Here is a design for a inexpensive and relatively easy to build light recycler. It only lets out S polarized light and uses a small 3" reflector and HMI bulb.
I don't know if it would improve typical OHP setup that need light at exact location. It is more meant for use with a long columator that negates need for the first fresnel lens.
All areas inside are highly reflective material except for the front beam splitters. The rose colored beam splitter passes S polarized light and reflects P polarized light into the internal mirror which then reflects the P polarized light through the P pass beam splitter ( blue or purple color). The P polarized light then goes through a 1/4 wave retarder (yellow) to turn it into S polarization and any S polarization light that hits the P beam splitter will get bounced back inside the reflective housing.
Any S polarized light that hits the P beam splitter will be bounced back inside the housing and reflected around until it finds a path through the S beam splitter.
Thus all light should eventually get out and when it leaves the housing it is all S polarized.
Hezz
I don't know if it would improve typical OHP setup that need light at exact location. It is more meant for use with a long columator that negates need for the first fresnel lens.
All areas inside are highly reflective material except for the front beam splitters. The rose colored beam splitter passes S polarized light and reflects P polarized light into the internal mirror which then reflects the P polarized light through the P pass beam splitter ( blue or purple color). The P polarized light then goes through a 1/4 wave retarder (yellow) to turn it into S polarization and any S polarization light that hits the P beam splitter will get bounced back inside the reflective housing.
Any S polarized light that hits the P beam splitter will be bounced back inside the housing and reflected around until it finds a path through the S beam splitter.
Thus all light should eventually get out and when it leaves the housing it is all S polarized.
Hezz
Attachments
hezz
i'm interested to buy a xenarc 700 v (225 $ only )7"
did you buy one?
did you dismantle it?
bye
i'm interested to buy a xenarc 700 v (225 $ only )7"
did you buy one?
did you dismantle it?
bye
moi
moi the xenarc is a great little lcd id go the vga one personally but the tv one u want to get is good enough for dvd and vids ect, these screens have great reso the best that ive seen in a small screen readily availible today but however u will need to lengthen 1 cable along is a pic of whats in the back
Trev
this pic is of an opened vga version but will be the same as a tv version
moi the xenarc is a great little lcd id go the vga one personally but the tv one u want to get is good enough for dvd and vids ect, these screens have great reso the best that ive seen in a small screen readily availible today but however u will need to lengthen 1 cable along is a pic of whats in the back
Trev
this pic is of an opened vga version but will be the same as a tv version
Attachments
😉 many thanx for your reply
please tell me what cable and how many contacts do i need to solder
i think i'll use a 7" fresnel
soon i'll post a pic of my project( i focused on the heat of the light)
i hope you'll correct me if i'm wrong
i really want to thank you ace-3000 because you answer most of us
bye
sorry my english is not the best
bye
please tell me what cable and how many contacts do i need to solder
i think i'll use a 7" fresnel
soon i'll post a pic of my project( i focused on the heat of the light)
i hope you'll correct me if i'm wrong
i really want to thank you ace-3000 because you answer most of us
bye
sorry my english is not the best
bye
moi
no probs moi the cable u need to lengthen is to the top left im not sure how manny contacts but it looks to me about 9 or 10 i havnt done one of these myself so i cant ell u the rest lol
Trev
no probs moi the cable u need to lengthen is to the top left im not sure how manny contacts but it looks to me about 9 or 10 i havnt done one of these myself so i cant ell u the rest lol
Trev
7 inch screen
MOI,
It has been weeks since I looked at this thread. I thought that it had died out. I have not continued to persue the 7 inch LCD projector because I am planning on building one with a 14 or 15 inch LCD screen. There are a couple of reasons for this. One, I want somewhat higher resolution for a 80 -120 inch diagnol screen. Second, because standard computer grade LCD screens are so inefficient at transmitting light, I want a larger LCD screen so that I can get more total light projected on the wall. It was been estimated that a high resolution TFT LCD is only about 10% efficient at allowing the light entering it to pass. Therefore for each additional square inch of LCD screen I can put more total light into the system.
Hezz
MOI,
It has been weeks since I looked at this thread. I thought that it had died out. I have not continued to persue the 7 inch LCD projector because I am planning on building one with a 14 or 15 inch LCD screen. There are a couple of reasons for this. One, I want somewhat higher resolution for a 80 -120 inch diagnol screen. Second, because standard computer grade LCD screens are so inefficient at transmitting light, I want a larger LCD screen so that I can get more total light projected on the wall. It was been estimated that a high resolution TFT LCD is only about 10% efficient at allowing the light entering it to pass. Therefore for each additional square inch of LCD screen I can put more total light into the system.
