Is there a display refresh rate in E-INK Carta technology?

Question

Electronics

In computer monitors, basically, it is 60 GHz, in very modern and expensive computer monitors and TVs it is 120 GHz. Do e-books have a refresh rate?

Answer 1

There the principle is different - perhaps even the opposite.
It's not an update, it's an erasure. If necessary - when you need to change the picture.
You don't need to update. Electronic paper stores once placed on it even when the power is turned off.
Therefore, the refresh rate as such is not in principle.
Artyom Kotok ,
Flickering there at the time of redrawing.
Redrawing - depending on the needs of the application. For example, if you are reading a book, then when you turn the pages.
Moreover, flickering is even more unpleasant than that of conventional screens.
But if the image does not change, then there is absolutely no flicker, unlike conventional screens that flicker even if the picture is unchanged.
And that is why "electronic paper" is great for reading devices.
It is impossible to make an ordinary tablet based on it.
PS:
In addition to the absence of flicker when reading, electronic paper also has a huge energy savings.
Since electricity is spent only on flipping (well, on the backlight, of course).
As long as the image does not change, there are no energy costs for the screen itself.
Therefore, the battery lasts for a very long time.
Example:
A typical reader, even with regular use, lives for 1 month easily. From a single battery charge.
Readers based on Android are still more voracious, they last for a couple of weeks.
It's not related to the screen. And this is a common problem for both conventional screens and "electronic paper".
This is the so-called. the problem of high-quality or low-quality implementation of PWM in the backlight.
The fact is that backlight LEDs are not so easy to make dimmer if you do not need backlighting at full power.
A solution was invented - the current is not constantly supplied to the backlight LEDs.
And "on-off-on-off-on-off-..."
When it is necessary to reduce the brightness, the periods of "off" are lengthened, the periods of "on" are shortened.
This "on-off-on-off-..." is done very quickly. So the human eye would not have to see it , but would have to perceive the glow of the backlight LEDs as constant.
But if poor-quality implementation of the backlight - it still flickers.
PS:
"Electronic paper" does not need a backlight if you do not read at night / in semi-darkness.
So you can do without backlighting at all, which will guarantee the absence of flicker.
This is a common problem with any type of LED lighting and any backlight of any screen where there is an adjustment in this way through "on-off-on-off ...".
That is, it does not depend on the type of screen, but on the quality of a particular implementation of the backlight in a particular case.

Answer 2

The idea of ​​E-INK is not to stupidly redraw an image just for the sake of the fact of redrawing. So, the image on the screen is updated only at the time of its actual update: turning the page, entering text, etc.

Answer 3

There is no refresh rate in e-paper readers because the image only updates when it changes. Electronic paper has a different parameter - the refresh time, that is, how long the picture can be completely changed to another. It doesn't happen as fast as it does on monitors with other technologies, but that doesn't matter.