Electronic Paper

Electronic PaperDevelopment of various means of visual data display has gone through various processes. Developers have always wanted to design such device which would be as convenient and perceivable as a regular paper. And despite numerous efforts of modern technology such device was not achievable for a certain period of time. Electron-beam monitors were shimmering and emitting harmful radiation. Later versions of LCD monitors didn't have these disadvantages but still radiated light as they used matrix illumination. And this is very tiring for eyes during the process of reading.Finally a new technology was developed. It is called the electronic paper, or the electronic ink.The main idea was to make a device with a screen which did not radiate light where the image was formed in the reflected light. It had to be visible for us, just like an image on a regular paper.The main elements of the device are microcapsules. These are micro-size cells which contain a certain amount of two-colour particles of a pigment. White particles are charged positively while black particles are charged negatively. The rest of the space is filled with liquid. The whole screen is covered with a coordinate gird. The micro-granules are kind of squeezed between two electrodes - i.e. a transparent upper electrode and a non-transparent lower electrode. Thus an electric charge can be supplied to certain points. When this happens white particles of the point rise while black particles sink inside the granule and become invisible. By changing polarity we shall have black particles on the screen's exterior. The image is formed by them in a white background.It is important to note that particles remain in their places even when there is no electric power supply. Thus the electric paper has other advantages. The devices based on this technology consume little energy. They are very light and thin. Unlike in LCD technology their viewing angle is practically unlimited. The electronic paper can also be flexible.Most often this technology is used in making compact devices for reading electronic books which are called readers. Nowadays even some newspapers produce electronic versions for such devices. Besides, this technology can be used for data display in other devices such as mobile phones. It is also used in street advertisements and posters.The main disadvantage of the technology is its low matrix refresh rate or its long response time - about 250 milliseconds. So such displays cannot be used for a dynamic quickly-changing image, for example, for watching videos. The displays also do not have many shades of gray.However, such displays quite suffice for reading books as the electronic paper displays the next page at the same rate as we page a newspaper or a book.

Category:

Science & Technology

Tags:

• display
• display information
• handheld device
• technology