What is E-IPS
As we all know, the quality of a liquid crystal display depends on its panel first, because the quality of the panel directly affects the viewing effect of the screen, and the price of the liquid crystal panel accounts for more than 70% of the cost of the entire display, which affects the cost of the liquid crystal display. The main factor, so to choose a good LCD, you must first choose its panel. At present, the manufacturers of LCD panels are mainly Samsung, LG, AUO, etc. Due to the differences in various technical levels, the LCD panels produced are roughly divided into different types of models. Commonly used are VAs such as TN panels, MVA and PVA. Panel, IPS panel, etc.
IPS is the king of these kinds of liquid crystal panels. 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, and has gathered a number of manufacturers such as LG, Hanyu Caijing, IDTech (a joint venture between Chi Mei Electronics and IBM Japan), but there are not many models that can be seen in the market, and although IPS is developed by Hitachi, However, the follow-up research and development efforts are limited. At present, the IPS panels that we can see on the market are almost all from LG.
E-IPS is an upgraded version of the traditional IPS panel. Similarly, E-IPS also has all the advantages of IPS, and the response is faster and the display is better. It has a wide viewing angle of 178 degrees, no indentation on the panel, sharper colors and no tailing of the image. We know that traditional VA soft screens, whether MVA or PVA, use liquid crystal molecules in a vertical alignment structure and are easily deformed by extrusion. E-IPS is a hard screen, adopts planar conversion technology, and has stable molecular conversion and excellent image quality. In VA soft screen.
From the official E-IPS technical documentation, we can see that E-IPS has more advantages than our familiar VA wide-angle panels. We often say that the viewing angle and display effect of VA is better than that of TN, but compared with E-IPS, it is quite different. This is also related to the special panel structure of the IPS. The two poles of the IPS panel are all on the same surface, unlike the electrodes of other liquid crystal modes, which are arranged on the upper and lower sides, so that the IPS hardly produces smear, while the VA panel The smear phenomenon is more serious, and E-IPS is also a hard screen similar to IPS. The color saturation and brilliance are all unmatched by VA.
There is no doubt that the VA panel is a wide-angle panel, but to be good, the VA panel is inferior to the IPS. When viewed at an angle of 170 degrees or more, the TN is already white, but the VA panel is much better, but the color of the picture will be lighter, which will definitely affect the visual effect. As the strongest wide-angle panel at present, E-IPS has a true viewing angle of 178 degrees without discoloration, so that you can see the perfect picture whether you enjoy it from any angle, which is also a big advantage of IPS leading VA panel. .
What is a TN panel
TN is called Twisted Nematic (Twisted Nematic) panel. The low production cost makes TN the most widely used entry-level LCD panel. It is widely used in mainstream low-end LCD displays on the market. At present, most of the TN panels we see are modified TN+film, film is the compensation film, which is used to make up for the lack of viewing angle of the TN panel. The viewing angle of the improved TN panel is now 160°, of course, this is the manufacturer. The limit value measured with a contrast ratio of 10:1 actually shows distortion or even color cast when the contrast drops to 100:1.
As a 6Bit panel, the TN panel can only display 64 colors of red/green/blue, and the maximum actual color is only 262.144. Through the “jitter” technology, it can achieve more than 16 million kinds of color performance, only 0 can be displayed. 252 gray color of the three primary colors, so the final color display number information is 16.2 M color, instead of what we usually call the true color 16.7M color; plus the TN panel to increase the contrast is more difficult, the problem directly exposed is the color Thin, poor recovery, and unnatural transition.
The advantage of the TN panel is that the output gray level is small, the liquid crystal molecules have a fast deflection speed, and the response time is easy to be improved. Currently, the liquid crystal products below 8 ms on the market basically adopt a TN panel. In addition, Samsung has also developed a B-TN (Best-TN) panel, which is actually an improved version of the TN panel, which must sacrifice the image quality contradiction in order to balance the high-speed response of the TN panel. At the same time, the contrast ratio can reach 700:1, which is close to the panel of MVA or early PVA. Many panel makers in Taiwan produce TN panels, which are soft screens, and similar watermarks appear when you gently stroke them.
