Views: 202 Author: Reshine Display Publish Time: 2023-07-28 Origin: Site
The global flat panel display market is currently dominated by TFT (Thin Film Transistor) LCDs. Due to its low price, clear colors, acceptable view angles, low power consumption, manufacturing-friendly design, slim physical structure, etc., it has forced CRT (Cathode-Ray Tube) VFD (Vacuum Fluorescent Display) displays off the market and limited LED (Light Emitting Diode) displays to only large size display areas. TFT LCDs are widely used in TVs, computer monitors, medical equipment, household appliances, cars, kiosks, point-of-sale (POS) terminals, low-end mobile phones, industrial meters, smart homes, handheld devices, video game systems, projectors, consumer electronics, and advertisements, among other things. Visit our knowledge base for more details on TFT displays.
TFT LCD refers to an LCD that uses TFT technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, as opposed to a passive matrix LCD or a simple, direct-driven LCD with a few segments and no TFT in each pixel.
TFT LCD Technology comes in a variety of forms. Different TFT LCD technologies have distinct characteristics and applications.
One of the oldest and least expensive types of LCD technology is the TN-type TFT LCD. Although TN TFT LCDs have fast response times, their main advantages are poor color reproduction and narrow viewing angles. Colors will change depending on the viewing angle. To make matters worse, it has a viewing angle that causes grayscale inversion. Scientists and engineers worked hard to solve the major genetic issues. TN displays can now look significantly better than older TN displays from decades ago, but TN TFT LCD has inferior viewing angles and color compared to other TFT LCD technologies.
Hitachi Ltd. developed the IPS (In-plane switching) Type IPS TFT LCD in 1996 to improve the poor viewing angle and color reproduction of TN panels. Its name is derived from the difference in in-cell twist/switch between TN LCD panels. Instead of moving perpendicular to the panel plane, the liquid crystal molecules move parallel to it. This modification reduces the amount of light scattering in the matrix, which gives IPS its distinctive wide viewing angle and color reproduction. However, when compared to TN-type TFT displays, IPS TFT displays have a lower panel transmission rate and higher production cost, but these flaws do not prevent them from being used in high-end display applications that require superior color, contrast, viewing angle, and crisp images.
Fujitsu invented MVA (Multi-Domain Vertical Alignment) technology. The mono-domain VA technology is widely used in monochrome LCDs to provide a pure black background and improved contrast; the uniform alignment of the liquid crystal molecules causes the brightness to change with the viewing angle.
MVA solves this problem by causing the liquid crystal molecules on a single pixel to have multiple directions. This is accomplished by dividing the pixel into two or four domains and tilting the liquid crystal molecules in different directions using protrusions on the glass surfaces. The brightness of the LCD can thus be made to appear uniform across a wide range of viewing angles.
MVA is still used in some applications, but it is being phased out in favor of IPS TFT LCD displays.
Boe-Hydis of Korea developed this LCD technology based on IPS. Known until 2003 as fringe field switching (FFS), advanced fringe field switching is a technology similar to IPS that offers superior performance and color gamut with high luminosity. Light leakage causes color shift and deviation, which is corrected by optimizing the white gamut, which also improves white/grey reproduction. Hydis Technologies Co., Ltd., Korea (formerly Hyundai Electronics, LCD Task Force) created AFFS.
Hydis Technologies Co., Ltd licensed its AFFS patent to Hitachi Displays of Japan in 2004. AFFS is used by Hitachi to manufacture high-end panels in their product line. Hydis also licensed its AFFS to Sanyo Epson Imaging Devices Corporation in 2006. (Reference)
In concept, the AFFS is similar to the IPS; both align the crystal molecules parallel to the substrate, improving viewing angles. The AFFS, on the other hand, is more advanced and can better optimize power consumption. The most notable feature of AFFS is its high transmittance, which means that less light energy is absorbed within the liquid crystal layer and more is transmitted toward the surface. Because IPS TFT LCDs typically have lower transmittances, a brighter backlight is required. This difference in transmittance is due to the AFFS's compact, maximized active cell space beneath each pixel.
AFFS is used in high-end LCD applications such as high-end cells. phone due to its excellent contrast, brightness, and color stability.
