Toshiba 40h80 - faint horizontal "lines" visible in bright areas?

Discussion in 'Archived Threads 2001-2004' started by Marc Carra, Sep 15, 2001.

  1. Marc Carra

    Marc Carra Supporting Actor

    Joined:
    Aug 31, 1997
    Messages:
    767
    Likes Received:
    0
    Trophy Points:
    0
    Hey everyone,
    I've had my 40h80 for about 6 months now and and it tweaked to perfection. Well, almost perfection. I've come to notice that in brightly lit scenes where there is white or a light color, faint horizontal lines are barely visible. Has anyone else noticed this? Am I seeing the pattern of the lenticular screen? Any ideas?
    Marc.
     
  2. Elliott Willschick

    Elliott Willschick Second Unit

    Joined:
    Dec 1, 1998
    Messages:
    333
    Likes Received:
    0
    Trophy Points:
    0
    I have the same set and the same problem. Supposedly it is a flaw in the line doubler. I have been told, by Toshiba, that it can be avoided by using a progessive scan source which bypasses the doubler. I couldn't confirm this when I posted a message a few weeks ago but it is very annoying.
     
  3. Marc Carra

    Marc Carra Supporting Actor

    Joined:
    Aug 31, 1997
    Messages:
    767
    Likes Received:
    0
    Trophy Points:
    0
    Elliot,
    I'm using a Panasonic RP91 progressive scan player, so Toshiba's explanation doesn't hold any truth. Since you have the same problem, it must be some sort of set anomoly. I'm going to do some digging, and If I find out the cause, I'll let you know.
    Maarc.
     
  4. Elliott Willschick

    Elliott Willschick Second Unit

    Joined:
    Dec 1, 1998
    Messages:
    333
    Likes Received:
    0
    Trophy Points:
    0
    That does finally answer my question. I wanted to upgrade my speakers but I would have bought a pgrogessive scan player if it solved the problem first. If you search at www.hometheaterspot.com you find some info on it.
    Toshiba's offical stance is that it is a desgin flaw in the line doubler. One of their techs claimed that they fixed it by rearranging all of the wires but this took hours and they weren't sure exactly what they did.
    Keep me posted.
    Thanks
     
  5. StephenMSmith

    StephenMSmith Stunt Coordinator

    Joined:
    Apr 29, 1999
    Messages:
    85
    Likes Received:
    0
    Trophy Points:
    0
    Are these lines stationary or moving? Are they visible throughout the whole screen?
    Steve
    ------------------
     
  6. l e j u n

    l e j u n Auditioning

    Joined:
    Sep 5, 2001
    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    0
    Well I have had the Toshiba 43H70 for about two weeks now.
    It has looked absolutely fabulous (after a little tweaking with Video Essentials) since I bought it.
    But within the last two nights I have noticed the same problem you speak of. It is very annoying. I was watching Memento this evening and I could barely keep focus on some scenes because I kept getting distracted (I kinda related to Lenny ^_^).
    I thought I finally found the right TV for me. I was so happy. Now I am not so sure.
    l e j u n
     
  7. Sean_S

    Sean_S Auditioning

    Joined:
    Jan 2, 2001
    Messages:
    13
    Likes Received:
    0
    Trophy Points:
    0
    If the lines appear to shimmer, then you might be pushing the digital convergence board to the limit of its range.
    I would venture to guess that you've reduced overscan quite a bit. If you reduced overscan with HIT and WID, then reconverged to the templates, this would cause it.
    You can tell if you stressing the DC board simply by entering convergence mode and moving the points where the effect is occurring in toward the CENTER of the screen. I.e, if the effect is in the upper left, move the associated points down and to the right. You should see the effect disappear. If that is the case, you will need to increas HIT and width, then move the convergence points in.
    However, if you can't see the effect in convergence mode, none of this applies.
    Just my $.02.
    Sean
    ------------------
     
  8. Marc Carra

    Marc Carra Supporting Actor

    Joined:
    Aug 31, 1997
    Messages:
    767
    Likes Received:
    0
    Trophy Points:
    0
    Steven,
    Yes, they are stationary, across the whole screen.
    Sean,
    I haven't adjusted the overscan on my set. I have done some minor service menu convergence adjustments , but nothing major. I don't think the effect appears in convergence mode. It's only noticable on bright backgrounds and areas.
    Marc.
     