What is a VA panel
The VA panel is a panel type with many high-end LCD applications, and it is a wide viewing angle panel. Compared with the TN panel, the 8-bit panel can provide 16.7M color and a large viewing angle is the high-end capital of this type of panel positioning, but the price is also more expensive than the TN panel. The VA panel can be divided into MVA panels led by Fujitsu and PVA panels developed by Samsung, the latter being the inheritance and improvement of the former. The front (right) contrast of the VA panel is the highest, but the uniformity of the screen is not good enough, and color drift often occurs. The sharp text is its killer, and the black and white contrast is quite high.
Fujitsu's MVA technology (Multi-domain Vertical Alignment) is the earliest wide viewing angle LCD panel technology. This type of panel provides a larger viewing angle, typically up to 170°. Through the technology licensing, China's Taiwan Province, Chi Mei Electronics (Qi Jing Optoelectronics), AU Optronics and other panel companies have adopted this panel technology. The improved P-MVA panel can reach a horizontal angle of 178° and the gray-scale response time can be less than 8ms.
Samsung's PVA (Patterned Vertical Alignment) technology is also in the category of VA technology. It is the successor and developer of MVA technology. Its comprehensive quality has surpassed the latter, and the improved S-PVA has been able to keep pace with P-MVA, achieving extremely wide viewing angles and faster response times. PVA uses a transparent ITO electrode instead of the liquid crystal layer protrusion in MVA. The transparent electrode can obtain a better aperture ratio and minimize the waste of the backlight. This mode greatly reduces the possibility of "bright spots" in the LCD panel, and the status in the LCD TV era is equivalent to the "management" of the CRT TV era. Samsung's PVA mode wide viewing angle technology is widely adopted by Japanese and American manufacturers due to its strong production capacity and stable quality control system. At present, PVA technology is widely used in medium and high-end liquid crystal displays or LCD TVs. The VA panel is a soft screen, and a similar water pattern appears when you gently stroke it by hand.
What is a liquid crystal panel
The liquid crystal panel has a close relationship with the liquid crystal display. The production, quality and other factors of the liquid crystal panel are linked to the quality, price and market trend of the liquid crystal display itself. The LCD panel is related to the most important response time, color, viewing angle, contrast and other parameters. From the LCD panel, what is the performance and quality of this LCD monitor? Kobayashi found the information on the LCD panel on the Internet, as long as it is aimed at the current mainstream LCD panel, so that everyone has a bottom in the purchase of LCD monitors.
VA type: VA type liquid crystal panel is widely used in current display products. It is used in high-end products. 16.7M color (8bit panel) and large viewing angle are its most obvious technical features. Currently, VA type panel is divided into two types. Two kinds: MVA, PVA.
MVA type: Full name (Multi-domain Vertical Alignment), is a multi-quadrant vertical alignment technology. It uses the protrusions to make the liquid crystal stand still not the traditional upright type, but is biased to a certain angle at rest; when the voltage is applied to change the liquid crystal molecules to the level to make the backlight pass faster, the display time can be greatly shortened. Also, because the protrusions change the alignment of the liquid crystal molecules, the viewing angle is wider. The increase in viewing angle can reach more than 160 degrees, and the reaction time is shortened to within 20ms.
PVA type: It is a panel type introduced by Samsung. It is an image vertical adjustment technology. This technology directly changes the structure of the liquid crystal cell, so that the display performance can be greatly improved to obtain brightness output and contrast superior to MVA. In addition, based on these two types, the improved S-PVA and P-MVA panel types are extended, and the technology development is more upward, the viewing angle can reach 170 degrees, and the response time is controlled within 20 milliseconds ( Updrive is used to achieve 8ms GTG), and the contrast can easily exceed the high level of 700:1. Most of Samsung's products are PVA LCD panels.
IPS type: IPS type liquid crystal panel has the advantages of large viewing angle and fine color, and it looks transparent. This is also a method to identify IPS type liquid crystal panel. PHILIPS many liquid crystal displays use IPS type panels. S-IPS is the second-generation IPS technology, which introduces some new technologies to improve the gray-scale reversal of IPS mode at certain angles. LG and Philips' own panel makers are also introducing LCD panels with IPS technology.
TN type: This type of liquid crystal panel is used in both entry-level and mid-range products. It is affordable and inexpensive, and is used by many manufacturers. Technically, compared with the first two types of liquid crystal panels, the technical performance is slightly inferior, it can not show 16.7M brilliant color, only 16.2M color (6bit panel), but the response time is easy to improve. The viewing angle is also limited, and the viewing angle does not exceed 160 degrees. Most of the products currently on the market within 8ms response time are TN liquid crystal panels.
