What is the difference between ips and va. TN vs IPS. Which monitor to choose
*VA(Vertical Alignment) The first matrix of this type, which was called “VA”, was developed by Fujitsu. Subsequently, these matrices were improved and produced by a number of companies. They are characterized as a compromise in most characteristics (including cost and power consumption) between TN and IPS, as well as the latter leaving the faulty pixel or sub-pixel in a dark state. Their main advantage is high contrast combined with good color rendition (especially the latest options), but unlike IPS they have a negative feature, which is expressed in the loss of details in the shadows when viewed perpendicularly and the dependence of the color balance of the image on the viewing angle.
- MVA - Multi-domain Vertical Alignment. The first widespread type of matrices from this family
- PVA (Patterned Vertical Alignment) - developed *VA technology, proposed by the company, characterized primarily by increased image contrast.
- S - PVA (Super-PVA) from ,
- S - MVA (Super MVA) from Chi Mei Optoelectronics,
- P-MVA, A-MVA (Advanced MVA) from AU Optronics. Further development of *VA technology from various manufacturers. The improvements boiled down mainly to reducing response time by manipulating the feed more high voltage at the initial stage of changing the orientation of the subpixel crystals (this technology is called either “Overdrive” or “Response Time Compensation” in different sources) and the final transition to full 8-bits encoding color in each channel.
- IPS Pro (developed by IPS Alpha) - used in Panasonic LCD TVs.
- AFFS - compact matrices manufactured by Samsung for special applications.
- ASV - matrices produced by Sharp Corporation for LCD TVs.
To work with office applications, any LCD monitor will suit you perfectly, so you can safely choose based on the design, price of the device and other considerations. The only remark is that if you buy a monitor with large diagonal– 20” and above, it is advisable that it be connected via DVI interface, because when working with texts and tables, the highest possible image clarity is desirable. (When buying a cheap monitor for gaming and watching movies, availability digital input not so critical.)
To work with raster graphics(photo processing, etc.), as well as video editing, and any other applications where reliable color reproduction is critical, you should choose models with an IPS family matrix or, which is somewhat worse, in this case, *VA.
In many situations, a monitor with an IPS matrix can also be a very good choice for the home, since the only significant drawback of modern ones of this type is the relatively high price. And although the response time exceeds that of the best TN monitors, it does not impose any restrictions on the use of such monitors in games.
Likely, the best option as a universal home monitor For many users, there may be an option with a modern *VA matrix, since it provides a much more comfortable viewing of movies and photos than cheaper TN options, and the speed characteristics will be sufficient for most users except the most hardened gamers.
If the monitor is purchased primarily for 3D games (especially shooters and simulators), a TN matrix may be an adequate choice; when used in games, the main disadvantages of this technology are not so noticeable. In addition, these monitors are the cheapest. (If we compare models with the same diagonal).
Modern monitors also differ in screen aspect ratio - regular, with an aspect ratio of 4:3 or 5:4, and widescreen, with an aspect ratio of 16:10 or 16:9.
Since the binocular field of vision of a person has an aspect ratio much closer to those of , then, other things being equal, it is theoretically more comfortable to work with them and they are gradually replacing those with a “normal” aspect ratio. Some problems may only occur with older games that do not support video modes with the appropriate aspect ratio, but practice shows that in such cases adaptation to a “flattened” image occurs very quickly and this fact does not cause discomfort. So we recommend choosing the monitor aspect ratio based on your own preferences, although “for home” widescreen monitor definitely more convenient.
We also recommend relying on your own subjective impressions when choosing the type of coating for a monitor, a “glossy” coating makes the image visually more contrasting (especially on cheap matrices), but it glares much more and more unpleasantly, unlike matte.
We remind you that very often the overestimation can be caused not only by the use of an expensive and high-quality matrix, but also by features that are not directly related to the monitor’s performance of its main function, i.e. the presence of specific peripherals (speakers, subwoofers, web cameras), additional inputs (digital, for example, a second DVI or HDMI, and analog, such as S-Video or component input) or unique design solutions.
