What is convergence? How can you go about fixing this problem?

Discussion in 'Displays' started by kurt_fire, Jun 5, 2004.

  1. kurt_fire

    kurt_fire Stunt Coordinator

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    i have no clue what convergence is. i'm looking into purchasing a 42" samsung HDTV later in the week and I've read about this TV having convergence errors...what exactly is this??

    are these convergence errors easy to fix? also, does this TV require any tweaking in it's service menu?
     
  2. Steven.W.T

    Steven.W.T Stunt Coordinator

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  3. kurt_fire

    kurt_fire Stunt Coordinator

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    ok man i watched those videos but they really didn't tell me how I could go about determing if my soon to have HDTV is having convergence errors or how I can can fix them.

    would they be easy to fix with a samsung 42" hdtv?
     
  4. Steven.W.T

    Steven.W.T Stunt Coordinator

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    Yeah I dunno, I'm new to this, sorry. Those videos just showed you what convergence is though.

    Anybodu who actually have experience wanna help?
     
  5. ChrisWiggles

    ChrisWiggles Producer

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    Well, a CRT-projection television, be it front or rear projection, works by having three picture tubes (guns). Each is one color primary: red, green, blue. The guns are aimed at the screen (the red and green are off-center, and are angled in) physically, to attempt to align the images from each tube. To create a white point on the screen, all three colors have to align perfectly. If any color is off just ever so slightly, you will have a white line or point with colored fringes, etc. OBviously, you can't get things perfect with just physical aim of the guns, not even close. Convergence allows you to manually, using a convergence grid and electronic compensation, adjust the image position on each tube face very accurately to match up the entire grid on the screen, so that across the whole screen all three colors are perfectly aligned. The key to getting thigs stable and long-lasting is to have good gun aim, and to use the most coarse adjustments first, like geometry, etc, and using the finer convergence adjustments as a last resort.

    Digital displays, of course, do not have convergence errors, at least not in the same way. Single-chip DLPs do not have convergence errors, though you can think of rainbows as a type of convergence error, but in the time domain instead of physically.

    Three-chip DLPs, and LCDs, each panel has to be perfeclty aligned, and often they are not, but usually this can't be fixed anyway without factory service. I hope that makes sense!
     
  6. ChrisWiggles

    ChrisWiggles Producer

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    Sorry, red and blue are off center, green is in the middle. duh! :b
     

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