When we buy a TV, in addition to the price, the first thing we pay attention to is the quality of the TV.
As the main body of the TV, the screen cost accounts for more than 60% of the entire machine. The concept of "see the screen first when buying a TV" has always been widely circulated among the people.
So, do you know what types of TV screens are divided into? In the current TV market, the frequency of updates is getting faster and faster. Whether it is domestic brands or joint venture brands, many new categories have been launched.
like OLED, QLED... Some new picture quality technologies have once again stimulated the purchasing desire of consumers.
There are too many panel types and screen technologies at present. Not to mention ordinary consumers, even professional players are easily confused. Today I will make a popular summary here.
In fact, the mainstream screen materials on the market are only divided into two categories: LCD ( LCD ) and OLED (organic light emitting diode). It is generally believed that OLED is more advanced than LCD in technology. However, although OLED is in a strong popularity, due to its price, it is still relatively more LCDs.
First, let’s take a look at LCD
LCD is what we usually call LCD. It needs backlight support when displaying content, and the backlight needs to pass through glass, color filters, optical diaphragms, substrates and alignment films to generate polarization, which inevitably leads to loss in color and brightness.
The full name of TFT that is usually referred to is Thin-Film Transistor (thin film transistor).
In LCD, TFT deposits a thin film on the glass substrate as a channel area to improve imaging quality. The upper glass substrate is next to the color filter, and the lower glass substrate is inlaid with transistor .
When the current passes through the transistor, it causes the LCD molecules to deflect, change the polarity of the light, and then use the polarizer to determine the light and dark state of the pixel.
At the same time, the color filters bonded to the upper layer of glass form the three primary colors R, G, and B contained in each LCD pixel, forming the screen displayed on the screen.
After briefly talking about LCD, I will talk about panel type
TN The full name of the panel is Twisted Nematic (twisted nematic panel), which is also one of many panel types.
Due to its low production costs, TN has become the most widely used entry-level panel. Currently, the mainstream mid- and low-end LCD TVs or monitors on the market use TN, and early tablets and mobile phones are also used.
Nowadays, many users equate TN with TFT, which is actually a conceptual confusion.
Due to TN's mature technology and low price, it is still favored by some low-cost products today.
At the same time, TN with high opening rate is more power-saving at the same brightness, and the response speed of 8-15ms is also relatively fast. Therefore, under these advantages, even though TN has disadvantages such as color distortion and narrow perspective, it has not faded out of the market. The full name of
VA panel is Vertical Alignment (vertical alignment panel), which is the type of panel that is more commonly used in high-end LCDs and belongs to a wide-view angle panel.
VA has two types: Fujitsu MVA and Samsung PVA, the latter is the improvement and inheritance of the former.
Compared with TN, VA has a higher contrast, clear and sharp display text, and can also provide a wider viewing angle and better color restoration. The disadvantage is that it consumes a higher power and is higher in price. VA is a soft screen, and ripples will appear when scratched with your hands.
MVA is the full name of Multi-domain Vertical Alignment (Wide Area Vertical Queue), which is a multi-quadrant vertical alignment technology developed by Fujitsu and is produced by technology authorized by Chime Electronics, AUO Optoelectronics and other companies.
However, after the financial crisis, wide-view panel manufacturers all encountered crises.
Qimei and AUO feel that MVA costs high and profits are low, so they stop supplying display manufacturers.
, while LG and Samsung are very market-oriented, and they occupied the past MVA market with C-PVA and E-IPS, which are not much different from TN. The characteristic of
MVA is that the viewing angle, color and color gamut are very good, which is much better than ordinary TN. The disadvantage is that the response time is slightly worse. However, the improved P-MVA viewing angle is close to 178°, and the response time can reach less than 8ms.
PVA's full name is Patterned Vertical Alignment, which belongs to the VA category, is the successor and pioneer of MVA, and its comprehensive quality has surpassed MVA in all aspects. The improved S-PVA can even go hand in hand with P-MVA, achieving extremely short response time and extremely wide viewing angles.
PVA uses transparent ITO electrodes instead of LCD projections in MVA. The transparent electrodes can obtain better opening rate, minimize the waste of backlight sources, and reduce the possibility of LCD "highlights". Its status in the LCD era is equivalent to the "exquisite tube" in the imaging tube era.