A visual comparison of the influence of viewing angles (photos taken at an angle of 50°) on the image characteristics of monitors with various types matrices:
     Indicative table of comparative user characteristics depending on the type of matrix used:
Just a few years ago, choosing a monitor for a personal computer was based on price category, where it was clear that the more expensive device has a high-quality matrix, and the cheap monitor does not shine with characteristics. On at the moment In the monitor market, the division occurs by screen size; each manufacturer produces devices with different technologies matrices. Because of this, the purchasing choice has become more complicated. This article will help users choose the right monitor matrix type. Which screen is best to purchase on the market, for what purposes and how it differs from competitors will be presented in an accessible form.
To make it clearer
Before choosing the type of monitor matrix, you need to understand the principle of its operation, as well as identify all the advantages and disadvantages. Having compiled a list of needs (for what purpose is it purchased? this device), it will be very easy to compare the actual with the desired. If you do not affect the screen size, the use of the monitor is distributed according to needs into several groups:
- Office monitor. High level contrast is the only requirement.
- Designer's computer (photo, pre-press). Accurate color reproduction is important.
- Multimedia. Watching movies requires wide viewing angles and true black color on the screen.
- Gaming computer. Important indicator- matrix response time.
The production technology and the movement of electrons between matrices is unlikely to be of interest to anyone, so this article will discuss the advantages and disadvantages, and also use data from the media - reviews from owners and recommendations from sellers. Having found out what technologies exist, all that remains is to combine them with the stated requirements and the funds allocated for the purchase of the monitor.
The state employee does not give up positions
The TN (Twisted Nematic) monitor matrix type is considered a long-liver among its competitors on the market. Due to its low price and availability, monitors with this matrix are installed in all government and educational institutions, offices of many companies around the world and in large enterprises. According to statistics, 90% of all monitors in the world have a TN matrix. Along with the price, another advantage of such a monitor is the short response time of the matrix. This parameter very important in dynamic games where rendering speed is of paramount importance.
But the color rendering and viewing angle of such monitors did not work out. Even upgrading the TN matrix by adding an additional layer to increase viewing angles did not give desired results, just added “+film” to the name of the screen type. We must not forget about energy consumption, which significantly exceeds the operating mode of all competitors.
And yet
Apart from office use, TN+film is the best type of monitor matrix for gaming. After all, most gamers prefer to overpay for high-performance components such as a processor or video card, but they can save money on the screen. However, do not forget about color rendering; in modern games, developers try to make the plot as realistic as possible, and without a real rendering of all colors and shades, this will be very difficult to achieve.
As a result, apart from the low price and short response time, the TN matrix will not be able to surprise a potential buyer with anything. After all, it is very difficult to ignore the shortcomings:
- Low color rendering with the inability to display perfect blacks. The defect is visible when watching dynamic films where all the action takes place in the dark - “Van Helsing”, “Harry Potter and the Deathly Hallows”, “Dracula” and the like.
- Low cost of production leads to a high probability of acquiring a defective matrix, dead pixel which is immediately visible, because it is painted white.
- Very low viewing angles do not allow you to contemplate the picture on the screen with a large family.
A step in the right direction
The monitor matrix type VA (Vertical Alignment) uses technology with vertical ordering of molecules, and in the post-Soviet space is better known under the MVA or PVA markings. And more recently, the suffix “S”, which stands for “Super,” was added to the existing modifications, but the monitors did not acquire any special characteristics compared to their competitors, except that they became slightly more expensive.
VA technology was intended to eliminate defects in TN+film matrices, and manufacturers were able to achieve certain results, but when comparing these two screens, the user will find that they have opposite characteristics. That is, the disadvantages of VA matrices are the advantages of TN, and the advantages of VA are the disadvantages of cheap matrices. What the manufacturers were thinking is unknown, but the situation on the market has not yet changed for these matrices, even with the introduction of the “Super” label.
Advantages and disadvantages of VA technology
If VA technology is compared with the cheapest matrix on the market, TN+film, then the advantages are obvious: excellent viewing angles, very high-quality color reproduction with deep blacks. In fact, this type of photo monitor is the best in its price range. The only thing that confuses me is the response time. Compared to a cheap TN screen, it is several times higher. Naturally, a device with such a matrix will not be suitable for game lovers, since the dynamic picture will be constantly blurred.
