LCD 19 inches monitor always blurred

vbimport

#1

Hi all,

A friend recently bought a 19 inches very cool LCD monitor (IO DATA), but he cannot get crisp pixels (I have the same model as his in 17 inches and mine is displaying a much crisper image).

  • Resolution is set to 1280x1024.
  • I try changing the settings (clock, phase) but could not improve things.
  • Using the “auto” setup button did not fix this either.

Any idea apart bringing the screen back to the shop ? :confused:

Thanks a lot
k


#2

maybe you could try degassing the monitor . Have you installed the proper driver in windows for that LCD monitor ?


#3

cant degauss an lcd monitor. Degaussing is to reallign the magnetic field on a CRT. An lcd has no such field.

If an lcd does NOT run at its native resolution it will always look a little bit blurry. You said you hae it at 1280x1024? Try higher. try 1600x1200 and see if it stops being blurry.

Also lcd’s have a small “reaction time” effect which can lead to blurryness on fast motion (you can see it very evident on old laptops but it got alot better on recent ones)


#4

I did not know that degauss function is unavailable in LCD monitors .

My laptop does not show any blurness whereas my brother`s old celeron laptop does a lot while playing games or even while watching movies .


#5

Thanks, but it seems to be something else. :frowning:
Answers:

  • Yes, he installed the proper drivers.
  • No, the maximum resolution on his screen (like on most 19", I guess) is 1280x1024 (1600x1200 is not available).
  • No relation with the “reaction time”; even static images (texts) are blurred.

Do you think it could be caused by the graphic card?

  • I don’t think so since the “auto” button of the monitor is supposed to adjust to the signal given by the graphic card.
  • on the other hand, when the monitor shows its built-in menu, the menu itself is displayed perfectly, not blurred.

#6

What is the screen refresh rate set at? The proper refresh rate for ALL LCD monitor should be 60 Hertz, but some people set it higher thinking they’re running CRT… The default resolution for 19" LCD should be 1280x1024, but 1280x960 is fine too. BTW, which graphic is your friend running? Is he using the VGA or DVI connector for the monitor? Try changing the cable, could be bad cable. And last, turn off ClearType (Appearance>Effects). Wrong resolution + ClearType causes blur.


#7

Thanks, Stoner! :slight_smile:

  • I will tell him to check the cable. He was using the VGA connector. He bought a new graphic adapted today and used the digital output; not so surprisingly, display is crisp now.
  • He was using ClearType and I told him to remove it, but it did not fix it (I need to check that back with him, though); Anyway, I think not only the fonts but also any type of pixel was blurred.

Now, two points in your answer that got me puzzled:
1- His refresh rate was 60 Hz, but I told him to change to the maximum (75Hz - this did not change anything to his problem, BTW). On my monitor (17"), I feel that the display is much less tiring for my eyes in 75Hz than in 60Hz. In 60Hz, it’s like I can feel things are “flashing” very fast. Maybe just my imagination… but I have a fine result with 75Hz, so I am surprised by your answer. Why would they allow a higher refresh rate if this does not improve anything??? :eek:

2- Your suggestion of 1280x960 is very good. I should have mentionned a detail earlier: the pixels are blurred “horizontaly only”, I mean horizontal lines display fine (except their extremities which are blured to the right and left), and vertical lines are blurred all the way. So it seems, (am I right?) that the vertical setting (1024) is equal to the native resolution of the screen, while the horizontal setting (1280) could be the problem. Though, as I said, we already tried different resolutions without success (maybe the ClearType was still on at that time, I am not sure anymore).
Oops, I just tried on mine, and while I am fine in 1280x1024, my screen cannot show anything neat in 1280x768, even after pressing the “Auto” button, and both horizontally and vertically (so my previous theory seems totally wrong).
It seems it will stay a mystery. :rolleyes:

Since I don’t think my friend will spend more time in testing now that he spent the money for a new adapter, I guess you cannot help me more. Thanks a lot anyway :bow:. I hope this thread can be useful for someone who bumps into same problem… (good luck to them!)


#8

Hi - Blurry LCD screens is almosy always eith not using the correct resolution - which should be the highest you can select in control panel - or the auto adjustment not getting it ‘right’ - The monitor needs to see vertical lines and edges to auto adjust properly, and the best option is a test pattern designed to do the job.

Take a look at http://www.tft-lcd-monitor.co.uk/test-software.htm for a free program to do just this - it helps a LOT,

Regards,

the-hw-guy


#9

LCD’s dont have a refresh rate as such. They display a point on the screen continuously until that point is changed. Therefore 60, 75 or 10000Hz will look the same no matter what. When using a VGA connector though a 75Hz refresh will update the changes quicker but does not change the screen display at all, using a higher refresh rate though needs more signal bandwidth and on poor quality cables this can result in a blurred image. LCD’s should never flicker.

On a CRT each dot is drawn one after the other by a scanning beam, this leads to the flicker and is why a refresh rate on them is important. The dot on the screen is only displayed when the beam passes it.

It sounds like the blurring you were seeing is down to a poor VGA cable and graphics card. A VGA cable is not the best way to drive an LCD monitor as you are going from a digital image in the graphics card to analog over the cable and then back to digital in the LCD pannel.