E-paper displays achieve visual effects by reflecting ambient light, so they look more like regular paper. This type of display is very energy efficient, because once the display is turned on, it no longer needs current to maintain the display of text, and only consumes energy when turning pages.
Cholesterol liquid crystals use materials that are similar in structure to cholesterol molecules, hence the name. In addition to pure cholesteric liquid crystals, there are also nematic liquid crystals added with optical rotators, or nematic liquid crystals added with cholesteric liquid crystal molecules. The liquid crystals added with materials have different wavelengths and optoelectronic properties. Nematic liquid crystal after adding the optical active agent, the liquid crystal material will produce a helical structure. Placing cholesteric liquid crystals on two horizontal substrates, in the absence of electric field alignment, the cholesteric liquid crystals tend to be arranged in a plane helical arrangement, and can reflect light with colors under the condition of reflection conforming to a specific light wavelength, or is in a transparent state. Cholesteric liquid crystals can achieve a bistable effect in two ways: one is Surface Stabilized Cholesteric Texture (SSCT); the other is polymer stabilized cholesteric Texture (PSCT), both of which are One of the very popular cholesteric liquid crystal display technologies.
The working principle of cholesteric liquid crystal display is: on the component, it includes upper and lower substrates, spacers and black absorbing materials like general passively driven liquid crystals. The upper and lower substrates can be made of glass or plastic substrates, except for passive driving electrodes and alignment layers In addition, in order to achieve a good reflection effect, the size of the spacer is about 6-8 times of the pitch.
Electrophoresis has several advantages. One is low energy consumption. Thanks to the bistability, the image remains on the display for days or months after the power is turned off. Second, the displays produced by electrophoretic technology are reflective, so they have good sunlight readability, and can also be combined with front or side light for use in dark environments. The third is the potential for low production costs, as the technology does not require strict packaging and is feasible with solution processing techniques such as printing. Fourth, electrophoretic displays feature flexible form factors, allowing them to be fabricated on plastic, metal or glass surfaces, so it is the best choice for flexible display technology.
The thickness of E-ink display devices is usually very small, the weight is also quite light, but the structure is more durable than ordinary LCD. Can these advantages make it not favored by those portable device manufacturers? Traditional LCD devices are limited in terms of structure. Its thickness cannot be too thin (if the thickness of the two layers of glass of the LCD screen is 0.7mm, and the thickness of the two layers of substrates is 0.5mm thick, then the thickness of the LCD screen will not be less than 2mm), The weight can't be too light either. The hardware structure of the electronic ink display device is quite simple, its thickness can be about 1mm, and the thickness of the display screen is less than half of that of the LCD. In addition, e-ink has a wide range of applications. It can be used not only on glass surfaces, but also on surfaces such as plastics, so it will not be as fragile as LCD displays. A comparison of thicknesses of TFT LCD displays, first-generation e-ink displays, and future e-ink displays is shown.
Low power consumption
The power consumption of e-ink is quite low, and it can display a picture even when the power supply is briefly stopped. The reason for its very low power consumption is that its reflectivity and contrast are very high, and there is no need for backlighting to improve readability.
To sum up, the display device using e-ink technology will have the same visual characteristics as paper media, but also have the advantages of low power consumption, thin thickness and light weight, making it a new favorite of portable devices, especially for those who require These are applications where transmissive LCDs and reflective LCDs cannot meet the requirements of better display effects under all kinds of light.
The electronic ink display device can follow the production equipment of AMLCD, and the production process is simpler. Just apply the electronic ink to the IT0 plastic substrate, and then use the Laminator process to attach it to the TFT backplane. This process is the same as the polarizing film attachment method in the LCD production process, and this process can be used Existing equipment or similar equipment for production. The simplification of the production process means higher yields and higher yields, coupled with a reduction in substrate thickness, which results in significant cost reductions (still more expensive than paper, of course).