But designers, layout designers, amateur photographers and all professionals who need to work with real color and its shades will like monitors with VA technology. Besides this, wide angle viewing even with a strong tilt does not distort the image on the screen. Such monitors are suitable for multimedia - watching any films with your family will be interesting, because the screen provides the opportunity to see real black color, and not its semblance in the form of fifty shades of gray.
Without flaws?
IPS matrices and their various modifications have been on the market for quite a long time. However, their cost is not as attractive to buyers as the impeccable characteristics of screens that use an expensive type of monitor matrix. Which screen is better for a businessman and designer, the president of a company or a traveler, only Apple company, because all its devices, without exception, have IPS (In-Plane Switching) matrix technology.
From year to year, all kinds of technologies appear, experts are trying to improve the quality of an already expensive and high-quality matrix, as a result of which there are a number of modifications on the market: AH-IPS, P-IPS, H-IPS, S-IPS, e-IPS. The difference between them is minor, but it is there. For example, e-IPS (Enhanced) has technology that increases screen contrast and brightness, and also reduces response time. The professional P-IPS series can display 30-bit color, but it’s a pity that the user will not clearly notice this.
Reach your dreams
Without going into deciphering the modifications of the IPS matrix, you can see that this technology is a kind of symbiosis of VA and TN+film production. Naturally, only the advantages were selected that were embodied in one device. For example, the type of monitor matrix AH-IPS (Advanced High performance) is a direct competitor plasma panels, which have no analogues in the world in terms of the quality of high-definition picture reproduction. Such a serious statement was made back in 2011, however, in addition to the inflated price for a device with AH-IPS matrix it has not yet been possible to prove superiority.
And yet, if a game lover has a question about which type of monitor matrix to choose - IPS or TN, then the right decision would be to purchase a more expensive and high quality screen. Even though the price of the device is several times higher than its cheap competitor, spending time with your favorite toy will be more interesting. After all, realistic picture quality will always remain in first place.
Fun games manufacturers
We will talk primarily about the Korean giant Samsung, which is constantly trying to invent new technology, but he doesn’t always succeed, because along with quality, the buyer is also interested in the cost of the device, which for some reason tends to increase disproportionately.
By introducing single pixel separation technology, Samsung was able to achieve better image clarity. First of all, this is noticeable on the screen when typing small print multi-colored text. The technology was approved by many layout designers, and PVA-labeled monitors quickly found fans.
The WVA monitor matrix type was an improved version of technology from Samsung, and, judging by the low cost of the devices, it competed freely in the market. The shortcoming with the matrix response speed in all devices created using VA technology has not been eliminated.
Radical solution
The type of monitor matrix AH-IPS was of interest only to buyers in developed countries of the world. After all, for best quality you have to pay a very large sum, which is beyond the means of residents of the post-Soviet space. And there is no point in purchasing a monitor that is a little more expensive than a modern one personal computer assembled. Therefore, manufacturers of expensive devices had to reduce the cost of technology by reducing the quality in the production of components. So it appeared on the market new type matrices monitor pls(plane-to-line switching).
After analyzing the characteristics and studying the operating principle of the new matrix, you might think that this is just an improved modification of the PVA matrix from Samsung. That's true. As it turned out, the manufacturer developed this technology a long time ago, but its implementation occurred quite recently, when there was a huge price difference between middle-class and expensive devices, and there was an urgent need to fill the empty price niche.
Who won?
Apparently, this is the only case when in the war between manufacturers for the sales market, the buyer wins, who receives a worthy device in terms of its characteristics at a price that is quite acceptable to him. The disadvantage is the small selection of manufacturers, because Samsung has not released the technology beyond its concerns, so the Korean brand has few competitors - Philips and AOC.
But, faced with the choice of which type of monitor matrix is better - IPS or PLS, a potential buyer who decides to save money will definitely give preference to the latter. After all, in fact, there is not much difference between the devices. And if you pay attention to the fact that most mobile devices, including tablets, have a PLS matrix, which is very often presented by the seller as a more expensive IPS, then only one conclusion suggests itself.
