Burn-In Question for Different Types of Displays (long)

Discussion in 'Archived Threads 2001-2004' started by David J Wang, Nov 26, 2001.

  1. David J Wang

    David J Wang Agent

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    Want to know how likely and how long would it take for burn-in to occur on this list of different displays for a variety of video sources. No stretching or manipulating of the image is allowed if it distorts the image (ie 4:3 content in stretch mode for widescreen RPTVs) unless the video feed is intended to be manipulated (ie DVDs in 16:9 mode on a 4:3 TV).

    The list of displays to compare would be:

    1) 4:3 Direct-view TVs (I'd assume HD capable and analog would have the same burn-in behavior, correct me if i'm wrong)

    2) 16:9-Widescreen Direct-view TVs

    3) 4:3 CRT RPTVs

    4) 16:9 CRT RPTVs

    5) LCD 16:9 displays (not projectors)

    6) DLP 16:9 displays (not projectors)

    7) Plasma 16:9 displays

    8) LCD 16:9 projectors (same burn-in behavior as LCD displays?)

    9) DLP 16:9 projectors (same burn-in behavior as DLP displays?)

    The video sources to be used for burn-in testing would be:

    A) 4:3 Television feeds (satellite,cable)

    B) 16:9 Television feeds (satellite,cable)

    C) 16:9 DVDs

    D) 4:3 gaming (Xbox, Gamecube, PS2, etc)

    E) 16:9 gaming (Xbox, Gamecube, PS2, etc)

    I really need the scoop on burn-in behavior for all these displays because I play a lot of games. I know you can get around burn-in with RPTVs with adjustments to contrast/brightness and taking breaks from playing games but I just don't want to deal with any fiddling or adjustments.. period. If adjustments are required for the other displays as well then I probably wouldn't mind getting an RPTV, but I'm looking for a display where realistically in regular use I wouldn't have to worry about burn-in at all. Need honest, objective, descriptive answers. Will be an expensive purchase so please .... need help!
     
  2. David J Wang

    David J Wang Agent

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    No replies at all? Please.... I need any help.
     
  3. Mark Rogo

    Mark Rogo Extra

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    LCD displays cannot suffer burn in, nor can LCD projectors. DLP projectors and displays are the same.

    CRTs and plasmas can suffer burn in.

    Mark
     
  4. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    Actually ... LCD/Plasma and DLP can all suffer from uneven wear as well. For a short time, there was an urban myth going around saying that this does not happen to these types of displays. But it does as well.

    There is no time table because it depends on how much you use it and the type of programming you use the display for. As well as your viewing environment and the viewing habits.

    So it could be from 5 months to 12 months to years from now ... who knows.

    Regards
     
  5. Jaehoon Heo

    Jaehoon Heo Stunt Coordinator

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    Hi Michael,

    I heard that displaying 4:3 material on 16:9 screen cause most serious problems, while 16:9 material letterboxed in 4:3 screen cause relatively minor burn-in. Is this true?
     
  6. RyanDinan

    RyanDinan Stunt Coordinator

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    No, that's untrue.
    Whenever you don't use the entire CRT surface (whenever you see black bars ANYWHERE on the screen), you can suffer from uneven phosphor burn. This even applies to 16x9 widescreen TV's displaying 2.35:1 movies. To minimize the risk, make sure your contrast and brightness are calibrated correctly, and try to watch a good mix of material - meaning, fill that screen from time to time [​IMG].
    -Ryan Dinan
     
  7. David J Wang

    David J Wang Agent

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    But does it take a longer time in general for Direct-view TVs to burn-in than RPTVs or Plasma?
     
  8. RyanDinan

    RyanDinan Stunt Coordinator

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    Yes, typically, direct-view sets take longer to suffer from phosphor burn than RPTV's, since they don't have to burn as bright to create the same light output. I'm not sure about Plasmas really.....However, I do know that they're just as vulnerable to uneven wear as a CRT-based display.

    -Ryan
     
  9. Mark Rogo

    Mark Rogo Extra

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    Michael knows more than I will learn in a lifetime. But I disagree with his statement that LCD and DLP can burn in. They can't.

    Burn in essentially is the result of uneven phosphor wear. This is inherently a risk with CRT and, unfortunately, my beloved plasma.

    LCDs use a grid of transistors. It's a solid-state device. The backlight is either all on or all off. It can dim over time, but an individual pixel cannot. LCDs, if they display a static image for hours, can have a little bit of transistor latency. But that will clear up if the device is shut off for a while.