The production of liquid crystal panels is a process that covers multidisciplinary and multidisciplinary knowledge, including semiconductors, physics, chemistry, electronics, mechanics, optics, chromatics, thermals, and more. It's hard to explain in a short space, you can write a lot of books, huh, huh. Mainly on the two glasses, respectively, using semiconductor process sputtering and etching to form matrix lines, semiconductor switches, color filters, etc., and then brush a layer of the liquid crystal molecules in one direction, and then drop Or fill the liquid crystal into two layers of glass and seal it to form a liquid crystal cell, attach the polarizer to the upper and lower glass, then connect the signal control circuit board to the liquid crystal cell, and then assemble a backlight that can provide light, which constitutes A liquid crystal panel. Each of the above steps is a complex process. This is probably the case in a simple way.
Introduction to the LCD panel
When users buy LCD monitors, they often listen to the merchants saying: "The xx card is good, the A screen is used, the xx card is not used, and the B screen is used." What is the difference between the A screen and the B screen?
The A-level screen is higher than the B-level screen, and the C-level is the lowest. In addition to these three levels, there is now a title called "Super A" or "AA", which is slightly higher than the A grade. Generally speaking, both the B and C grades are depreciated. Compared with the A grade, the B and C grades have more bad points, the brightness is relatively uneven, the appearance may be damaged, and the price gap with the A-class screen. It may be as high as nearly a thousand dollars.
For the well-known brands such as Samsung, Philips, and Pure, the quality requirements for LCD screens are relatively high, and “A” screens are used to ensure quality. Therefore, in the procurement process, the price is not completely positioned according to a simple brand, but rigorously follows a principle of cost manufacturing.
The dead pixel is the unrepairable pixel on the LCD panel, which is generated during the production process. There are three transistors behind the liquid crystal pixel, corresponding to three filters of red, green and blue. Any one of the transistors has a problem that makes this pixel a bad point. In the case of a 15-inch 1024*768 screen, a total of about 1024*768*3=2359296 pixels is required, and a separate drive tube is integrated behind each liquid crystal pixel, in so many pixels and drive tubes. Inevitably there will be problems in individuals. The number of dead spots is directly related to the manufacturer's technical and process level. For the time being, the liquid crystal panels produced in each batch usually have 20% of the products with dead pixels. With the continuous improvement of technology, the dot-maturity rate of some brands of LCD panels can be controlled to within 10%, but the zero-dot rate is still rare.
The highlight is the red and green bluish dots displayed on the screen when the screen displayed on the setting screen is completely black.
A dark spot is a point at which the color is not displayed on the screen when the screen displayed on the screen is all white or the same color.
In fact, the discrimination of the liquid crystal panel is not only the number of dark spots and bright spots. The difference between color purity and viewing angle is also the main basis for evaluation. According to the comprehensive evaluation of these product pointers, the liquid crystal can be scored as A grade. Class B and Class C, and will use this as a basis for pricing products. The A-level screen and the B-level screen must be tested with special instruments, which are difficult to discriminate with the naked eye.
The panel manufacturers in different regions have different classifications of products: Korean manufacturers, 3 or less are Class A
Japanese manufacturers, 5 or less are Class A
Taiwanese manufacturers, 8 or less are Class A
The standard grades for mainstream LCD products are:
AA level: LCD display without any dead pixels is AA grade.
Class A: 3 points below the dead point, where there are no more than one bright spot, and the bright spot is not in the center of the screen.
Class B: Below 3 bad points, no more than two bright spots, and the highlights are not in the center of the screen.
The above is the grading standard of LCD panel manufacturers and LCD monitor manufacturers, for everyone to choose when choosing LCD!
Analysis of the development of LCD TV industry in China
With the development of China's economy and the improvement of people's living standards, LCD TV, as an important household appliance, plays an increasingly important role in national economic production and people's social life. In the new century, China's LCD TV industry has accelerated its development and achieved gratifying results.
While the Chinese LCD TV industry is developing, some problems are also emerging. In particular, the LCD TV industry standard is not perfect, the manufacturing cost remains high, the price war is getting more and more fierce, and many competitive enterprises lead to low profit in the industry, which seriously restricts the further development of the industry and the improvement of quality.
Therefore, Chinese LCD TV companies must seize the new development situation, increase technological innovation, improve technology content, strengthen independent research and development capabilities, create effective promotion strategies, and unify the national standards of the LCD TV industry.