In pursuit of perfection
Not long ago, Sharp introduced a type of monitor matrix made using IGZO (indium, gallium and zinc oxide) technology. According to the manufacturer, the material has very high conductivity and lower power consumption, thanks to which it was possible to achieve more high density pixels per square inch. Essentially, IGZO technology is suitable for the production of 4K monitors and all mobile devices produced in Ultra HD format.
The technology is far from cheap, and prices for monitors and TVs with IGZO matrix are breaking world records. However, the well-known company Apple got its bearings very quickly, concluding contracts with the matrix manufacturer. This means that this technology is the future; all that remains is to wait for the price to drop on the world market.
Best choice for gamer
Having studied existing production technologies, you can without hesitation determine which type of monitor matrix is better. For games, response time and color rendition are a priority, so the choice here is limited. For those who want to save money, a device with a PLS matrix is quite suitable. Although the choice among manufacturers is small, it is possible to decide among the modifications. In addition to the standard type of matrix, the manufacturer offers an improved Super-PLS model, in which the brightness and contrast are higher, and the screen allows you to display a resolution exceeding FullHD.
But if the price of the issue is not critical for the buyer, then an IPS screen will allow you to enjoy the most realistic picture. You won’t be able to get confused in the markings, because they all boil down to improving the viewing angle and dynamic contrast. The only difference is the price - the better, the more expensive. Having given preference to a device with a matrix type IPS monitor, the gamer can't go wrong.
Photo processing and graphics are a priority
It is clear that an IPS device is suitable for designers and layout designers. But is there any point in overpaying? After all, photo processing and layout involve working with colors and their shades. The response time of the matrix is not considered at all. Professionals recommend not to waste money and choose a VA type of monitor matrix. Yes, this is old technology, yes, this is the last century, but in terms of “price-quality” criteria, matrices of this type have no competitors. And if you want to purchase some of the new products, then you can opt for a PLS matrix.
If there is a need to work behind a monitor with high resolution, for example 4K, then professionals recommend giving preference to IGZO devices. Their price is not so far from the popular IPS screens, but they are undoubtedly better in quality.
Multimedia lovers can save money
Oddly enough, but for those who like to watch movies on a monitor screen and surf the Internet, purchasing a device with a TN+film matrix is quite enough. An inexpensive gadget with an improved screen can easily replace a small TV. The problem can only appear in dark dynamic scenes, where instead of a black background the viewer will have to observe a gray cloud. If this is critical, you need to look towards VA matrices. Yes, the price is higher, but the problem with color rendering will be solved. In addition, the buyer will receive very high contrast and large viewing angles. Don't forget about the physical resolution of the matrix - the higher it is, the better the picture.
Office option
It would seem that the universal type of TN+film monitor matrix would be perfect for working with text. But, as practice shows, working with small print behind such a screen is extremely inconvenient. And if a monitor is purchased specifically for working with large volumes of text, then you should worry about your vision. The closest technology to TN at an affordable price is VA. Regardless of the manufacturer and screen size, such a device will allow you to sit at the computer for more than one hour without any problems.
When choosing a monitor for office work, attention should be paid to both the size and physical resolution of the matrix. The diagonal of the screen for working with text should not exceed the distance from the user’s eyes to the matrix. It is also recommended to select office monitors with an aspect ratio of 4:3, because in this ratio more readable information is placed on the screen.
New trend: for your loved one
Having studied all existing technologies of liquid crystal screens, before choosing the type of monitor matrix, a potential buyer should get acquainted with the information obtained through user surveys in the media.
- The monitor is a durable purchase. That is, the next acquisition, with a high probability, will not be earlier than in 10 years.
- In 99% of cases, the stated requirements for equipment do not coincide with operating conditions. That is, gaming battles are going on on the office monitor, but only news feeds are viewed on elite devices.
- Multi-connection. For convenience, 25% of users in the world connect several monitors (2, 3, 4) to one computer, and the number of such owners is constantly growing. The convenience is that each connected device has a specific role - games, movies, office, etc.
