : standard delivery time 10 weeks ; for unit price 243,00 *
Delivery conditions : ex works
Payment conditions : payment in advance
Offer conditions : without engagement; subject to prior sale
I don't know if anyone had been able to find something better and its a big smack of money for a diy projector but if enough ppl are intrested perhaps we could get up to 25 of um then the price wouldn't b so bad =)
Anyway i got it from this page:
http://www.data-modul.de/de/produkte/nonedit/produktinfo.html?kategorie=A&id=35
If anyone finds something better plze let me know =)
ps
no luck on the quarter waves plates yet, but i've seen sum prices of similar products and they're kinda out of our league $400 orso.
But i'm posting regarding this:
8.4" Screen Size
– 800 x 600 Dots Resolution
– 150 cd/m² Brightness
– 200:1 Contrast Ratio
– 0...60 °C Operating Temperature
– Accessories: Control Board: UPLVDS
Inverter: OP90118
Cable
– also a version with included Touchpanel available:
UB084S01-2
UP084S01 ( UP02001)
5 pcs. on stock for unit price 329,90 *
25 pcs. and higher quantities : standard delivery time 10 weeks ; for unit price 243,00 *
Delivery conditions : ex works
Payment conditions : payment in advance
Offer conditions : without engagement; subject to prior sale
I don't know if anyone had been able to find something better and its a big smack of money for a diy projector but if enough ppl are intrested perhaps we could get up to 25 of um then the price wouldn't b so bad =)
Anyway i got it from this page:
http://www.data-modul.de/de/produkte/nonedit/produktinfo.html?kategorie=A&id=35
If anyone finds something better plze let me know =)
ps
no luck on the quarter waves plates yet, but i've seen sum prices of similar products and they're kinda out of our league $400 orso.
Re: Thumbs up to all
I don't really think this would give a good result with a normal lcd screen since the ones we're using aren't made to do that and you'd be losing a lot of light bouncing it off a mirror placed behind one. 🙂
greetz,
Axel
Jaro said:
I don't really think this would give a good result with a normal lcd screen since the ones we're using aren't made to do that and you'd be losing a lot of light bouncing it off a mirror placed behind one. 🙂
greetz,
Axel
rear project mirror
there is an auction for a set of mirrors for a rear projection tv at ebay
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1723106919
thought you guys 'd like to know
there is an auction for a set of mirrors for a rear projection tv at ebay
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1723106919
thought you guys 'd like to know
bouncing light
Hi Axel
The picture that I'm refering to bounces the light from the front of the panel which is set to 45 degress, I would say that you would have to remove the front glass maybe but have'nt tried that yet, then you use a mirror at 45 degress to the lcd screen, which beams into the projector lens. I would say the the lens choice would be critical to get a good result. It's alot like looking into a window reflecting the surroundings if you are in the right place it is very clear.
Just another option maybe🙂
what does anyone think about enclosing the light source in a primaid shape of mirrors and concentrating it through a convexed lens at the pointed end, would this work better than using a reflective surface just at the back of the light?
Cheers
Jason😀
Hi Axel
The picture that I'm refering to bounces the light from the front of the panel which is set to 45 degress, I would say that you would have to remove the front glass maybe but have'nt tried that yet, then you use a mirror at 45 degress to the lcd screen, which beams into the projector lens. I would say the the lens choice would be critical to get a good result. It's alot like looking into a window reflecting the surroundings if you are in the right place it is very clear.
Just another option maybe🙂
what does anyone think about enclosing the light source in a primaid shape of mirrors and concentrating it through a convexed lens at the pointed end, would this work better than using a reflective surface just at the back of the light?
Cheers
Jason😀
Hey, im new to this LCD projector thing, but I am going all the way. I have ordered my LCD Projection Panel (its a Sharp QA-1150) and I've ordered my Lens. The lens i ordered is this one (the delta 20 tv projection lens from surplus shed):
http://www.surplusshed.com/list.cfm?ID=L1813&Category=Lenses
It is "Designed specifically for a compact rear projection TV." It has a focal length of 90mm, f/1.0. I dont understand exactly how focal length works, so my que_stion to you guys iis roughly how far from my wall will this lens have to be to produce about a 6X8 foot image? Also, does it matter a lot if the Projector isnt perfectly square with the wall? I want to mount it on the ceiling, so it will have to be slanted downwards a bit to centre the image.
Thanks for any help!
