One day you discover on your monitor an image that can´t be erased…
We regularly play the roll of the bearer of bad news concerning LCDs. Lately you have already seen:
All this is without recalling the recurrent problem of dead pixels.
If this wasn´t enough, here is something as interesting: the persistence of images on LCDs, which isn´t often covered by warranties.
We are not trying to shoot down LCD monitors to praise other alternatives, existing or future technologies. It’s more that with monitor tests, we progressively increase our knowledge in this domain and we sometime discover hidden defects.
Conclusion and show down
Everyone (except for manufacturers) agree on the basic principle. The phenomenon of image persistence appeared or became problematic when the panel manufacturers accentuated the overdrive to accelerate liquid crystals’ rotation. It happened two years ago, with the change from 16 ms to 12 ms LCDs. All have acknowledged this defect and to counter this problem they recommend turning off the monitor for a long period of time, or displaying various images and using screensavers.
We came across the problem and we advise you to follow their advice. Working with a previous image in the background is very annoying and you quickly tend to focus on it. We have warned you that only a few manufacturers make their warranty work if this problem arises.
We can hardly blame them as this default isn´t due to one unit in particular but to the principle of recent panels. If you start over the same procedure on the new unit and display for several consecutive days the same image without shutting down your monitor, you might have the same problem. So manufacturers should clearly indicate in their manuals instruction or even on the packaging (so you can´t miss it) that their monitors aren´t conceived to display fixed images for long periods of time and that you have to use screensavers to avoid any marking risks.
And then there is the discordant voice of Conrac, who builds public displays. They say to have discovered THE truth but don´t want to share the information. Too bad…
However, to put the danger in perspective, we displayed a fixed image on several TN, IPS, and VA monitors including the ViewSonic VX922 (probably the strongest overdrive) and after 48H without a screensaver, changing anything or switching off, the display remained impeccable. Do we have to wait longer for the components “settle in� If you have a doubt, activate the screensaver in case of prolonged non use. It will be best for your monitor, environment and electricity bill…
To finish, we would like to thank the manufacturers who, except for HP and Conrac, agreed to be transparent and give us straight answers.
For the complete article Click Here
We regularly play the roll of the bearer of bad news concerning LCDs. Lately you have already seen:
- -14% tax on DVI (only Europe)
- - absence of HDCP certification for almost all displays on the market;
- - Mura effect on panels and backlight spots
- - problems of color quality with time
- - flagrant lack of brightness homogeneity in big monitors
All this is without recalling the recurrent problem of dead pixels.
If this wasn´t enough, here is something as interesting: the persistence of images on LCDs, which isn´t often covered by warranties.
We are not trying to shoot down LCD monitors to praise other alternatives, existing or future technologies. It’s more that with monitor tests, we progressively increase our knowledge in this domain and we sometime discover hidden defects.
Conclusion and show down
Everyone (except for manufacturers) agree on the basic principle. The phenomenon of image persistence appeared or became problematic when the panel manufacturers accentuated the overdrive to accelerate liquid crystals’ rotation. It happened two years ago, with the change from 16 ms to 12 ms LCDs. All have acknowledged this defect and to counter this problem they recommend turning off the monitor for a long period of time, or displaying various images and using screensavers.
We came across the problem and we advise you to follow their advice. Working with a previous image in the background is very annoying and you quickly tend to focus on it. We have warned you that only a few manufacturers make their warranty work if this problem arises.
We can hardly blame them as this default isn´t due to one unit in particular but to the principle of recent panels. If you start over the same procedure on the new unit and display for several consecutive days the same image without shutting down your monitor, you might have the same problem. So manufacturers should clearly indicate in their manuals instruction or even on the packaging (so you can´t miss it) that their monitors aren´t conceived to display fixed images for long periods of time and that you have to use screensavers to avoid any marking risks.
And then there is the discordant voice of Conrac, who builds public displays. They say to have discovered THE truth but don´t want to share the information. Too bad…
However, to put the danger in perspective, we displayed a fixed image on several TN, IPS, and VA monitors including the ViewSonic VX922 (probably the strongest overdrive) and after 48H without a screensaver, changing anything or switching off, the display remained impeccable. Do we have to wait longer for the components “settle in� If you have a doubt, activate the screensaver in case of prolonged non use. It will be best for your monitor, environment and electricity bill…
To finish, we would like to thank the manufacturers who, except for HP and Conrac, agreed to be transparent and give us straight answers.
For the complete article Click Here