The above information allows you to rethink your earlier knowledge. It is recommended to make a purchase based not on needs, but on desire and capabilities. Essentially, you should focus on the most expensive and high-quality device that the user can afford. You can't save money here.
In conclusion
Having found out which type of monitor matrix is best for the user, what the letter markings on the device’s display mean and how it affects price and quality, you can begin to select the diagonal. However, many IT experts recommend paying attention to the resolution of the screen - how many dots per square inch it can display. Very often right choice the required resolution leads to the purchase of a monitor with a smaller diagonal, and, accordingly, to significant savings cash. An important role is played by the manufacturer of monitors - the matrix is of its own production, the availability service center by place of residence and large warranty period hint to the future owner that he is acquiring a worthy device that will never let you down.
Matrix type is one of the most important parameters of modern LCD monitors. This is the technology used to produce the display. The LCD matrix is flat plate package made of glass, between which are liquid crystals or substance based polymer materials.
Among all the variety currently available by matrix type, monitors classified Thus:
- TN(twisted nematic)
- IPS(in-plane switching)
- PLS(plane-to-line switching)
It is worth noting that there are others, but they are present moment not as popular as the above. In physical form, these technologies vary geometry of surfaces, front electrode, polymer and control plate.
Which matrix to choose
Let's take a closer look at what these 3 types are, advantages And flaws each of them. Let's give recommendations, what you need to be guided by when choosing a particular monitor to purchase.
Monitors with Tn matrix
Most simple technology and common. The percentage of monitors with this matrix currently exceeds 80%. The reason for this is cheapness their production, therefore their cost is the lowest.
But this is not the only plus. Such displays durable, their energy consumption relatively low. Many gamers will be pleased response time– from 2 ms, this figure is unattainable for other types. They have high frequency characteristics, which can also be useful in some dynamic games.
Now about cons– there are quite a lot of them. Firstly, picture quality These monitors leave much to be desired - you will not be able to get ideal color rendition. For those with very sensitive eyes, these displays are clearly won't fit– your eyes will get tired quickly. In addition, such screens have smallest angles review.
Letting down results, this type of matrix is suitable if you want save money your budget, spend a short time at the computer, and watch movies more often in low resolution. Whether it's worth saving depends on your needs and the thickness of your wallet.
IPS technology
Picture quality in this case the maximum realistic. Huge number of displayed flowers And shades– over one billion. There are many varieties IPS, they all have the best in common contrast And maximum viewing angle compared to TN.
The picture shows a clear difference in the matrix TN(left) from IPS(right).
Improved response time in dynamically changing images, it may be possible to have trails. Cost price production is higher, hence - high price. But it's worth it - IPS screens can already compete with plasma panels.
Screens with PLS matrix
PLS is modification IPS matrices. Developed by Samsung, as its alternative.
What has changed? Thanks to higher density pixels maximum brightness And color rendering increased. Energy consumption comparable to TN. Better response time than IPS, but still falls short of TN. But overall difference PLS and IPS, all other things being equal (diagonal, aspect ratio, resolution, backlight type) little noticeable. Regarding prices, then pls several cheaper.
To summarize the above, if you are an avid gamer, professional photographer or designer or strive to be like this, that is, it makes sense to spend money and buy a monitor with IPS or PLS matrix. If the computer is used for standard office tasks and drawing graphics - take a closer look at the displays based on TN technology. Be guided by personal preferences and make the right choice.
Over the years of television development, many changes have occurred in technologies for displaying images on the screen. Image quality improves every year, making recently released brands obsolete. But at the same time, all types of screens, be it televisions, smartphone displays or computer monitors, are built on the basis of matrices. The heroes of this article will be the VA and IPS matrices.
Most of the display characteristics, such as color and resolution, depend on the matrix. Therefore, when choosing your new device, it is better not to rely at random, but to choose after carefully analyzing all possible options.
This matrix appeared in 1996, presented by the Japanese company Fujitsu. Its name stands for Vertical Alignment, which literally translates as vertical alignment . Since its appearance on the market, it has gained high popularity and its range of applications includes modern LCD TVs.