    DLPs use a grid of mirrors. Again, the fundamental nature of these mirrors, like transistors, is that don't change over time. The light (in DLP it's a bulb) is also all on or all off. It burns out, but not individual pixels.

    Now, an individual transitor can fail in an LCD and an individual mirror can fail in a DLP. I've never heard of the former happening unless it's right out of the box. With DLP, I could see it since the device is electromechanical in nature.

    But that is NOT burn in. You will never see an old LCD display with, say, the Windows Start logo burned in.

    The way in which burn in occurs simply cannot happen on relfective or transmissive displays of this time. Phosphor based displayed, where individual phosphors make up the picture elements, are susceptible to burn in. Some claim plasma is more so than CRT, some claim less so. I'm inclined to believe and hope it's less.

    Mark
     
  10. Guy Kuo

    Guy Kuo Supporting Actor

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    Michael refers to a memory effect which can affect LCD displays. It isn't a permanent effect like that which happens with emissive phosphors. Basically, the liquid crystal displays work by using electrical forces to align liquid crystal molecules into a coherent direction which causes a predictable and controlled polarization of light. Combining that with crossed, fixed polarizers, light filters and a light source allows one to create the color images we see on LCD's. The one part of this which gets forgotten is that the relaxed, incoherent state of the liquid crystal must be returned to after the control charges are done. If a LC panel holds a portion of the liquid crystal in the coherent state (black on screen) the liquid crystal material can temporarily develop a tendency to stay in a more organized manner than normal. Thus long term black on a LC display may create an area which holds a persistent image effect that looks like a phosphor burn. Fortunately, if the LC panel is allowed to be quiescent (off) for an extended time, perhaps one or two days, the liquid crystal regains its normal characteristics. The effect reverses and the apparent "wear" or "burn" goes away. Another mechanism I've run across, but haven't verified, is a temporary charge problem on the driving transistors. Again leaving the panel off corrects the problem.
     
  11. Mark Rogo

    Mark Rogo Extra

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    Guy, thanks for that detail. If you read my post, you'll see I pretty much said the same thing, although less eloquently:

    "LCDs, if they display a static image for hours, can have a little bit of transistor latency. But that will clear up if the device is shut off for a while. "

    That said, it is NOT burn in, which is permanent. My plasma, for example, may well be susceptible to burn in. I hope not too much, but who knows. On the other hand, it is susceptible to a bit of faint after image if I use 4:3 with bars for too long. I can see a slight "line" where the bars were on top of the widescreen image (when I stop using the bars and go back to widescreen). I suspect this is because of the odd contrast of the bars vs. the picture.

    Regardless, the line disappears after a short while. Also, the white-bar scroll on the Panasonic seems to clear it away in just 15 minutes of use or so.

    Finally, are you the same Guy Kuo who used to overclock Macintoshes in the early-to-mid 1990s?

    Mark
     
  12. Guy Kuo

    Guy Kuo Supporting Actor

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    Yes, that was I.
     
  13. Dave Miller

    Dave Miller Supporting Actor

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    David, I hope you don't mind if I jump in here and ask a question: Is burn-in input specific on a RPTV? Or once you get burn in, is it noticable accross all inputs? I'm trying to determine if burn-in is beginning on my Tosh 65h80. I only notice it while watching cable and only on the left side of my screen.

    Peace,

    DM
     
  14. andrew

    andrew Auditioning

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    Dave,

    burn in is physical damage to the CRT(s) of the device. The phosphors are basically "worn out" in areas that have been used more than other areas. This means that once you have burn in you have burn in all the time. Take a look at an old monochrome CRT display that has been used for a display like a point of sale often you can see the "default" screen displayed by the software burned in so badly that you can read the screen when the actual monitor is turned off!

    This would be the same for say a CRT projector, once burned in the problem could be visibile with no input at all

    Andrew
     
  15. MarkDesMarais

    MarkDesMarais Stunt Coordinator

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    Mark-

    Hate to be the bearer of bad news, but plasma will definitely burn in. It has phosphors, so it is susceptible in the same way as any CRT device. We used to do a lot of flat panel work- all the panels at the NYSE came out of our company, including the plasma crowd displays (the big guys overhead at the kiosks). They burn in like crazy- in fact the exchange runs inverted video on them all night just to keep them even.

    Markd
     

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