hey everybody!
OK...heres the deal....
I have looked all over this forum and i cant find anything about using a 15" Flat screen CRT computer monitor in a reflective system. I know this type of configuration exists....I started at around the age of 12 using the parts from an old projector and a standard 13" TV. needless to say...the results were poor...but it still impressed the hell out of my friends ..HAHA...anyways...now im a bit older and Ive been thinking that i might be able to produce a decent projection system by arranging the crt facing toward the ceiling....and using a system of leds to reflect even more light off of the screen. i would then use a polarization filter to decrease possible reflection of leds and glare, use a special mirror and set of lenses to collect the light and project the image. It would all be mounted into a custom coffee table. Would this not work? Also...does anyone know where i might be able to find more information about using multiple lenes in a projection system.....Im hoping that i could engineer some sort of mechanism that would allow me to reduce or enlarge the projected image as well as focus it....? THANX EVERYONE>>>IHOPE TO HEAR YOUR REPSONSES......🙂
OK...heres the deal....
I have looked all over this forum and i cant find anything about using a 15" Flat screen CRT computer monitor in a reflective system. I know this type of configuration exists....I started at around the age of 12 using the parts from an old projector and a standard 13" TV. needless to say...the results were poor...but it still impressed the hell out of my friends ..HAHA...anyways...now im a bit older and Ive been thinking that i might be able to produce a decent projection system by arranging the crt facing toward the ceiling....and using a system of leds to reflect even more light off of the screen. i would then use a polarization filter to decrease possible reflection of leds and glare, use a special mirror and set of lenses to collect the light and project the image. It would all be mounted into a custom coffee table. Would this not work? Also...does anyone know where i might be able to find more information about using multiple lenes in a projection system.....Im hoping that i could engineer some sort of mechanism that would allow me to reduce or enlarge the projected image as well as focus it....? THANX EVERYONE>>>IHOPE TO HEAR YOUR REPSONSES......🙂
will it work? your 12-year-old-project TV projector wasn't a reflective system. it used light emitted from the screen and focus it through the lens, if I understand it right.
now, take a light torch and shine on the screen, or take the TV/screeen out on a shining day. can you see the content on the screen now?
somebody tell me I am wrong please.
now, take a light torch and shine on the screen, or take the TV/screeen out on a shining day. can you see the content on the screen now?
somebody tell me I am wrong please.
Actually..i realize this...which is why i have included the polarization filter into the schematics.....
I also understand that a polarization filter would significantly reduce the amount of emmited light to be projected, however....using the white light emmiting leds so often discussed in this forum, im hoping to counterbalance its effect. I know its seems redicules..THats exactly the reason i brought it up! However....does anybody have any suggestions for brightening a high res CRT monitor...without critically reducing its life? THANX
I also understand that a polarization filter would significantly reduce the amount of emmited light to be projected, however....using the white light emmiting leds so often discussed in this forum, im hoping to counterbalance its effect. I know its seems redicules..THats exactly the reason i brought it up! However....does anybody have any suggestions for brightening a high res CRT monitor...without critically reducing its life? THANX
CrazyOnYou1302 said:
The major worry in trying to mod a crt tube is that it would critically reduce your life😉
Seriously, it is very dangerous to attempt to modify any CRT device without years of experience and the appropriate safety equipment. Even then, you would probably fail anyway, TVs are designed to a price point and manufacturers would not put surplus capacity into the tube and circuitry, it costs money
About the lenses
I've got a couple of EIKI OHP that use the "tripple lens" configuration, this allows you to move the head stock up and down to increase or decrease the image size, and also to focus the image. Since both went out (transformers?) I upgraded to an ELMO HP-305 Solar Deluxe, great OHP by the way, but the Focus ring is loose and every 5 min or so I had to re-focus(just taped it in place for now) plan on transplanting the head stock and arm from the EIKI (which I believe is better than the ELMO's) so I can have more flexability. Maybe you can order one of these heads from the company?
I've got a couple of EIKI OHP that use the "tripple lens" configuration, this allows you to move the head stock up and down to increase or decrease the image size, and also to focus the image. Since both went out (transformers?) I upgraded to an ELMO HP-305 Solar Deluxe, great OHP by the way, but the Focus ring is loose and every 5 min or so I had to re-focus(just taped it in place for now) plan on transplanting the head stock and arm from the EIKI (which I believe is better than the ELMO's) so I can have more flexability. Maybe you can order one of these heads from the company?
Xrays and burnt phosphers
CRT projectors have a few characteristics that help them work:
Flat faced tubes help them couple to liquid cooling devices on the face of the tube. The cooling extends the life of the phosphors.
Increasing the brightness on a front view CRT to the level you desire, would like require that the HV supply be jeeped up to the point where unsafe levels of x-ray radiation are produced. It would likely leave a shadow of your DNA on the screen if you ever walked in front of the beam. That’s if the TV doesn’t have a well designed X-ray protection circuit. Sony's will kick out if you get he HV one or two KV above speck.
A color TV can have anywhere from 15 to 35 KV of potential at the anode. I never tried measuring the current, but I know 1st hand how painful it can be and can tell a few antidotes about fatalities.
I think it might be more fun, and a whole lot safer, to look into trying combining CRT and LCD technology with a big fat light bulb like the Hughes JVC light amplifier does.
Having said this, I don’t know of anyone who has tried it. Sounds like might be good territory for a pioneering effort that wont (likely) alter your DNA.
CRT projectors have a few characteristics that help them work:
Flat faced tubes help them couple to liquid cooling devices on the face of the tube. The cooling extends the life of the phosphors.
Increasing the brightness on a front view CRT to the level you desire, would like require that the HV supply be jeeped up to the point where unsafe levels of x-ray radiation are produced. It would likely leave a shadow of your DNA on the screen if you ever walked in front of the beam. That’s if the TV doesn’t have a well designed X-ray protection circuit. Sony's will kick out if you get he HV one or two KV above speck.
A color TV can have anywhere from 15 to 35 KV of potential at the anode. I never tried measuring the current, but I know 1st hand how painful it can be and can tell a few antidotes about fatalities.
I think it might be more fun, and a whole lot safer, to look into trying combining CRT and LCD technology with a big fat light bulb like the Hughes JVC light amplifier does.
Having said this, I don’t know of anyone who has tried it. Sounds like might be good territory for a pioneering effort that wont (likely) alter your DNA.
How projector works
Transmittive projectors - CRT tube, LCD panel
Reflective projectors _
Microelectromechanical systems (MEMS)
Digital micromirror device (DMD, DLP)
Grating light valve (GLV)
Liquid crystal on silicon (LCOS)
There is no CRT reflective projectors (as far as I can find)
Transmittive projectors - CRT tube, LCD panel
Reflective projectors _
Microelectromechanical systems (MEMS)
Digital micromirror device (DMD, DLP)
Grating light valve (GLV)
Liquid crystal on silicon (LCOS)
There is no CRT reflective projectors (as far as I can find)
- Status
- Not open for further replies.