Hezz
thanx fo your replies
ace-3000
is it esy to access the lcd itself?
hezz
i understand what you mean
i'm not looking for a huge screen
bye
ace-3000
is it esy to access the lcd itself?
hezz
i understand what you mean
i'm not looking for a huge screen
bye
moi/hez
moi im not sure bud, do u mean taking the thing apart like the screws of the back panel? have a look at this link, if a women can do it so can u lol it must be fairly easy
http://www.talix.com/
Hez how do u figure u can fit more light in a bigger lcd than a smaller one? its more like u need more light per square inch than less cos dont forget the wider u make the beam on a point sorce the more light u loose in the way of the beam being so wide, its lress intense and the beams are less strait
Trev
moi im not sure bud, do u mean taking the thing apart like the screws of the back panel? have a look at this link, if a women can do it so can u lol it must be fairly easy
http://www.talix.com/
Hez how do u figure u can fit more light in a bigger lcd than a smaller one? its more like u need more light per square inch than less cos dont forget the wider u make the beam on a point sorce the more light u loose in the way of the beam being so wide, its lress intense and the beams are less strait
Trev
trev
no i meant get the lcd alone (nude ?!) to put it behind a fresnel lens
or another lens
a friend of mine is optician i'll meet him next week and ask him what lenses he can get
bye
no i meant get the lcd alone (nude ?!) to put it behind a fresnel lens
or another lens
a friend of mine is optician i'll meet him next week and ask him what lenses he can get
bye
moi
hehehe get me some too lol with that lcd u should keep some of the outer framing to use as a mounting for it instead of wedging it between somthing, its what i did with mine anyway, when u get upto that bit give us a shout and ill tell ya what to keep
Trev
hehehe get me some too lol with that lcd u should keep some of the outer framing to use as a mounting for it instead of wedging it between somthing, its what i did with mine anyway, when u get upto that bit give us a shout and ill tell ya what to keep
Trev
trev
ok
what lense can be the best fresnel or...
do you think computer monitor's filters can do a good job for filtering uv ir..
bye
ok
what lense can be the best fresnel or...
do you think computer monitor's filters can do a good job for filtering uv ir..
bye
Ace 3000
My theory on the larger LCD is that a high resolution LCD will only let about 10 -20 % of the light to pass through. That being the case if the viewing screen is of a fixed size and the light source is of a fixed size then the more square inches the LCD panel is the more total lumens you should be able to get onto the screen. I think that is why the guys using the 14-15 inch panels are getting the best pictures. Some of the pictures from the OHP LCD panels with a smaller LCD size look OK but don't have the color saturation.
Hezz
My theory on the larger LCD is that a high resolution LCD will only let about 10 -20 % of the light to pass through. That being the case if the viewing screen is of a fixed size and the light source is of a fixed size then the more square inches the LCD panel is the more total lumens you should be able to get onto the screen. I think that is why the guys using the 14-15 inch panels are getting the best pictures. Some of the pictures from the OHP LCD panels with a smaller LCD size look OK but don't have the color saturation.
Hezz
Hezz,
Is this project still on? Have you finished it yet? I just stumbled upon it today and wondered what the status of this project was. Did you go this route, r have you changed to a different plan?
Thanks a lot. Nice models BTW. I have completely esigned my PJ in autocad. I get to begin building next weekend. Can't wait.
Take care.
Is this project still on? Have you finished it yet? I just stumbled upon it today and wondered what the status of this project was. Did you go this route, r have you changed to a different plan?
Thanks a lot. Nice models BTW. I have completely esigned my PJ in autocad. I get to begin building next weekend. Can't wait.
Take care.
Mccamp82,
I did not build this project because I found out that I had a lot of optical misconceptions at the time I designed it. With some modifications and changes it could be made to work. The box and mounting assembly I think is a good way to mount a small LCD. It would work well with the Lilliput 7 inch 800 x 480 that Ace has used.
If you want to approach a small projector with a box design similar to this let me make the following suggestions.
1) Use the fujinon copier lens from surplus shed. I thinks it's about 11 USD.
2) For the small LCD the field lens in front of the LCD between the LCD and the objective lens can be disgarded and a double fresnel placed behind the lcd. I would use a light engine similar to the one that Ace is using. I did this design back in the days when everyone was using those big globe commercial metal halide lights but it turns out that this light engine dosn't work well at all with a large bulb.
