LCD burn-in?

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tarom
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LCD burn-in?

Post by tarom » Tue Feb 13, 2018 9:06 am

I wonder if there is any bad effect of displaying same off image for a long time. According to Wikipedia, "screen burn-in" also exists for LCDs.
https://en.wikipedia.org/wiki/Screen_burn-in

grsbanks
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Re: LCD burn-in?

Post by grsbanks » Tue Feb 13, 2018 9:11 am

The LCD in the DM42 is comparatively new technology from Sharp called "Memory LCD".

https://www.sharpsma.com/products?sharp ... parallel=0

It's designed for this and actually uses up zero power to maintain the display when the calculator is switched off.
Not SwissMicros staff, just an enthusiast.

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Walter
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Re: LCD burn-in?

Post by Walter » Tue Feb 13, 2018 9:18 am

Quote from the Wikipedia page you pointed to:
Plasma displays were at one time highly susceptible to burn-in, while LCD-type displays are generally not affected. ...

In the case of LCDs, the mechanics of burn-in are different than plasma and OLED, which develop burn-in from luminance degradation of the light-emitting pixels. For LCDs, burn-in develops in some cases because pixels permanently lose their ability to return to their relaxed state after a continued static use profile. In most typical usage profiles, this image persistence in LCD is only transient.
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DM42 SN: 00041 --- Follower of Platon.

HP-35, HP-45, ..., HP-50, WP 34S, WP 31S, DM16L

reavy
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Re: LCD burn-in?

Post by reavy » Wed Feb 14, 2018 7:44 am

grsbanks wrote:
Tue Feb 13, 2018 9:11 am
The LCD in the DM42 is comparatively new technology from Sharp called "Memory LCD".

https://www.sharpsma.com/products?sharp ... parallel=0

It's designed for this and actually uses up zero power to maintain the display when the calculator is switched off.
So is this display technology similar to the e-Ink used in readers like the Kindle and Kobo? Certainly sounds like it. I would be interested to know if anyone knows about differences between e-Ink and this Sharp display tech.

grsbanks
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Re: LCD burn-in?

Post by grsbanks » Wed Feb 14, 2018 11:42 am

It's still an LCD and therefore a lot faster than eInk. eInk is a purely reflective technology while LCD technology is still based on varying transparency of pixels on screen.
Not SwissMicros staff, just an enthusiast.

Thomas Okken
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Re: LCD burn-in?

Post by Thomas Okken » Wed Feb 14, 2018 11:49 am

(Deleted by Poster because redundant.)
Last edited by Thomas Okken on Wed Feb 14, 2018 12:02 pm, edited 1 time in total.

dlachieze
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Re: LCD burn-in?

Post by dlachieze » Wed Feb 14, 2018 11:53 am

reavy wrote:
Wed Feb 14, 2018 7:44 am
I would be interested to know if anyone knows about differences between e-Ink and this Sharp display tech.
They are two different technologies, e-ink is based on microcapsules including two pigments (black and white) and by applying an external electrical field you move either pigment on the surface of the capsule, then it will stay there and the image is permanent without any need for power. (See: Electronic Ink)

The Sharp display is a LCD display using liquid crystals with a 1 bit data memory in each pixel (Sharp Memory LCD Technology), my understanding is that it still needs an ultra-low amount of power to maintain the image, so if the LCD power source is turned off as it is in the DM42 you may see the image fading away once all remaining power from capacitance is consumed. However it seems that this requires a very long time, more than a couple of weeks as mentioned in this post from Michael.
DM42 SN: 00425

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