LCD panel type The quality of an LCD depends first on its panel, because the quality of the panel directly affects the viewing effect of the picture, and the LCD panel accounts for more than half of the cost of the whole machine, which is the main factor affecting the cost of LCD TV. Therefore, to choose a good LCD, we must first choose its panel. LCD panel can largely determine the brightness, contrast, color, viewing angle and other very important parameters of LCD. LCD panels are developing rapidly, from three generations in previous years to four or five generations, and then skipping six generations to seven generations, and a newer eighth generation panel is also being planned. At present, the manufacturers of LCD panels are mainly Samsung, LG-Philips, AUO, etc. Due to the differences of various technical levels, the LCD panels produced are roughly divided into different types. Common ones are TN panel, VA panel such as MVA and PVA, and IPS panel.

       TN is called Twisted Nematic (twisted nematic) panel, and its low production cost makes TN the most widely used entry-level LCD panel, which is widely used in the mainstream low-end LCD on the market at present. At present, most of the TN panels we see are improved TN+film, which is the compensation film, which is used to make up for the deficiency of the viewing angle of TN panels. At present, the viewing angle of improved TN panels reaches 160, which is of course the limit value measured by the manufacturer when the contrast ratio is 10∶1. In fact, when the contrast ratio drops to 100 ∶ 1, the image is distorted or even color cast.
　　As a panel of 6Bit, TN panel can only display 64 colors of red, green and blue, and the maximum actual color is only 262.144. Through "dithering" technology, it can obtain the performance ability of more than 16 million colors, and can only display the three primary colors of 0 to 252 gray scales. Therefore, the final color display number information is 16.2 M, instead of the true color 16.7M as we usually say; In addition, it is difficult to improve the contrast of TN panel, and the directly exposed problems are thin color, poor restoring ability and unnatural transition.

　　 The advantages of TN panel are that due to less gray scale output, fast deflection speed of liquid crystal molecules and easy improvement of response time, TN panel is basically used for liquid crystal products below 8ms in the market at present. In addition, Samsung has also developed a B-TN(Best-TN) panel, which is actually an improved type of TN panel, mainly to balance the contradiction that high-speed response of TN panel must sacrifice image quality. At the same time, the contrast ratio can reach 700∶1, which is close to the panel of MVA or early PVA. Many panel manufacturers in Taiwan Province produce TN panels. TN panels are soft screens, and similar water lines will appear when you gently stroke them with your hands. In addition, a closer look at the screen is roughly like this:

       VA panel is a panel type with more high-end LCD applications, and it belongs to wide viewing angle panel. Compared with TN panel, 8-8bit panel can provide 16.7M color and large viewing angle, which is the capital of high-end positioning of this kind of panel, but the price is also more expensive than TN panel. VA panels can be divided into MVA panels dominated by Fujitsu and PVA panels developed by Samsung, of which the latter is the inheritance and improvement of the former. The front (front) contrast of VA panel is the highest, but the uniformity of the screen is not good enough, and color drift often occurs. Sharp text is its killer, and the contrast between black and white is quite high.

　　Fujitsu's MVA (Multi-domain Vertical Alignment) technology can be said to be the earliest wide-angle LCD panel technology. This kind of panel can provide a larger viewing angle, usually up to 170. Through technical authorization, panel companies such as Chi Mei Electronics (Chi Jing Optoelectronics) and AUO Optoelectronics in Taiwan Province Province of China have adopted this panel technology. The viewing angle of the improved P-MVA panel can reach 178 close to the horizontal level, and the gray-scale response time can reach below 8 ms.
       Samsung Electronics' PVA(Patterned Vertical Alignment) technology also belongs to the category of VA technology, and it is the successor and developer of MVA technology. Its comprehensive quality has surpassed the latter in an all-round way, and the improved S-PVA can keep pace with P-MVA, obtaining a wide viewing angle and faster and faster response time. Using PVA transparent ITO electrode instead of the liquid crystal layer protrusions in MVA, the transparent electrode can obtain better aperture ratio and minimize the waste of backlight. This mode greatly reduces the possibility of "bright spots" on LCD panels, and its position in the era of LCD TV is equivalent to the "dragon tube" in the era of kinescope TV. Wide-angle technology of PVA mode promoted by Samsung is widely used by Japanese and American manufacturers because of its strong production capacity and stable quality control system. At present, PVA technology is widely used in high-end LCD or LCD TV. Class VA panel is also a soft screen, and similar water lines will appear when you gently stroke it with your hand. Look at the screen carefully.

      IPS(In-Plane Switching) technology is a liquid crystal panel technology introduced by Hitachi in 2001, commonly known as "Super TFT". The IPS camp is headed by Hitachi, which has gathered a number of manufacturers such as LG- Philips, Hanyu Caijing, IDTech (a joint venture between Chi Mei Electronics and IBM in Japan), but not many models can be seen in the market. The biggest feature of IPS panel is that its two poles are all on the same plane, unlike other liquid crystal mode electrodes, which are arranged in three dimensions on the upper and lower sides. Because the electrodes are on the same plane, the liquid crystal molecules are always parallel to the screen in any state, which will reduce the aperture ratio and light transmittance. Therefore, more backlights will be needed when IPS is applied to LCD TV. In addition, there is an S-IPS panel, which is an improvement of IPS.

       The advantages of IPS panel are high viewing angle, fast response speed, accurate color reproduction and low price. However, the disadvantage is that the light leakage problem is serious, and the purity of black is not enough, which is slightly worse than PVA. Therefore, it is necessary to rely on the compensation of optical film to achieve better black. At present, IPS panels are mainly produced by LG- Philips. Compared with other types of panels, the screen of IPS panel is "hard", and it is not easy for water patterns to deform when it is lightly scratched by hand, so it is also known as a hard screen. When you look at the screen carefully, if you see fish-scale pixels facing to the left, plus a hard screen, you can be sure that it is an IPS panel.

       CPA (Continuous Pinwheel Alignment) mode wide viewing angle technology (soft screen). Strictly speaking, CPA mode wide viewing angle technology also belongs to the VA camp, and each liquid crystal molecule is arranged in a fireworks-like manner toward the central electrode. Because the electric field on the pixel electrode changes continuously, this wide viewing angle mode is called "continuous fireworks arrangement" mode. CPA is promoted by Sharp, the "father of LCD". It should be noted here that ASV, which Sharp has always promoted, does not actually refer to a specific wide-angle technology. It collectively refers to the products that have adopted TN+Film, VA and CPA wide-angle technologies as ASV. In fact, only CPA mode is Sharp's own wide-angle technology, and its products are basically the same as MVA and PVA. That is to say, the LCD TV of Sharp brand is not necessarily the CPA mode LCD panel produced by Sharp itself, but the VA mode panel made by Taiwan Province manufacturer or the LCD panel made by other manufacturers may be used. Sharp's CPA panels are true in color reproduction, excellent in viewing angle, delicate in image and expensive, and Sharp rarely sells CPA panels to other manufacturers. CPA panel is also a soft screen, and a similar water pattern will appear when you gently stroke it with your hand. Look carefully.屏幕大致是这样的：

       In addition, some other manufacturers also have their own LCD panel technologies, such as NEC's ExtraView technology, Panasonic's OCB technology, modern FFS technology, etc. These technologies are all improvements to the old TFT panels, providing viewing angle and response time, and are usually only used on their own brand LCD monitors or LCD TVs. Actually, these panels are all TFT panels, but now various panels have their own technologies and names, so the name TFT is not often used.