DIY Video Projector

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#84
Robin,

The Sales Manager of Fresnel-Optics Germany replied to my email, and he said that the company usually only sells to systems manufacturers (sure, how many optics amateurs are there????) and to sell a lens to me they have to know the exact specs.
But he gave some examples:
OHP lens costs E 31 without taxes, and a RPTV lens (US import) dimension 790 x 1040 mm costs E 560.

Regards
Timo
 
#86
Real Close...

I'm real close now to getting this all together. The image from the panel looks real nice. I took the panel apart; it would be easy to transfer the guts to my enclosure.

I found the panel accepts S-Video for connecting to a DVD player for better picture quality.

I'm going to use 2 fresnel lenses before the LCD and a 75mm plano-convex after. The latter was recommended to me by a tech at Edmund Optics. He was very helpful.

I only need the three lenses and I can start testing again.

Later

Vince
 
#87
Found Frensels

I found frensel lenses, also known as page magnifiers at office supply store. They had the 2 sizes I needed. One was the size a a page, 8.5"x11" the other 2"x3". Got both for about $10 US. I bought these at OfficeMax, but I saw the 8.5x11 on the Staples site for $7.49 also.

They have a magnification of about 2x. I'm placing the small frensel first, then the larger before the LCD.

Just one lense to go.

Vince
 
#89
That's a good question. One that I'd like a better answer to. There are high resolution color LCDs, but they are expensive as hell for just one.

Most LCD projectors use 3 monochrome LCDs. The light color is divided by dichrotic mirrors. They reflect R,B or green and pass all other light. These monochrome LCD are probably cheaper to make then color ones. Check out some of the previous replies for hi resolution color LCDs.

I got the last lense yesterday. It looks real good. I want to start putting it together this weekend, if time allows.

Vince
 
#90
might be of interest:

<a href="http://www.allelec.com/VGALCDMono.html">VGA LCD Screen with controller.....$89.00</a>
<i>Totally self contained, all power is supplied by the controller card. Great for projects, corners, limited space areas. Use these for NT, Novel servers. The metal frame around the LCD is removable. The there are no controls for the backlight, you will need to provide a momenty SPST switch. The DC inverter PCB is mounted on the rear of the display assembly.

<li>Cirrus Logic 16 Bit (ISA) 512K Controller Non-upgradable.
<li>640x480 Resolution
<li>VGA Compatible
<li>16 Gray scale
<li>Windows 3.1/9x
<li>Linux (XF86_SVGA) compatible
<li>Windows NT
<li>5 7/8 x 10 3/8
<li>9.6 in diagonal viewing area.</i>


Regards
James
 
#91
hi - i just found this thread on the internet and now am totally engaged in finding the parts to build my own projector with. right now the most problems i am having are coming from deciding what lcd(s) to use. how big of an lcd do i really need and what are the benefits of having an lcd for r,g, and b? is the image that much better? i found a 4" lcd with driver board from earthlcd for only $150, and another 4" with board from partsexpress for $100 - both look pretty tempting. all im looking to be able to do is use my projector for ntsc sources, so im not really concerned about being able to do vga.

thanks

jeff
 
#92
What you want to try to do, at least, is find an LCD with the smallest pixel size, and most vertical and horizontal pixels per screen.

3 Monochrome screens w/ RBG light for each would yield richer colors and brightness. But then you have to deal w/ alignment issues. It may be worth it though.

Part of the idea around this project is to make a projector yourself and save some cash. Light source longevity is an important factor for me.

Let us know what you find.

Good luck!

Vince
 
#93
i guess what i really want to know is: will tapes off of my vcr look like crap when projected on the wall if the lcd i am using is only 383*234? i would also like to be able to do some stuff with my computer which has a scart port for hooking up an lcd - are there any ntsc converters out there for them?

thanks


Jeff
 
#94
Even with 800x600 resolution you'll get a screen door effect. This is 3x better then what you're stating for your LCD screen. Text will look jagged w/ lower resoutions. 383x234 isn't great. I tested w/ 960x234. I could still see the individual pixels. But from about 8 feet from the screen, it wasn't horrible.

Using a convert will only work if there is an input on the LCD which accepts a higher resolution, for example, S-video, R-G-B component, or 15-pin digital output from a PC. The latter can be converted to analog video. (See other parts of this thread.)

E.G., I have an 8" 640x480 LCD w/ digtal and S-Video inputs, I can raise it to 800x600 with the correct input.

Composite is a combo of R-G-B.

To answer your question, It's not great, but you'll get used to it. With any of these available LCDs, don't expect the best resolution.

There is a company called Crystaloid. I can give you the reps name and address. They have a hi resoution 1.8" screen w...

Crystaloid Technologies, Inc. does offer a small color TFT module PN- TFT0189H

* 1.8" high
* 180 Nit
* Pixel W x H = 528 x 220
* Operating Temp. 0 to 60* C
* Includes Driver Board

1 through 99 pieces = $125.00 ea.


Please contact me directly if you would like further information.

Best regards,


Jeff W. Giles
Regional Sales Manager
Crystaloid Technologies Inc.
Ph 330 655 2429 x285
Fx 330 655 2176
e-mail jgiles@crystaloid.com

Hope this helps,

Vince
 
#96
Either 1 color or 3 monochrome LCDs. Mostly 3 monochrome LCDs.

They are not the costly parts, however. Lenses and the light source cost the most. Some replacement light sources cost $500 or more, and some less, but don't last as long as the more expensive Metal-Halide or Xenon bulbs.

Vince
 
#97
I'm all questions, and all excited about this.

But what are all the components I will need for this project?

Can someone draw up some rough sketches on how everything would be placed approximately?

I'm sorry about all this trouble, I'm new to all this stuff, but getting a projector made would just make my life complete =D
 
#99
This is great

Are there any pictures yet? I've often thought about using the ultra-Bright LEDs to replace standard lights, but this project takes the cake. The more infomation you're able to release on this the better, I know alot of people would appreciate having a solid foundation to start their own projects with. It's still quite a bit of money for a lot of us to throw down, so the more we can be assured of what already works, the better.


This link is interesting, if not entirely useful:

http://ledmuseum.home.att.net/ledleft.htm

I'm wondering if using a 320x240 aspect ratio screen would be better than the 938x200(or whatever it was) that you said you were using. I'd also like to figure out if using a screen from an older pocket tv would work well, since they can be found fairly cheap.
 
#100
Finding a LCD module is not a big problem any more. If you want a tuner in it is another story.

I can't stress enough the importance of finding an LCD with the most and smallest pixels.

I have no pictures yet, myself. I have to rebuild the enclosure because I'm dealing with a larger screen and the electronics boards are bigger.

Once I build something workable, I will post. I have all the parts, it's just a matter of getting it all together.

VInce
 
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