Most iphone4 have fine horizontal interlace onscreen (with a test picture)

Discussion in 'iPhone' started by troyyy, Jul 28, 2011.

  1. troyyy, Jul 28, 2011
    Last edited: Jul 28, 2011

    troyyy macrumors newbie

    Joined:
    Jul 28, 2011
    #1
    Hi all,

    I have noticed some very fine horizontal lines on my iphone4 screen with IOS 4.3.5,Its not as silky smooth looking as it was.

    they are very fine unless you look carefully you can see a lot of thin horizontal lines on the entire screen.It is a very persistent flicker with flashing horizontal lines on the whole display.

    Do you guys have this problem?If you can‘t see it ,use this picture to test it.Save this picture( Full-size image with 640*960,not the Thumbnail) to you camera roll or photo libray,then check it without Zoom in or out,you would see the top and bottom bar flickering.

    I found that some guys have the same problem
    https://discussions.apple.com/message/13236194#13236194
    http://forums.macrumors.com/showthread.php?t=995716

    I dont know Whether its the hardware or software problem,but its the most obvious when unlock the screen.After keepping the screen on or play some video ,it may disappear.
    [​IMG]
     

    Attached Files:

  2. psonice macrumors 6502a

    Joined:
    Jul 22, 2005
    #2
    Wow, you're right. I can see clear interlace flicker when viewing that at actual size. Very curious, wonder if they're drawing alternate lines to keep performance high on the high res screen?

    Not that it'll make any difference at all 99.9% of the time of course. The effect is slight, and only visible with a test image like this or under very rare circumstances. I mean I'm pretty sensitive to this and can see the screen flickering clearly with that image, but I'd never noticed before now.
     
  3. troyyy, Jul 28, 2011
    Last edited: Jul 28, 2011

    troyyy thread starter macrumors newbie

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    Jul 28, 2011
    #3
    hi, psonice

    The test image just make you see the interlace flicker more clearly,If the test image flickers on your iphone4 ,you definitely have this issue.Actually,if you are sensitive enough and see carefully at the top bar ,especiall on the lockscreen date bar,you would see fine horizontal lines ,even that you can see the horizontal pixel.The impact is that the screen is not sharp enough as a "retina display"

    What I am wondering is that they seem to go away after the phone has been in use for a little while and "warms up". Is that a hardware issue?It seems more like software issue.
     
  4. Kyotoma macrumors 68000

    Kyotoma

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    Nov 11, 2010
    Location:
    Carnegie and Ontario
    #4
    I have no idea what you guys are seeing. I don't see any flicker when I view this image.
     
  5. Shakko macrumors member

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    Apr 14, 2008
    #5
    So happy I am not the only one facing this. I thought either me or my eyes were going crazy for sure.

    I definitely see flickering on my display with this image. What is weird is that I never saw this issue on my old iPhone 4 (bought about an year ago). I've only started to notice it in the iPhone they gave me in exchange.
     
  6. troyyy, Jul 28, 2011
    Last edited: Jul 28, 2011

    troyyy thread starter macrumors newbie

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    Jul 28, 2011
    #6
    Did you browse the full-size image (640*960) without zoom in or out?

    If it doesnt flicker on your ip4,you dont have this issue.what's your ios version,4.3.x?

     
  7. IrishVixen macrumors 68020

    IrishVixen

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    Jun 20, 2010
    #7
    Not seeing it here FWIW--year old iPhone 4 running 4.2.1 (JB'd).
     
  8. Kyotoma macrumors 68000

    Kyotoma

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    Nov 11, 2010
    Location:
    Carnegie and Ontario
    #8
    I saved your attached image to Mobileme and viewed it via the Gallery App.

    I have a white iPhone 4 GSM running iOS 5.0 beta 4. I'm in the process of developing my first app actually =]
     
  9. troyyy thread starter macrumors newbie

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    Jul 28, 2011
    #9
    The image is using for test screen glitches.I hope it's a software issue and ios5 solve it :)

    So you are a deveoper,good luck for you!
     
  10. troyyy thread starter macrumors newbie

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    Jul 28, 2011
    #10
    The image is using for test screen glitches.I hope it's a software issue and ios5 solve it :)

    So you are a deveoper,good luck for you
     
  11. psonice macrumors 6502a

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    Jul 22, 2005
    #11
    I guess not everyone can see this even if their phone has it. Basically, with that picture showing full screen and *not* zoomed it, it should just look grey from a distance, or very thin horizontal lines if you look close. What I see is a *very slight* flickering with this image, like the screen is flashing on and off very fast (so fast that it's only just noticeable).

    I'd say in practice it's never going to have any practical impact whatsoever, unless you like looking at test images like this. The effect is very slight, even with the test image, and I can't see it anywhere else.

    A quick explanation so people understand what this 'interlacing' effect is:

    Normally with a screen, you draw every line of pixels on the screen when you update it. When it's interlaced, you draw just half of them - first the odd lines, then the next time it updates you draw the even lines.

