DIY Video Projector Part II

[jason_ehl]

Guy,

If you are game can you drop me a line.

I can give you the exact details of the project...as well as forward you a layout drawing to clear up what I really need to do.

After a few days of rethink I have a few options that may seem feasible...but the lense portion of this project is not my strong point.

Jason

[El_Gordo]

For all that are interested in building a cheap and small projector, I've finished the trial en error stage of my 2.5" LCD with an array of 48 super bright white LEDs as light source.
here's the list:

50 super bright leds 80,000 cmd, from besthongkong on eBay $ 13.90 deleivered
30 resistors from radio shack $ 9.00
2-Action TFT 2.5" color service monitor, eBay $ 160.00( I still have one if someone is interested)
1- predrilled pc board from RadioShack $6.00
1- Rear TV projection Lens 4 1/8 diameter, free( I found 1 broken tv on the street and pulled out the lenses, lucky me!)

and the rest is pieces of wood and screws from Home depot $ 25.00


photos coming soon!

write me if you want

irwing69@comcast.net

[ret2xanadu]

I made a neat little projector using a 4" b&w toshiba TFT which has a resolution of 35k. Instead of a crt lens I used a f1.2 super 8mm lens. For light I used a 35w 3000lm HID lamps with ballast that I had laying around, along with a reflector from a 1m candlepower spotlight. I used white posterboard for the screen. The results were not bad. Contrast was good. It was pixelated but that made it interesting and unique.

It was fun but now I've bought an Infocus projector. If anyone's interested you can buy my 4" LCD from me which has both wired or adapter for power, video in, audio in, brightness and color. for $20.

[ret2xanadu]

and it looks like this
http://i22.ebayimg.com/01/i/02/19/80/ad_1_b.JPG

[elstcb]

Originally posted by El_Gordo
For all that are interested in building a cheap and small projector, I've finished the trial en error stage of my 2.5" LCD with an array of 48 super bright white LEDs as light source.

Cool, I'd be interested to know what sort of brightness you get from it, I suspect you have to be in quite a dark room or seriously restrict the screen size (probably not a bad thing with an lcd that small). Also what sort of heat do they give off with your configuration once enclosed in a box? How does the colour temperature compare to MH, etc.?

I've never doubted LEDs as a light source but the cost has always been a bit too much, seems like you've made something you're happy with for next to nothing which is always good!

[Sheoul]

excellent information this forum is very helpful

[linuxenthusiast]

I can't find a power supply for my nView Z350 anywhere, so No I'm using an ATX power supply which run the Panel just fine, except it heats up after about ten minutes and then the video gets distorted.

The model number for the original power supply is BPA-353-N, and has the following voltages:

Volt / Amp
+5.9 3
+12 1.55
-12 0.27

The one I'm using has the same voltages but quit a bit more amps than that, and I'm not sure if that's what causes it to heat up.

Has anyone been able to successfully run an ATX power supply on this panel or does anyone know what the issue is?

[Dantx101]

I hope I'm posting this correcting and not hijacking a thread. If so please let me know and I'll not make the same mistake again.
But hopefully someone could answer a question for me.

I'm in the process of collecting parts to build a projector based on a 15" LCD.
I happened to be doing some Christmas shopping at a local electronics store and couldnt resist picking up this lens for $20.00 and am curious whether it could be incorperated in my project.

Its a Sharp AN-LV40EZ, I just checked the web and its listed on B&H photo for $2500.00, which of course doesnt mean it will work but if it doesnt I'm only out $20.00

The specs I've found out so far are
* Type
* Wide-angle zoom lens Zoom, Wide angle

* Lens aperture
* F/1.7-2.1

* Focal Length
* 74 mm 97 mm

* Optical zoom
* 1.3 x

* Zoom adjustment
* Motorized drive

* Throw Ratio
* 1.9-2.5:1

* Projection Distance for a 100" Screen
* 13.8 ft - 18 ft

This thing is a monster at 11.25" long. Rear lens Diam of 3.5"
Front lens diam of 4"

Any thoughts would be appreciated

[Guy Grotke]

With that short a focal length, the LCD will have to be very close to the back of the lens. So the LCD could not be much larger than the lens diameter. Perhaps the FOV will be wide enough for a PSone 5" diagonal LCD. Try some experiments with printed transparency film, the lens, and a spotlight to see how large an area you can project over the real throw distance you want to use.

For a 15" LCD projector, you need a lens with a much longer focal length, just so you can put it far enough from the LCD so that the FOV covers the entire LCD.

Standard lens & matching fresnel sets:

300 mm fl overhead projector triplet with 220 and 330 mm fl fresnels
450 mm fl opaque projector triplet with 220 and 550 mm fl fresnels

[Dantx101]

Thanks for the reply Guy. Looking at the machine it was used in I was afraid of that.
To make something like this work I would either have to modify the lens or create a way narrow the focus point of the lcd screen or as you say use a smaller screen which would lose resolution. Both mods are outside my skill level right now, back to using the triplet after Christmas