IPS is the full name of In-Plane Switching, which is a wide-angle technology launched by Hitachi in 1996.
can effectively improve the problems of TN chromatic aberration and narrow vision when viewing angle is poor. IPS can obtain a visible angle of almost 180°, which greatly improves the shortcomings of TN.
In 1998, Hitachi launched S-IPS (Super-IPS). In addition to the original IPS, it also improves the response speed.
In 1999, LG-PHIHIPS joined the IPS camp as a joint venture manufacturer. After it was declared bankrupt in 2006, the IPS business was mainly handed over to LG Display.
During this period, Hitachi launched AS-IPS in 2002, which made great improvements in contrast.
In the same year, Hitachi also launched IPS-PRO, which is specifically divided into E-IPS, H-IPS and S-IPS.
E-IPS is considered an economical version of H-IPS. The contrast and color are slightly worse than H-IPS, but the color gamut reaches 72%, and the reduction in opening rate increases the visual angle. The most obvious difference between
H-IPS (Horizontal IPS) is that it changes the fish-scale subpixel arrangement of S-IPS. Each pixel is arranged in a straight line, connecting the pixels into a straight line from top to bottom, and each pixel has a smaller electrode width.
H-IPS has slightly improved contrast and color performance compared to S-IPS. It is a relatively high-priced product, while S-IPS has a good cost-effectiveness with its lower price.
Later, LG Display, which took on the IPS task, launched AH-IPS in 2012. Compared with E-IPS, it has made significant upgrades in contrast, power consumption, etc., bringing greater improvements to the display effect.
With the continuous advancement of technology, AIPS has also appeared with better display effects, and the brightness and clarity have been optimized. The difference between
AIPS and IPS is that it is not to direct the LCD molecules into a light-transmitting mode in advance, but to direct the LCD molecules into an opaque mode. The amount of light-transmitting is determined by electrodes perpendicular to the direction of the LCD molecules. The higher the voltage, the more LCD molecules are twisted, thereby achieving precise control of light.
AIPS only controls one deflection angle of the LCD, and the number of deflection molecules can be nearly proportional to the voltage, making it easier for LCD to achieve hierarchical control, and the improvement of dynamic contrast also makes the moving picture perform better. The advantages of
IPS are its cheap price, high viewing angle and accurate color restoration. However, the disadvantage is that the purity of black is not enough, which is slightly worse than PVA, so it needs to rely on the compensation of the optical film to achieve a purer black.
The screen using IPS is relatively "hard", and it is not easy to appear corrugated by scratching it with your hands. It is also what we usually call "hard screen."
Finally, let's take a look at OLED
OLED's full name is Organic Light-Emitting Diode. Unlike the LCD mentioned above, OLED does not require backlight support.
OLED is an innate surface light source technology. The light emitted can be monochrome such as red, green, blue, white, etc., thereby achieving full color effect. It belongs to a new luminous principle. The reason why the image quality of
plasma technology, OLED technology, and even CRT technology in the early years was praised is mainly because they all have the characteristic of "self-luminescence".
OLED technology can turn off independent pixels and reset their brightness to zero. In theory, the contrast of OLED technology can be infinite.
Therefore, it is impossible for OLED to leak light in a black field, thereby improving contrast and image quality performance.
In addition, since OLED technology does not require backlight support, it eliminates LCD and backlight modules. The structure is very simple, and the body can naturally reach the ultimate ultra-thin, which can be roughly 1/3 of the thickness of a traditional LED screen.
OLED also has the characteristics of flexibility and bendability, which can not only be applied to TVs, but may allow smart devices to fill the imagination space in the future.
combined with the thinness of OLED, the screen can be made as thin as a piece of paper and can be bent and folded at will, which is unimaginable in the LCD era.
Finally, I want to say that whether it is LCD or OLED, as long as it exists, it has its meaning.
As consumers, we don’t have to get lost in a bunch of parameters. It’s better to try more and experience the real effect in the store, so that we can choose a product that suits our eyes.
Editor: Li Xiaoshan