    This way you only have to draw half of the screen instead of all of it, which can save power and get the hardware running faster. The downside is that because it's only drawing each line every 2nd update the line effectively flashes on and off - causing it to flicker. Say you draw a white line, on the first update you draw it and it's white, on the second update you don't so it switches to black. It ends up flashing on and off like a strobe light!

    Screens (especially LCDs) are slow to update though, so in practice it doesn't flash back to black, it just fades to slightly grey before going back to white. That makes the flicker very hard to see. And if you draw an area of white instead of just one line, the lines blend together in your vision and the flicker pretty much disappears. This is why you don't see it when you're using the iPhone normally, but it's visible with the test image made of white and black lines.

    One thing I don't get though: interlace is well known on old CRT TVs, but I thought it wasn't used at all with LCD? And isn't LCD supposed to stay at the current colour if it's not updated?
     
  12. troyyy thread starter macrumors newbie

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    Jul 28, 2011
    #12
    The top and bottom bar flickering is more obvious
     

    Attached Files:

  13. psonice macrumors 6502a

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    Jul 22, 2005
    #13
    troyy: the top + bottom bars are much less obvious to me. The image alone clearly flickers, but I can't see any flicker in the bars.
     
  14. troyyy thread starter macrumors newbie

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    Jul 28, 2011
    #14
    What bother me is my iphone4 screen seems not sharp enough as a "retina display",I can see the horizontal pixel If looking very carefully:(
     
  15. msb3079 macrumors 6502a

    msb3079

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    collingswood. nj
    #15
    I went through 4 replacement iPhone 4's. Most had different screen issues. Extreme yellow, dead pixels, then this issue. They finally sent me a BRAND NEW in a box iPhone 4. It is not as cool (color temp) as I would like but it does not have this issue, so I'm happy with it.

    Definitely not normal though. The genius claimed to not be able to see it. But so did friends. I used to calibrate home theater... maybe that's why I could see it so easy? But once I noticed it, it bothered me daily.
     
  16. Fuchal macrumors 68020

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    Sep 30, 2003
    #16
    Most if not all iPhones sold in the past 6 months thru today have this issue to some degree. I was unable to get a replacement from Apple that didn't have this issue. I've learned to live with it. My launch day iPhone 4 did not have this problem. I think some people are just more sensitive to the refresh rate of the display than others.
     
  17. troyyy, Jul 28, 2011
    Last edited: Jul 28, 2011

    troyyy thread starter macrumors newbie

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    Jul 28, 2011
    #17
    yep,once noticed,bothered always. I exchanged my 10 months ip4 because homebuton issues,and then found this screen issues in the new one.Apple increased in production and lead to a decline in the quality. I know if I go to the apple store and show the genius the test image,they will give me a replacement,but I'm worried there would be more issues,as dead pixels,extreme yellow,battery...

    I hope it is a software problem,cause after using for a while and warms up,the flickering seems go away.
     
  18. troyyy thread starter macrumors newbie

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    Jul 28, 2011
    #18
    maybe you are right,but I didnt notice this in my old iphone,I notice this issue soon after getting the exchange one
     
  19. msb3079 macrumors 6502a

    msb3079

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    Apr 20, 2010
    Location:
    collingswood. nj
    #19
    No, not right. It's definitely an issue. Some people don't have good enough eye site or care enough to see it, I guess. Some people can't even tell the difference between a "warm" or "cool" screen.
     
  20. WeegieMac Guest

    WeegieMac

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    Jan 29, 2008
    Location:
    Glasgow, UK
    #20
    The interlace lines sometimes catch my eye when I quickly shift the focus of my eyes from one part of the screen to another, but just sitting looking at the screen itself, I can't see anything.
     
  21. JCCL macrumors 6502a

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    Apr 3, 2010
    #21
    Good found, very noticeable on my iPhone 4......running iOS 5 Beta 4.
     
  22. Merkie macrumors 68020

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    Oct 23, 2008
    #22
    This is the primary reason I'm still running iOS 4.2.1.
     
  23. troyyy thread starter macrumors newbie

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    Jul 28, 2011
    #23
    I see some guys say it is ios4.3.X issue,so it that true?

    I suspect a relationship with production batches,the screens from different batches need different refresh rate,maybe very small difference,but apple doesn't take it into account
     
  24. iMattcotv macrumors 6502

    iMattcotv

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    Jun 22, 2010
    #24
    I see the flickering as well.

    Viewing this picture really gives you an idea of how close the pixels are together though xD

    The thing looks frikkin grey!!
     
  25. Merkie macrumors 68020

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    Oct 23, 2008
    #25
    It does occur sometime, but it's significantly less than on iOS 4.3.x. The occurance in iOS 4.3.x and higher is about 10 times higher I think.
     

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