An externally hosted image should be here but it was not working when we last tested it.
http://www.surplusshed.com/list.cfm?ID=L1813&Category=Lenses
It is "Designed specifically for a compact rear projection TV." It has a focal length of 90mm, f/1.0. I dont understand exactly how focal length works, so my que_stion to you guys iis roughly how far from my wall will this lens have to be to produce about a 6X8 foot image? Also, does it matter a lot if the Projector isnt perfectly square with the wall? I want to mount it on the ceiling, so it will have to be slanted downwards a bit to centre the image.
Thanks for any help!
cool site
If you want to see what different kinds of lenses do to light, heres a cool site:
Here
If you want to see what different kinds of lenses do to light, heres a cool site:
Here
An externally hosted image should be here but it was not working when we last tested it.
Report: VP140 NOT recommended for DIY, OHP
Well, the gal here at work finished the extension of the small cable and that seemed to work fine, at least physically.
However, somewhere along the way, the other flex print cable going to the square circuit board that connects to a driver board
started to crack along the edge of the PCB, taking out about 8 connections.
We're going to try to save the panel, but it looks doubtful, nearly impossible. I'll probably be out $150. Glad it wasnt $350 or more!
I guess she feels sorry for when asked what I was going to do, I indicated "probably throw it in the trash"
Even if successful, I'll DEFINITELY just put it back together and just use it for a monitor. There's NO WAY that larger flex cable can take any stress or strain likely encountered in trying to get this atop the OHP - even for just a look. Not if it cracked over just a few flexures like this!
My conclusion is that even with professional help, dealing with the problem of getting the driver boards out of the way can be a
"if the thunder dont get ya then the lightning will" situation. I was
really suprised to see that crack there...tanked my whole project.
Conclusion? You may get a VP140 to work in this way if you're lucky and careful. After this experience, I'm going to abandon the possibility - the little cables and flex-print connectors are just too fragile to be manipulated AT ALL. They were designed to be flexed only a few times, apparently. The panel itself was designed with no regard to being able to move the driver boards -and why would it be?
Too bad 😡 I'd only reccommend buying a panel intended for OHP use, where the LCD element is actually designed to be cabled such that no driver boards are located directly behind the glass. Even though the light gain due to aperature size increase for the panel monitors is tempting.
Well, it's the next person's turn "up to bat" - maybe we'll find another model 1024X768 16.7M color panel monitor where this can be reasonably done - without disasterous consequences - yet!
Well, the gal here at work finished the extension of the small cable and that seemed to work fine, at least physically.
However, somewhere along the way, the other flex print cable going to the square circuit board that connects to a driver board
started to crack along the edge of the PCB, taking out about 8 connections.
We're going to try to save the panel, but it looks doubtful, nearly impossible. I'll probably be out $150. Glad it wasnt $350 or more!
I guess she feels sorry for when asked what I was going to do, I indicated "probably throw it in the trash"
Even if successful, I'll DEFINITELY just put it back together and just use it for a monitor. There's NO WAY that larger flex cable can take any stress or strain likely encountered in trying to get this atop the OHP - even for just a look. Not if it cracked over just a few flexures like this!
My conclusion is that even with professional help, dealing with the problem of getting the driver boards out of the way can be a
"if the thunder dont get ya then the lightning will" situation. I was
really suprised to see that crack there...tanked my whole project.
Conclusion? You may get a VP140 to work in this way if you're lucky and careful. After this experience, I'm going to abandon the possibility - the little cables and flex-print connectors are just too fragile to be manipulated AT ALL. They were designed to be flexed only a few times, apparently. The panel itself was designed with no regard to being able to move the driver boards -and why would it be?
Too bad 😡 I'd only reccommend buying a panel intended for OHP use, where the LCD element is actually designed to be cabled such that no driver boards are located directly behind the glass. Even though the light gain due to aperature size increase for the panel monitors is tempting.
Well, it's the next person's turn "up to bat" - maybe we'll find another model 1024X768 16.7M color panel monitor where this can be reasonably done - without disasterous consequences - yet!
Sorry to hear it, jjasniew
That's rough, man. Lately I've been thinking the same thing with regard to panels. It's a big gamble to just try some panel and hope it works. I'm having trouble finding a suitable one, though. It's too bad all the companies making LCD projection panels started making stand-alone projectors. If I could get a panel with the specs of the viewsonic vg150 that went on an overhead, I'd buy it in a second. Oh well, I guess I'll keep looking.
Axeman
That's rough, man. Lately I've been thinking the same thing with regard to panels. It's a big gamble to just try some panel and hope it works. I'm having trouble finding a suitable one, though. It's too bad all the companies making LCD projection panels started making stand-alone projectors. If I could get a panel with the specs of the viewsonic vg150 that went on an overhead, I'd buy it in a second. Oh well, I guess I'll keep looking.
Axeman
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