Turning the tables, the electronic ink screen updated from only black and white to rich colors

“Do you know what color Naruto's hair is?” She asked suddenly.

What color the hell is the hair? All of a sudden, he asked himself. The Japanese comic had been finished years ago, but why can't he remember the color of the protagonist's hair?

He scratched his hair and suddenly remembered that he used to watch the comic with black-and-white e-books. How could he know the color of his hair?

"Red?" He asked cautiously.
She shook her head in disdain.

"What color is that?"
He had to ask her, that is a little embarrassing, who let him boast of being a Japanese comic expert and despise her every day?

It's yellow! She raised her ebook at him and showed a close-up.

“Wow! What is this?”
He didn’t care about the color of the hair. Oh no, he only cared about the color.

“What the hell! You got a color screen?” He grabbed the reader from her. It was very light. The appearance of it was right. It was definitely an e-ink screen, just like the King dow.

But it showed color! He opened his mouth in surprise and looked at her, who was standing there with disdain.

Why were the previous e-ink screens only black and white?

The display principle of a traditional black-and-white electronic ink screen is actually very simple. White or black is painted on the surface of the very small balls. And these little balls are put in small containers of which the diameter is smaller than the diameter of hair. The small containers are full of liquid, so these black and white balls are floating in the liquid. And the whole screen is made up of these small containers.

Because the white ball and the black ball have different charges, the movement of the black and white balls in the small container can be controlled by changing the external electric field. When all the black balls run to the display side, the place will be black, otherwise it will be white. The black and white combination of many small containers becomes the texts or images on the screen.

This is the application of the principle of electrophoresis to control the display of small particles. Because this effect has the characteristics of bistability, so the image shown does not tremble like the way happed in an ordinary liquid crystal screen. That makes the screen very friendly to the eyes.

One of the ways to turn black and white into color: add a color cover film

The traditional e-ink screen can only display black and white content because it has only black and white balls, and the gray level is displayed through black and white intermingle. Of course, you can't display colors with such screens.

What should I do if I have to show the color? One way is to overlay a color transparent film on the black-and-white screen, which is divided into many tiny areas. Each area is divided into three colors. Of course, this refers to three primary colors. In this way, small particles or pixels on the black-and-white screen control the brightness of these color parts, so as to combine them into different colors.

With such a method of implementing showing color, the brightness would be definitely worse than the original one because an extra film is attached. At the same time, three pixels on the black-and-white screen need to work together to control the three color parts of a single pixel on the color film. The color pixels are relatively bigger, that is, the display accuracy is reduced.

A better way to turn black and white into color

The color scheme described above will lead to the problems of light darkening and number of pixels reduction. If the original black-and-white display points are directly changed into color, there will be no need to use another layer of color film on the screen, so as to avoid the above problems.

The method is very direct, and changes the black and white particles into color particles. But this brings in new challenges. The accuracy requirements are greatly increased when more than two kinds of particles are involved, which put forward higher requirements for the control circuit and particles and containers.

That's why higher quality e-ink color screens are expensive and have only recently matured. Now, there are mature products of this kind, and they are gradually used by e-reader manufacturers to make products. However, I believe that because of the high price, the process of popularization will take a long time.

What can be lost when black and white becomes colors

In fact, pure black and white used to be a proud feature of traditional e-book readers. In addition to nostalgic factors, this monotonous tone blocks the information that interferes with reading, thus bringing users a focused reading experience in this impetuous video era. This is an admirable feature for deep text content readers.

Nowadays, the traditional black-and-white electronic ink screens have been developed into color electronic ink screens. Will this cause adverse effects instead? I believe that different users have different views. Some prefer to keep the original black and white, some are happy because of colors, and new users will be attracted to the e-reader market because of colors of the screen.