DIY Video Projector

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snoogans,

Is the converter you mentioned a card for a computer? If so, I plan to use my projector for DVD video only, without a computer. I don't have a computer that is fast enough to handle video, so that would add big $$$ to the price tag of my projector.

If it is just a standalone adaptor for $30, please let me know about it...I just didn't think such a thing existed.

Thanks for the tip.

-f4
 
CRT route

Scot_lad or any one else for that matter . . .

If You are still on this thread, I remember a while back when I whas repering a monitor I notised that the paint on the CRT had pealed of and I could see in to it . . . . . is it posible to get more brightness by shining a lightsourse in from behind the fosfor and boost the brightness?

By for now
 
CRT route

To contine with my previouse post, if it is possible, do I need a point lightsourse like the LCD-projector needs to keep the sharpness or can i use a spredd out lightsourse like a flouresent light?

I guess I need to try it for myself becouse I do not think annyone have tryed it . . . . .

By for now
 
Back again

Hello,
Well I've had to catch up a wee bit. My flu that had me stopped posting last week got me in hospital, it wasn't flu at all. So now I'm back and in recovery off work til next week, so I may have some time to play with the toys. Let you know soon.

A quick word about the coating on the outside of the CRT tube- dont' go picking it off. Some manufacturers make it conductive, in order to produce a capacitance effect with the coating on the inside of the tube, so you can get a big nasty shock from it if you're not careful.

As for shining a light on the inside of the tube. The contrast of the CRT depends on the darkest dark it can make, which is however dark a phosphor is when it's not glowing. Now, imagine there was a big light bulb inside the tube, which was glowing. If the CRT was switched off, you could still see the glow through the front of the screen. Put these two things together, and you can see that the darkest dark with a light shining through the back of the screen, isn't very dark at all.

And the phosphors glow to produce the image, any other light not coming from a phosphor would simply distort or rubbish the image.
 
CRT route

Scot_lad

Well my theory whas that by doing this I could brighten up the hole image whitch is exactly what I wont becouse the hole image is losing brightness when projected on to a larger surfise and so should get the right brightness back by this . . . . . .

Anyway, I do not want to lose the sharpness and not the other stuff either so back to boosting "the electronic way" . . . . .

Thanks Scot_lad! Saved me a lott of work for nothing 🙂



By for now
 
Just a historical note:

There is a technique to project electron beam modulated images called Eidophor, but its not used anymore. (to complicated!). The electronbeam hits an oily surface and the impacts make little deformations. These deformations generate the videoimage, which is illuminated and projected by a bright lightsource. The projection-type is called 'dark-field-projection'. (Dunkelfeldprojektion, word by word translation).
But this won't be surely something to DIY!

xblocker
 
VP140

Got my VP140 last night...looks like it has an achellis heel, as far as moving the panel driver boards out of the way...

These photos will show the drill down to the problem. Here's the unit out of the plastic case -
 

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