Its peculiarity is that its liquid crystals, in the absence of power, are located perpendicular to the screen. This provides it with its main advantage among its peers - a very rich black color. The viewing angle when using this technology is also quite high. As for the disadvantages of such a matrix, first of all it is for a long time response. This prevents the use of such matrices in monitors designed for frequent image changes, for example, for computer games.
Also adding some inconvenience are the so-called "Floating Halftones" expressed in the fact that when shifted from the center of the display, part of the color palette begins to be distorted. But in most cases it is practically unnoticeable. Regarding IPS technology, it is intermediate between the previous TN and S-IPS. They are easier to produce, making them cheaper, and their characteristics are similar to IPS matrices. During its creation, several modifications were created; its improvements include:
- MVA, the pixel is built from two parts, which adds sharpness to the image.
- P-MVA features increased contrast and color rendition.
- AMVA– It fixed the main drawback of VA - response.
Main characteristics of IPS
It appeared on the market in 1996, immediately becoming a competitor to VA. Since two manufacturers took part in the creation, it received a double name. In Plane Switching from Hitachi and Super Fine TFT from NES. The priority in creation was to create a display without the typical disadvantages of TN. Among its competitors, the factors that make IPS stand out are its wide viewing angle, good contrast characteristics and high color rendering ability.
Monitors with IPS are thicker than those built on the basis of other matrices. This design feature appeared due to the need to use lamps with higher power. A model with a backlit matrix with increased light transmittance is often used on tablets and smartphones.
Main Application similar devices found in professional processing photos and rendering 3D models. They are also often used when editing books and collections before publication. They have found their place due to their high color rendering characteristics, contrast and the ability to very accurately display all possible shades. Since its release it has been modified many times. The most significant modifications were:
- The first modification of the classic scheme was the S-IPS matrix. Created in 1998, contrast and response have been improved.
- The next step was the 2002 matrix - Advanced Super IPS(AS-IPS). The main improvements were improved image brightness and contrast.
- In 2007, the H-IPS matrix appeared especially for photographers and designers, in which the shades of white were comprehensively redesigned.
- In 2010 it was developed Professional-IPS, it now supports color space up to 102 bits. The number of colors displayed has exceeded 1 billion. The mode has been optimized Truecolor. It was a deeply modified H-IPS matrix.
- In 2009, they released a version that was cheaper compared to other matrices, called Enhanced-IPS. It uses lower quality hardware to reduce production costs. At the same time, response time has improved significantly. Some pixels were trimmed, degrading the quality of halftones and the number of colors.
- Also in 2011 Korean manufacturer Samsung a new type was introduced and received the technical designation Plane-to-Line Switching. The pixel density in PLS matrices is higher than that of analogues, due to which the brightness increases. Also, when using such a scheme, energy consumption improves. But at the same time, the contrast and color gamut are much lower than those of analogues. PLS is used in tablets and smartphones of this company.
Similarity
Apart from the function and year of production, these matrices are not similar in any way.
Difference between IPS and VA technologies
The placement of liquid crystals in an IPS matrix is horizontal by default, while in VA it is vertical, based on this, only horizontal movement of crystals is possible in VA matrices, while vertical movement in IPS matrices is possible. In the absence of power supply to the crystals, vertically arranged crystals are located more closely together, which provides VA technology with better light blocking. This provides rich black tones.
In another technology, the crystals allow much more light to pass through when closed. However, this also distorts the image on TVs with VA technology when deviating from right angles. Conversely, on TVs with IPS matrices the image will not float even at very large angles. So the main advantages of VA are contrast and deep blacks, while IPS takes its toll in viewing angles.
The black level in the VA matrix reaches 0.015 nits, but when using IPS it is several times higher. Therefore, the image obtained on the VA matrix in darker rooms will differ increased quality. As for color rendering levels, the characteristics of both matrices are approximately equal. However, due to the same black levels and contrast, most viewers find that VA produces brighter colors.
