After experiencing rapid development in 2005, LCD technology entered a new field. Response time, contrast, brightness, viewing angle... have all reached a new level, but there is also a very obvious problem in front of us, that is, in the face of many high-parameter LCD products, how can we get from What is the performance of the LCD monitor?
Undoubtedly, "wide viewing angle technology" is the most direct judgment method, because wide viewing angle technology is one of the new generation technologies promoted by major liquid crystal manufacturers, it not only relates to the viewing angle of Liquid Crystal Display, but also directly affects the liquid crystal display. Other performance parameters such as response time, brightness, etc. At present, there are four types of wide viewing angle technologies that are widely used by major LCD brands: TN+Film (TN+ viewing angle extension film) wide viewing angle technology, Fujitsu's MVA technology, Hitachi's IPS technology, and Samsung's PVA technology. Although these techniques are mainly based on improving the viewing angle, the reduction of response time, the expression of color, and the improvement of contrast are also included in these technologies.
Before we get a detailed understanding of these wide viewing angle technologies, we first need to understand the definition of viewing angles for liquid crystal displays. LCD is different from CRT. Because of its natural physical characteristics, when the user looks at different angles, the displayed image will be distorted. We change the picture quality to an unacceptable critical angle called its angle of view. The distortion of the picture mainly includes contrast, chromatic aberration and grayscale inversion (meaning that the low gray level is brighter than the high gray level).
TN+Film (viewing angle expansion film) wide viewing angle technology
TN+Film wide viewing angle technology is currently the most widely used in the low-end LCD market. Because it is based on the traditional TN mode liquid crystal, it only adds a film process to the original LCD panel. Since there are not many technical updates, the original production line is still used, which will not lead to a decline in the yield of liquid crystal products, and the cost is also controlled, so the price is lower, which is also an important reason why it can be sold in the low-end market. .
So why is this technology only applicable to low-end LCDs? The first is that the issue of highlights has not improved in this technology. In addition, the TN mode liquid crystal itself has a long response time, a small number of color elements, and a low aperture ratio, which is not improved in this technique. Therefore, this technology only improves the viewing angle, and it is obviously not used by the high-end LCD market. Its low cost and less than ideal performance determine that it can only be in the low-end market.
Although TN+Film (viewing angle expansion film) wide viewing angle technology has many shortcomings, it is not a very backward technology. Due to its mature technology, it only needs to adopt higher precision driving and optimization technology to overcome its inherent shortcomings. For example, the response time and the maximum number of color reductions can be superior to other new wide viewing angle technologies. Of course, the cost of the optimized TN+Film liquid crystal display is relatively increased, so the price must be slightly higher.
At present, most liquid crystal manufacturers have TN mode liquid crystal products, and only a viewing angle expansion film can be attached to obtain a wider viewing angle. However, it is worth noting that the low-end TN mode liquid crystal products have a wide viewing angle, but are easy to produce bright spots. The method of judging whether it is the TN mode is to observe the color change of the liquid crystal on the side of the display. If the bright place of the screen is darker on the side and the dark place is brighter, it means the TN panel.
High resolution
In order to realize a large-area high-resolution liquid crystal display, it is usually necessary to use low-impedance metal materials, high-performance switching elements, and high-precision processing techniques. Aluminum is the most researched and used material for making TFT buses with low-impedance metals. By solving the problems of easy formation of hillocks, chemical corrosion and oxidation of aluminum, alloy methods (such as Al-Cu, Al-Si, Al-Nd and Al-Ti, etc.) and interlayer methods (such as Mo/Al/Mo) have been reported successively. , Cr/Al/Cr and Ti/Al/Ti, etc.), the alloy method is relatively simple in process, but the material has a higher resistivity. In May 1998, IBM developed a 16.3-inch ultra-high resolution (200ppi) a-Si TFT Display using Al-Nd alloy as the gate electrode, and mass production has been achieved. In April 1999, Toshiba introduced the 20.8-inch 16-SVGA (3, 200 × 2, 400) a-Si TFT-LCD, which can be said to represent the highest level of a-Si TFT-LCD in terms of high resolution and high capacity. .
According to Display Search in the third quarter of 2011, the global flat panel display research report "QuarterlyWorldw ide Flat Pane l Dis play Fore cas t Re port" pointed out that the average pixels per inch (ppi) in large-size LCD panels (>9.1 inches) ) Will grow from 88ppi in 2010 to 98ppi in 2015. The ppi of small and medium-sized LCD panels (<9.0 inches) will grow from 180ppi to 300ppi in the same period. With the rise of smart phones, mobile phones will be the most obvious application product for ppi's growth.
Another important way to realize high-resolution liquid crystal display is to develop LT p-Si TFT technology. The resolution of published p-SiTFT-LCD products is generally around 200ppi. Compared with a-Si TFT-LCD, LT p-Si TFT-LCD has a smaller volume of thin film transistors and storage capacitors. Therefore, it has a larger penetration area per inch, resulting in a brighter display. , And save more power. When the market demands higher ppi, low-temperature polysilicon (LTPS) technology becomes the best choice for manufacturing high-resolution thin-film transistor liquid crystal displays.
Contrast
The control ICs, filters and oriented films used in LCD manufacturing are related to the contrast of the panel. For general users, a contrast ratio of 350:1 is sufficient, but such contrast in the professional field does not satisfy users. Demand. Compared with CRT monitors easily reaching 500:1 or even higher contrast, only high-end LCD monitors can achieve this level. The first-tier LCD monitors on the market, such as Samsung, Asus, LG, etc., can reach a contrast ratio of 1000:1. However, because the contrast is difficult to accurately measure with instruments, you have to go and see it yourself when you pick it.
Tip: Contrast is very important. It can be said that the selection of LCD is a more important indicator than bright spots. When you understand that your customers buy LCDs for entertainment and watching DVDs, you can emphasize that contrast is more important than no dead pixels. We When watching streaming media, the brightness of the source is generally not large, but to see the contrast of light and dark in the scene of the character, the texture change from gray to black hair must be shown by the level of contrast. The 256-level grayscale in the test software In the test, more small gray grids can be seen clearly when looking up, which means that the contrast is better!a
Lcd Display Module,Tft Lcd Screen Display,Display Lcd Enclosure,Tft Display Lvds
ESEN Optoelectronics Technology Co., Ltd, , https://www.esenoptoelectronics.com