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Discussion Starter · #1 ·
When I test with a single white pixel on a black background, I can see that the colors are off with each other. The blue is a bit to the right and the green a bit to the left. Somehow they still form a white pixel in the middle, but there is alot of spread. Do you know what I mean? Is there a way to adjust this or anything that will help?
 

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can't adjust convergence. I am guessing it could maybe go back to the factory and they could realign the panels.


do you notice the problem from your seating position? if not, I wouldn't worry about it.
 

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If you are still in warranty then send it back.

It can be done but you will most likely need the service manual to clarify what the individual adjustments are.

I fixed the convergence on my PLV60 and it took about 25 mins.

I wanted to have a go at the blue panel focus as well but the adjustments screws were buried too deep into the optical system so I decided to live with it. I wouldn't have tried this without the manual. I also wouldn't have tried this if the projector was still in warranty.
 

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Discussion Starter · #4 ·
It's not in warranty. I have the manual, but it is very small and says nothing about internal adjustments. I have opened it up before to have a look around and it looks like the lcd panels might be accessable, barely. What should I be looking for to adjust? A screw or something?
 

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Discussion Starter · #5 ·
Any update on this? I'm totally willing to open this sucker up and go at it. I just need some guidance... what to look for.
 

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Adjusting the convergence would be a VERY delicate job.


Example: If a SVGA projector 1" panels is horisontally 1 pixel out of convergence on the blue panel it would need to be moved just 1/800". It's not something you can do easilly at home. Though nothing is impossible. :)


Ad far as I know the Sanyo PLV60 has a kind of digital convergence adjustment where the colors can be shifted digitally on the panels without any physical movement. Correct me if I'm wrong. The service-manual of my Hitachi states that the panels can't be adjusted separately, the whole prism/panel assembly will have to be replaced.


Are you absolutely sure the offset pixels are blue and green, and not blue and yellow? Blue and green would mean both the blue and the green panel is out by 1 pixel. It's weird though that you have a white pixel in the middle becasue it shouldn't be white if the blue and green are not projecting through that pixel, it should be red.



Tor Arne
 

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See if you can get a service manual for your projector. I have a (very) old Sharp XV-H30U with the service manual because at the time, no one at the huge service center could do the adjustment. A service center or the manufacturer should sell you such a manual.


As some info on mine, one panel is fixed (green, I think) the other two have set screws that lock the panels into place. Once those are loose, you can adjust each panel in X, Y and theta (rotation). I used a piece of dark paper to block out the red while I adjusted blue and vice-versa.


I also had to do it in short intervals because the unit was designed to have air flowing through the case, and I had to defeat the sensors that shut off the projector with the case open and it got warm pretty quickly.


But I got the unit converged within 1/2 pixel in the center and one pixel at the edges after emitting a few curse words and some very steady hand movements. Have some compressed air handy as well so you can keep the panels dust free. Any small speck on them will appear on the image and the panels are not protected very well because people are not supposed to get to the innards. (No, do NOT remove the panels and clean them with glass cleaner! Not even optical quality!)


Let us know what happens and best of luck,

Chris
 

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Discussion Starter · #8 ·
maybe just the lens is crap? It looks like there is the correct pixel in the center, then the blue kind of smeared to the right and the green/yellow to the left. Could it be that the lens is not very good, therefore not converging perfectly? Giving a slight prismatic effect?
 

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It's not likely the lens. All lenses diffract light of different wavelengths at different angles, but that should either already be handled by the optics in the machine or it's small enough to ignore, or both.


Here's what my manual says on the matter: "Make the X, Y and theta adjustments for the red and gree colours. Keep an error within 0.5 dot at the center and within 0.8 dot in the circumference."


That is to say, every single technician who sees that the red, green and blue dots that make up the one white dot in the center all overlap by half the size of the pixel in the center of the screen, and by at least one fifth of a pixel at the edge will say the unit is in perfect convergence, or at least up to factory specification. "Perfect" alignment is really impractical.


I'm sorry to say white next to black will always have a colored edge. It's even true of laptop LCD panels because red green and blue never overlap at all, but then they never move relative to each other either. It happens on plasmas and direct view CRT's too. The colors just don't overlap.


Maybe it's just time to accept the imperfection and move on. Don't look at a display of single pixels anymore. :)


Adding to tahustvedt's comment, 1/800" will move a panel an ENTIRE pixel. You want to move it, what, one tenth of that?


Be at peace, brother.


Chris
 

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Discussion Starter · #10 ·
I see.


I guess I should consider that my projector really isn't broken. Only permanently, yet subtly, imperfect. Moving something 1/8000" really is a daunting task. Thanks for the advice.


One last possiblity I thought of:

The lens is creating halation. I will try experimenting by placing a donut in front of or inside the lens to filter it.
 

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Quote:
Originally posted by Torginator
It's not likely the lens. All lenses diffract light of different wavelengths at different angles, but that should either already be handled by the optics in the machine or it's small enough to ignore, or both.
Don't you mean "refract" and not "diffract"? Diffraction is a different issue that deals with light rays' paths bending outwards as they pass through a small aperture. The aberration you are referring to is caused by the lens glass having different refraction indexes for different wavelengths of light. Good lenses can correct for this to some degree (they are tagged "Apochromatic") but I'm not sure how good lenses on ultra-budget pj's are. I know my stupid "featherweight" glasses cause more chromatic aberrations than I'd care for. Not to mention the geometric distortions, which at one point I thought were the fault of my ae300's lens =P


Sorry to pick semantic hairs, but you never know how many college kids there are out there who have a physics test in the morning :)


Mike U.
 

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Quote:
Originally posted by mulveling
Don't you mean "refract" and not "diffract"?
You are quite correct, Mike. Refract is what lenses do. Diffract is what light does near the edges of objects.
 

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i have an old philips 4650 and on the right side all three colors are off.. only about an 6" to a foot of the 64" width from top to bottom. I have had my machine in the shop 2 times once for the convergence to be fixed which was basicly them replacing the trough(sp?) cost you ask? 495 flat rate then 197 for parts.. second time was the balast blew oh and guess what?? 495 flat rate and then another 197.. cant wait to get a new projector.. only paid 800 for the projector and love it no cool down time which i think might be the cause for the problems.. =(
 
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