What to give preference
If your home is different large size, and you are going to often watch TV in a large company, then IPS advantage technology will be obvious to you. Viewing angles, without loss of quality, are approximately twice as high as those of a competing matrix. This will give you the opportunity to watch your favorite shows from anywhere in the room. In addition, screens with this technology consume much less electricity.
The VA matrix is suitable for watching movies in the evening, after work, in excellent quality. It will always have bright colors and shades. In addition, such matrices will be cheaper to produce than IPS, which will allow you to save a little. However, at the moment, both of these technologies have comparable characteristics and therefore it is up to you to decide which advantages of which matrix are closer to you.
Liquid crystals were discovered back in 1888. But practical application they found it only thirty years ago. “Liquid-crystalline” is the transition state of a substance in which it acquires fluidity, but does not lose its crystalline structure. The greatest practical interest, as it turns out, is the optical properties of liquid crystals. Thanks to the combination of a semi-liquid state and a crystalline structure, the ability to transmit light can be easily changed.
Types of LCD matrices
The first mass product using liquid crystals was electronic watch. The monochrome display consisted, as is known, of individual fields filled with liquid crystals. When a voltage is applied to order the crystals, the desired fields block the passage of light and appear black against a light background. Color displays appeared when the cell sizes were significantly reduced and each cell was equipped with a color filter. In addition, modern LCD monitors use backlighting.
For illumination, usually 4 or 6 lamps and mirrors are used to ensure uniformity. The operation of an LCD panel is based on the polarization of light. On the way luminous flux two polarizing films with perpendicular polarization directions. That is, in total, these two films block all the light. Liquid crystals located between the films reverse part of the flow polarized by the first film and thus regulate the glow of the screen.
LCD matrix subpixel circuit.
Each pixel is made up of blue, red and green subpixels
A layer of liquid crystalline substance is “sandwiched” between two guide films with tiny notches, in the direction of which the crystals line up. You can change the orientation of the crystals, for example, using an electrical pulse, as is done in the matrices of LCD monitors. In modern matrices, each cell has its own transistor, resistor and capacitor. Actually, in color matrices, each pixel represents three cells: red, green and blue.
Matrix TN. The oldest and most common
The oldest type of matrices that are currently used is TN. The name of the technology stands for Twisted Nematic. Nematic liquid crystalline substances consist of elongated crystals with spatial orientation, but without a rigid structure. Such a substance is easily susceptible to external influences.
In TN matrices, the crystals are aligned parallel to the screen plane, and the upper and lower layers of crystals are rotated perpendicular to each other. All the rest are “twisted” in a spiral. Thus, all transmitted light is also twisted and passes unhindered through the external polarizing film. So when the TN matrix cell is turned off, it glows, and when voltage is applied, the crystals gradually rotate. The higher the voltage, the more crystals unfold and the less light passes through. As soon as all the crystals turn parallel to the light flux, the cell “closes”. But for TN matrices it is very difficult to achieve perfect black.
The crystals in the TN matrix are “twisted” in a spiral (1).
When voltage is applied, they begin to rotate (2).
When all the crystals are perpendicular to the surface (3), no light passes through.
The main problem of TN matrices is the inconsistency in the rotation of the crystals: some are already completely rotated, others have just begun to rotate. Because of this, the light flux is scattered and, ultimately, the picture does not look the same from different angles. Horizontal viewing angles of modern matrices can be considered acceptable, but when rotated vertically, even within small limits, the distortion is significant. The color rendering of TN matrices is far from ideal - they, in principle, cannot display the full palette of colors; I compensate for the lack of shades using cunning algorithms. Such algorithms, with a frequency invisible to the eye, alternately reproduce in the cell the shades closest to the one that cannot be reproduced. But TN technology provides maximum speed cell actuation, minimal power consumption and as cheap as possible. These two circumstances make the oldest technology the most popular and most widespread.
IPS. Ideal for photos and graphics. But expensive
The second in development time was IPS technology(In Plane Switch). Such matrices are produced by Hitachi and LG.Philips factories. NEC produces matrices made using similar technology, but with its own abbreviation SFT (Super Fine TFT).