3) The light recycling prisms are state of the art but difficult to build. And they need parallel columated light to work well. If they are use the field lens needs to be used.
4) I will see if I can find the old solid model files and modify them some.
Hezz
I did not build this project because I found out that I had a lot of optical misconceptions at the time I designed it. With some modifications and changes it could be made to work. The box and mounting assembly I think is a good way to mount a small LCD. It would work well with the Lilliput 7 inch 800 x 480 that Ace has used.
If you want to approach a small projector with a box design similar to this let me make the following suggestions.
1) Use the fujinon copier lens from surplus shed. I thinks it's about 11 USD.
2) For the small LCD the field lens in front of the LCD between the LCD and the objective lens can be disgarded and a double fresnel placed behind the lcd. I would use a light engine similar to the one that Ace is using. I did this design back in the days when everyone was using those big globe commercial metal halide lights but it turns out that this light engine dosn't work well at all with a large bulb.
3) The light recycling prisms are state of the art but difficult to build. And they need parallel columated light to work well. If they are use the field lens needs to be used.
4) I will see if I can find the old solid model files and modify them some.
Hezz
Imo you did a good job on this project at the time too hezz, ive prety much got the right angle calculations to get the light reflectiong from the pyramid paralelle too. Sorry for the formula for the light too, my mrs has to go through a book thats about 6inches thick to get it and its not here at our house.
Trev
Trev
Ace,
Thanks for the Kudos and the information. When I originally had that projector design I only had that big Fuji CRT projection lens and it needed an image about half an inch away to work. One thing for certain though is that lens is very good quality and passes a lot of light. I didn't realize that a simpler solution like the copier lens would work. I guess this design could still be made to work if the field lens and the other lens were made right. The elliptical reflector would require a small bulb though and send the light out into the trapazoid from the second focal point of the reflector.
Hezz
Thanks for the Kudos and the information. When I originally had that projector design I only had that big Fuji CRT projection lens and it needed an image about half an inch away to work. One thing for certain though is that lens is very good quality and passes a lot of light. I didn't realize that a simpler solution like the copier lens would work. I guess this design could still be made to work if the field lens and the other lens were made right. The elliptical reflector would require a small bulb though and send the light out into the trapazoid from the second focal point of the reflector.
Hezz
I agree hezz, even the arc of the bulb im using in the spherical is too big, its 9mm but idealy we only want a 1mm arc to get the most acurate result as possible, until we get a lamp thats got this size arc we wont have the most acurate results. For the pyramid 45deg seams to work best, and ill tell ya what it does make a big diff when we recycle light.
The copy lens wasnt around at the time of your idea so yeah we wer realy left either with a diylabs triplet or this fujinon rear projection lens, i think with a modd we could lengthen the focal on that lens and make it usable, more of your area then mine to cover imo lol.
Btw did you see the link i posted in the other thread regarding an imaging system for a scope? some nice 3d pictures in there with comparison data.
Trev
The copy lens wasnt around at the time of your idea so yeah we wer realy left either with a diylabs triplet or this fujinon rear projection lens, i think with a modd we could lengthen the focal on that lens and make it usable, more of your area then mine to cover imo lol.
Btw did you see the link i posted in the other thread regarding an imaging system for a scope? some nice 3d pictures in there with comparison data.
Trev
Ace,
Ya, I saw those pictures. Kind of amazing but I was a little confused as to what the designs were for. They reminded me of this moveable lens system they have for the movie industry called of all things a superscope. But not the old variable anamorphic lens. It's like a snaking scope that can move around in different directions.
Hezz
Ya, I saw those pictures. Kind of amazing but I was a little confused as to what the designs were for. They reminded me of this moveable lens system they have for the movie industry called of all things a superscope. But not the old variable anamorphic lens. It's like a snaking scope that can move around in different directions.
Hezz
Hezz
I think its for a ccd telescope, its got some nice info in it though, looks like they use the same program you use. I wouldnt mind that program, is there a place where i can this from?
Thanks in advance
Trev
btw i think you should keep this thread going, you are certainly talented hezz in this feild and full of ideas.
I think its for a ccd telescope, its got some nice info in it though, looks like they use the same program you use. I wouldnt mind that program, is there a place where i can this from?
Thanks in advance
Trev
btw i think you should keep this thread going, you are certainly talented hezz in this feild and full of ideas.
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