What is the use of such a retro screen with only black and white images?

Huawei will soon be marketed a tablet these days is quite eye-catching, because its screen is only black and white, I guess many partners have no concept of black and white display, right? Into the color display for decades, why use the black and white screen again? This screen is called electronic ink and what is it? How today to talk about it.


Electronic ink (E Ink) is very different from LCDs in that each cell is filled with liquid and contains two kinds of small black and white particles with different charges, and the upper and lower surfaces of the pixel dots are electrodes. When the upper surface electrode is positive, the white particles will be attracted to “swim” to the upper surface, while the black particles will swim to the lower surface, and the pixel will look white from the outside (above). The upper and lower surface electrodes are also subdivided into multiple or support multiple voltages to achieve the effect of mixing black and white particles, i.e., different shades of gray.


Because no matter what state the black and white particles are, they completely block the upper and lower surfaces, so they are not light-transmitting, and of course, you can’t use the backlight. It is really the same as paper, depending on external light to watch the surface of the black and white color, which is why many of these screen devices will be equipped with reading lights. By the way, liquid crystal display is by changing the liquid crystal arrangement to different degrees of light transmission to show different brightness / color.


The biggest benefit of electronic ink is that it is particularly power efficient. Since the interior is a liquid with some resistance to movement, the particle distribution can be maintained on its own for a longer period of time after it has been determined, and during this time the electrodes can actually be unenergized or kept in a very weak current to maintain the particle state. Black and white ink screen only need black and white, so a cell is a pixel, compared with LCD with three or more solid color cells combined with a pixel, but also much more delicate. Of course the omission of the backlight layer also reduces costs and thickness.


However, its disadvantage is obvious, because the internal liquid has a resistance to movement, so the black and white particles are slow to change state, and there are obvious residual images, so it is impossible to see the fast moving images. Although the black and white particles into red, green and blue, or simply red, green and blue three cells to form a pixel can also display color, but compared to the liquid crystal twist and the amount of light transmission adjustment, control the color particles with electrodes is not so fine, color display effect is not very good, so rarely used.


All said and done, is it practical to have a flat panel with only a black and white display? I think it is practical for some people. For example, the display speed requirements are not high text reading, electronic ink is more comfortable, look long is not easy to fatigue, but also special power saving; and want to write and draw, the surface of the ink screen can also be made more like paper than a smooth LCD screen, smooth to use. But the need to watch online video and play games partners, it really should not be considered.


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