As the name of the technology suggests, all crystals are located constantly parallel to the plane of the panel and rotate simultaneously. To do this, it was necessary to place two electrodes on the underside of each cell. When turned off, the cell is black, so if it is dead, there will be a black dot on the screen. And not constantly glowing, like TN.
In an IPS matrix, the crystals are always parallel to the screen surface
IPS technology provides the best color reproduction and maximum viewing angles. Significant disadvantages include a longer response time than TN, a more noticeable interpixel grid, and a high price. The improved matrices were called S-IPS and SA-SFT (from LG.Philips and NEC, respectively). They already provide an acceptable response time of 25 ms, and the newest ones are even less - 16 ms. Thanks to good color rendering and viewing angles, IPS matrices have become the standard for professional graphic monitors.
MVA/PVA. A reasonable compromise?
The technology developed by Fujitsu can be considered as a compromise between TN and IPS VA (Vertical Alignment). In VA matrices, the crystals in the off state are located perpendicular to the screen plane. Accordingly, the black color is ensured as pure and deep as possible. But when the matrix is rotated relative to the viewing direction, the crystals will not be visible in the same way. To solve the problem, a multi-domain structure is used. Fujitsu's Multi-Domain Vertical Alignment (MVA) technology features protrusions on the plates that determine the direction in which the crystals rotate. If two subdomains rotate in opposite directions, then when viewed from the side, one of them will be darker and the other lighter, so for the human eye the deviations cancel out. There are no protrusions in PVA matrices developed by Samsung, and the crystals are strictly vertical when turned off. In order for the crystals of neighboring subdomains to rotate in opposite directions, the lower electrodes are shifted relative to the upper ones.
In VA type matrices, when turned off, the crystals are perpendicular to the screen surface
To reduce response time, Premium MVA and S-PVA matrices use a dynamic voltage increase system for individual sections of the matrix, which is usually called Overdrive. Color rendition of PMVA and SPVA matrices is almost as good as that of IPS, response time is slightly inferior to TN, viewing angles are as wide as possible, black color is the best, brightness and contrast are the highest possible among all existing technologies. However, even with a slight deviation of the direction of view from the perpendicular, even by 5–10 degrees, distortions in halftones can be noticed. For most, this will go unnoticed, but professional photographers continue to dislike VA technology for this.
What to choose?
For home and office use, price is often the deciding factor, and because of this, TN monitors are the most popular. They provide acceptable image quality with minimal response time, which is a critical parameter for fans of dynamic games. PVA and MVA matrices are not as widespread due to their higher price. They provide very high contrast (especially PVA), a large margin of brightness and good color rendition. As a basis for homemade multimedia center(TV replacement), this best choice. IPS matrices are increasingly rarely installed in monitors with a diagonal of up to 20 inches. The best S-IPS and SA-SFT models are not inferior in quality to CRT monitors and are increasingly used by professionals in the field of photography, printing and design. Practical recommendations on choosing a monitor can be read in the article “Choose an LCD monitor. What should a photographer, gamer and housewife prefer?
Let's dream a little
Quite recently, i.e. 15 years ago, it’s unlikely that many would have imagined that LCD monitors would be able to supplant CRT monitors. The LCD quality was poor and the price extremely high. But even now the technology for producing liquid crystal panels cannot be called ideal. To improve color rendering, increase contrast and ensure uniformity of illumination, the professional NEC Reference 21 uses diode backlighting. This monitor costs about $6,000 and for now it can be considered more of a printing equipment than a computer peripheral. But we know many examples when professional technology"go down" to amateurs.
Many large companies(Sanyo, Samsung, Epson) are developing screens based on OLED - organic crystals. The crystals themselves emit light when voltage is applied, these screens are extremely economical, bright and contrasting. But so far they are used only in small portable equipment due to the high cost and technical problems associated with durability and reproduction of certain colors. In the very distant future, completely new technologies that only experts have heard of now may appear, and the screen can be rolled into a tube or glued to the wall. Or maybe there will be no monitors in our usual sense? Or maybe everyone will switch to projectors? And almost any surface can be used as a screen. A tempting prospect.