DIY Video Projector

[xblocker]

ZeCo

Originally posted by ZeCo

the MLA will distribute the light more even and therefore it will be a lot more bright. With a polarizer right after the MLA, the ray will be parallel before reach the LCD.

[/B]

ZeCo,
Can you point me to any source, where polarizers are claimed to make divergent beams parallel?

xblocker

[tech head]

Those MLAs are just a bunch of lenses etched on a transparent medium. Why not see if we can find a MLA that is etched on a polarizer?

Two birds with one stone!

[Gunawan W]

I have an idea about cooling system.
It's using water for heat transfer.
See in my webpages below:
water cooler

[ZeCo]

Originally posted by xblocker
ZeCo



ZeCo,
Can you point me to any source, where polarizers are claimed to make divergent beams parallel?

xblocker

they wont, but they would reflect the unparallel ones and the quarter wave retarder and mirror would recycle it. dunno if i explained well, but with the mirror/polarizer/wave retarder, you could have much more efficiency.

I need to organize my links, here is one of them.

from http://www.research.ibm.com/journal/rd/423/tanase.html

• Recycling the parallel polarization
P-polarization transmitted out of the light pipe is converted into S-polarization by a polarization converter placed at the end opposite to the input face. The polarization converter consists of a quarter-wave retarder and a reflector. The axis of the quarter-wave retarder is either parallel or perpendicular to the illuminating face. Light entering this unit passes through the quarter-wave retarder twice, as shown in Figure 2. Therefore, linearly polarized light whose plane of polarization is either parallel or perpendicular to the illuminating face has its plane of polarization rotated by 90%° by this polarization converter. In our design, P-polarization transmitted out of the light pipe is converted into S-polarization by this unit and turned back into the light pipe to be recycled.

The recycling efficiency of the polarization converter is determined by the efficiency of the quarter-wave retarder and the transmittance of light at the end face of the light pipe. The typical wide-bandwidth quarter-wave retarder available at present has an efficiency of approximately 75%. The transmittance at the end face of a light pipe is 96%. Therefore, the efficiency of the polarizer converter is calculated to be 69%.

[tomithy83]

gunawan i've been planing to dop this very sae thing with a halogen bulb thanks for solidifing the idea (in my head)

[jamie]

for you newbies theres some good info on page 119

[prjctr_builder]

Originally posted by Gunawan W
I have an idea about cooling system.
It's using water for heat transfer.
See in my webpages below:
water cooler

this is the exact same idea i had, but it failed in the end because the whole design has to be huge to work, plus it is hella loud. i think that you should rethink your idea a little. Especially because i came up with it first...hehe


aleksey

[dwalls32]

Actually, it shouldn't have to be that big to work. Think pc size water cooling systems. Besides, space beats noise.

[BennySP]

Hey sorry to do this, but 134 pages is too much to catch up on. Just wanna get some help before I order the parts for a summer project.

Basic Plan
1) I want to keep if relatively small, no big OHP. So, I plan to use the 5" Thin LCD module from partsexpress.com, #205-013, 960x234 pixels

2) I would like to use a cluser of LED's, probably around 30, but I can go higher. I'd like to keep this relatively cheap. How do I arrange these? Can someone please post a picture of how the cluster should be setup, (I could use less or more white LED's, just suggest). Also, how are they kept in place? set up? pictures woudl be really helpful

3) I'd like to keep this striaght, as in leds to lcd, no mirrors in between, just for simplicity, first video projection project.

4) What lenses will I need, I am guessing a condensor for hte leds, and a projection lens. Any specific lens suggestions would be helpful (as in exact part).

5) What power supply will I need for say the LCD and up to 50 of the white LED's.

I think I have covered everything, if I missed something, go ahead and suggest it. Thanks in advance.

[xblocker]

BennySP,
It may be anyhow cheaper to use the search function in this thread, look for 'led", before you kick off your money! There isn't a full working version of a LED-light based projector!
Just an advice...

xblocker

P.S. At the bottom of the side click 'show printable version'. All posts on one site.