words about lcd display
The liquid crystal display industry is a very special industry with a lot of new technologies and nouns, here will continue to collect knowledge about liquid crystal displays
Liquid Crystal (Liquid Crystal) is a polymer material in a state of matter between liquid and crystalline. There are many types of LCDs. There are thousands of commonly used liquid crystal display materials, mainly biphenyl liquid crystals, phenyl cyclohexane liquid crystals and ester liquid crystals. Liquid crystals can be divided into positive liquid crystals and negative liquid crystals. Generally, positive liquid crystals are used, and negative liquid crystals can increase the transmittance of the display screen, but the price is higher. MERCK of Germany owns the patent of negative liquid crystal, and Merck is also an excellent liquid crystal supplier in the industry, and JNC and DIC are also world-famous liquid crystal suppliers.
the clearing point of LCD
Liquid crystals can exhibit three types at different temperatures: liquid state, liquid crystal state and crystalline state. The temperature at which the liquid crystal state transitions to the liquid state is called the clearing point. When the temperature exceeds the clearing point, the liquid crystal turns into a liquid, so the display cannot work. The liquid crystal state temperature of the liquid crystal used in the liquid crystal display is usually between -30°C and 90°C.
what is LCD
LCD is the abbreviation of liquid crystal display. The basic structure of LCD is to inject liquid crystal into two glass substrates in a vacuum environment. TFT (thin film transistor) is made on one substrate glass, and color filters are made on the other substrate glass. Through control the signal and voltage on the TFT are changed to control the opening and closing of each pixel. LCD has excellent performance, thin and light appearance, and higher resolution. LCD monitors have completely replaced the CRT monitor market.
TN display mode
TN is the abbreviation of Twisted Nematic. Both the color filter and the TFT substrate are made with circuits. When the upper and lower substrates are energized, a vertical electric field is formed. This vertical electric field is used to control the rotation of liquid crystal molecules, thereby controlling whether the light passes through or not. setting screen. The TN display mode is normally white mode, that is, it is white when it is not working. The structure of the TN display mode is simple, and the response speed is fast. However, due to the arrangement of the liquid crystal molecules, the viewing angle of the TN display screen is relatively small. Moreover, when the display screen is pressed by external force, the display is abnormal due to the destruction of the arrangement state of the liquid crystal molecules, which is what we often call “soft screen”.
dot matrix LCD screen
Dot-matrix LCD screen is a display screen with a simple structure. This display screen does not have a color filter, so it can only display black and white colors. Commonly used backlight colors are yellow, green, and blue. Text or graphics can be displayed by controlling these points, and scrolling up, down, left, and right on the screen and animation functions can be realized. A common 12864 dot matrix LCD screen has 64 pixels vertically and 128 pixels horizontally.
VA display mode
VA is the abbreviation of vertical alignment, and VA is a kind of TN display mode. It can be subdivided into MVA (multi-domain vertical alignment) and PVA (patterned vertical alignment), both of which use materials to change the alignment state of liquid crystal molecules. Some use transparent resin, and some use transparent ITO electrodes. The VA display mode is normally black mode, that is, it is black when it is not working. This makes it possible to retain the advantages of a fast refresh rate in the TN display mode and improve the viewing angle.
IPS display mode
IPS is the abbreviation of In-Plane Switching. All the driving circuits are on the side of the TFT substrate, which has the characteristics of fast response speed and large viewing angle. The IPS display is normally black mode, that is, it is black when it is not working. This display mode is widely used in various display products, such as watches, mobile phones, tablets, display monitors, etc. When the display is pressed by external force, even if the liquid crystal molecules on the upper layer slide, the liquid crystal molecules will remain unchanged next time, so the screen will not change, that is, the hard screen that everyone often calls, so only IPS displays can be fully bonded.
ADS display mode
ADS is the abbreviation of Advanced Super Dimension Switch, which is improved on the basis of IPS display mode, and the patent belongs to BOE Technology Group Co., Ltd. This technology can improve the transmittance of the display screen and reduce light leakage.
FFS display mode
FFS is the abbreviation of Fringe Field Switching. It is improved on the basis of IPS display mode. This technology can improve the transmittance of the display screen and reduce light leakage.