  9. StephenMSmith

    StephenMSmith Stunt Coordinator

    Joined:
    Apr 29, 1999
    Messages:
    85
    Likes Received:
    0
    Trophy Points:
    0
    Since they're stationary, you could just be seeing the ribs of the fresnel screen. I can see these ribs from my viewing distance on solid light-colored backgrounds.
    What about if you toggle back and forth b/t full and TW2 modes? Do the lines change at all? If not, it's probably the ribs.
    Steve
    ------------------
     
  10. Mark Bendiksen

    Mark Bendiksen Screenwriter

    Joined:
    Mar 16, 1999
    Messages:
    1,090
    Likes Received:
    0
    Trophy Points:
    0
     
  11. Brian_J

    Brian_J Second Unit

    Joined:
    Mar 3, 2001
    Messages:
    418
    Likes Received:
    0
    Trophy Points:
    0
  12. Marc Carra

    Marc Carra Supporting Actor

    Joined:
    Aug 31, 1997
    Messages:
    767
    Likes Received:
    0
    Trophy Points:
    0
    Brian,
    That posting at the HT Spot pertains to an entirely different problem. These are horizontal lines, not the vertical ghost lines that almost every Toshiba set seems to have.
    Marc.
     
  13. Elliott Willschick

    Elliott Willschick Second Unit

    Joined:
    Dec 1, 1998
    Messages:
    333
    Likes Received:
    0
    Trophy Points:
    0
    I just thought I would update that I seem to have improve the lines a bit on my set. When I was watching Cast Away I noticed the lines horribly during night scenes. It was like watching the movie thorugh a jail cell because the lines were about an inch thick.
    I decided to unhook everything and see if I could see it on the black background on the video inputs with the contrast turned up. I noticed the lines were much smaller but there was some interference. I took the my cable tv cable and put it aside as well. When I hooked my DVD player back up I found that one of the cables, the blue component one, was making the lines worse. I replaced it and now the lines are about pencil thickness and the only one I notice is the on to the far left.
    While this is still not great, the problem has been reduced. I wish Toshiba would look into fixing it because it is an embarrassment when other people see you spend so much on a tv with lines on it [​IMG]
     
  14. Allan Jayne

    Allan Jayne Cinematographer

    Joined:
    Nov 1, 1998
    Messages:
    2,404
    Likes Received:
    0
    Trophy Points:
    0
    The ribs of the fresnel screen are concentric circular grooves with a spacing of about 0.5 to 0.7 millimeter, not horizontal. The purpose of the fresnel screen is to take the rays of light ever spreading outwards from the projection lens and turn them all roughly parallel out towards the viewer. Then the lenticular screen, with myriads of upright ribs, takes some light from each spot (pixel position if you insist) on the fresnel screen and sends a little bit to the left, a little bit to the middle, and a little bit to the right so people on the sides get a reasonably bright picture.
    Are these lines as thin as scan lines? At a slight tilt compared with the picture scan lines? Roughly evenly spaced perhaps an inch apart? A coupla' dozen of them (progressive scan)?
    Maybe scan lines 481 - 525 are starting to show up as the electron beam returns to the top of the screen. This requires an adjustment (electronic matting) or repair.
    More: http://members.aol.com/ajaynejr/vidfres.htm
    [Edited last by Allan Jayne on October 25, 2001 at 06:36 AM]
     
  15. Rachmat Hartono

    Joined:
    Oct 23, 2001
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    0
    I have horizontal lines during bright scenes as well in my 56h80. I posted this question previously in another forum and no one seems to have the solution to this. The horizontal lines are not scanlines. They are thinner than scanlines and they are static. If you look at them closely, they appear to be red. They are everywhere in the screen, but they are more visible during a moving bright scene since the lines are static and the scene is moving. They appear in all inputs as well. I have seen many toshiba xh80 in many local store and they all have these lines. I hope someone has a solution to this issue, otherwise, I guess we'll all have to live with it. It's somewhat annoying once you notice them.
     
  16. Andrew Beacom

    Andrew Beacom Supporting Actor

    Joined:
    Jan 11, 2001
    Messages:
    792
    Likes Received:
    0
    Trophy Points:
    0
    I think we have more than 1 issue/problem here. I personally can see horizontal lines on my 50H81. I was worried until I decided they were the 'ribs' on the lenticular screen. I'm only sat 8 ft away so I'm technically to close. Once I knew what it was I became less concerned.
    Now I do have those Vertical ghost lines and some ringing. But that's a different story.
     

Share This Page