TFT display: description, operating principle

In the year 2007, when buying another mobile phone, we evaluated its design, rarely paying attention to the functionality and especially the screen - color, not too small, and that’s great. Today, mobile devices can hardly be distinguished from each other, but the most important characteristic for many remains the screen and not only its diagonal size, but also matrix type. Let's see what's behind the terms TFT, TN, IPS, PLS, and how to choose a smartphone screen with the required characteristics.

Types of matrices

Currently, modern mobile devices use three technologies for producing matrices based on:

• liquid crystal display (LCD): TN+film And IPS;
• on organic light-emitting diodes (OLED) – AMOLED.

Let's start with TFT(thin-film transistor), which is a thin-film transistor used to control the operation of each subpixel. This technology is used in all of the above types of screens, including AMOLED, so comparing TFT and IPS is not always correct. The vast majority of TFT matrices use amorphous silicon, but TFTs on polycrystalline silicon (LTPS-TFTs) have also begun to appear, the advantage of which is reduced power consumption and higher pixel density (more than 500 ppi).

TN+film (TN)– the simplest and cheapest matrix used in mobile devices with small viewing angles, low contrast and low color accuracy. This type of matrix is ​​installed in the cheapest smartphones.

IPS (or SFT)– the most common type of matrix in modern mobile gadgets, which has wide viewing angles (up to 180 degrees), realistic color reproduction and provides the ability to create displays with a high pixel density. This type of matrices has several types, let’s consider the most popular ones:

• AH-IPS– from LG;
• PLS- from Samsung.

It makes no sense to talk about advantages relative to each other, since the matrices are identical in properties and characteristics. You can distinguish a cheap IPS matrix by eye by its characteristic properties:

• fading of the picture when the screen is tilted;
• low color accuracy: an image with oversaturated or very dull colors.

Standing apart from LCD are matrices created on the basis of organic light-emitting diodes (OLED). Mobile devices use a type of OLED technology - matrix AMOLED, demonstrating the deepest blacks, low power consumption and overly saturated colors. By the way, the life of AMOLED is limited, but modern organic LEDs are designed for at least three years of continuous operation.

Conclusion

The highest quality and brightest images are currently provided by AMOLED matrices, but if you are looking at a non-Samsung smartphone, I recommend an IPS screen. Mobile devices with a TN+film matrix are simply outdated technologically. I recommend not buying a smartphone with an AMOLED screen that has a pixel density of less than 300 ppi; this is due to the problem of subpixel patterns in this type of matrix.

Perspective matrix type

– the most promising displays based on quantum dot technology. A quantum dot is a microscopic piece of semiconductor in which quantum effects play an important role. QLED matrices in the future will have better color rendering, contrast, higher brightness and low power consumption.

The image is formed using individual elements, usually through a scanning system. Simple devices (electronic watches, phones, players, thermometers, etc.) can have a monochrome or 2-5 color display. The multicolor image is generated using 2008) in most desktop monitors based on TN (and some *VA) matrices, as well as in all laptop displays, matrices with 18-bit color (6 bits per channel) are used, 24-bit is emulated with flickering and dithering .

LCD monitor device

Subpixel of color LCD display

Each pixel of an LCD display consists of a layer of molecules between two transparent electrodes, and two polarizing filters, the planes of polarization of which are (usually) perpendicular. In the absence of liquid crystals, the light transmitted by the first filter is almost completely blocked by the second.

The surface of the electrodes in contact with the liquid crystals is specially treated to initially orient the molecules in one direction. In a TN matrix, these directions are mutually perpendicular, so the molecules, in the absence of tension, line up in a helical structure. This structure refracts light in such a way that the plane of its polarization rotates before the second filter, and light passes through it without loss. Apart from the absorption of half of the unpolarized light by the first filter, the cell can be considered transparent. If voltage is applied to the electrodes, the molecules tend to line up in the direction of the field, which distorts the screw structure. In this case, elastic forces counteract this, and when the voltage is turned off, the molecules return to their original position. With a sufficient field strength, almost all molecules become parallel, which leads to an opaque structure. By varying the voltage, you can control the degree of transparency. If a constant voltage is applied for a long time, the liquid crystal structure may degrade due to ion migration. To solve this problem, alternating current is used, or changing the polarity of the field each time the cell is addressed (the opacity of the structure does not depend on the polarity of the field). In the entire matrix, it is possible to control each of the cells individually, but as their number increases, this becomes difficult to achieve, as the number of required electrodes increases. Therefore, row and column addressing is used almost everywhere. The light passing through the cells can be natural - reflected from the substrate (in LCD displays without backlighting). But it is more often used; in addition to being independent of external lighting, it also stabilizes the properties of the resulting image. Thus, a full-fledged LCD monitor consists of electronics that processes the input video signal, an LCD matrix, a backlight module, a power supply and a housing. It is the combination of these components that determines the properties of the monitor as a whole, although some characteristics are more important than others.

LCD Monitor Specifications

The most important characteristics of LCD monitors:

• Resolution: Horizontal and vertical dimensions expressed in pixels. Unlike CRT monitors, LCDs have one, “native” physical resolution, the rest are achieved by interpolation.

Fragment of the LCD monitor matrix (0.78x0.78 mm), enlarged 46 times.

• Point size: the distance between the centers of adjacent pixels. Directly related to physical resolution.

• Screen aspect ratio (format): The ratio of width to height, for example: 5:4, 4:3, 5:3, 8:5, 16:9, 16:10.

• Apparent Diagonal: The size of the panel itself, measured diagonally. The area of ​​displays also depends on the format: a monitor with a 4:3 format has a larger area than one with a 16:9 format with the same diagonal.

• Contrast: the ratio of the brightness of the lightest and darkest points. Some monitors use an adaptive backlight level using additional lamps; the contrast figure given for them (the so-called dynamic) does not apply to a static image.

• Brightness: The amount of light emitted by a display, usually measured in candelas per square meter.

• Response Time: The minimum time it takes for a pixel to change its brightness. Measurement methods are controversial.

• Viewing angle: the angle at which the drop in contrast reaches a given value is calculated differently for different types of matrices and by different manufacturers, and often cannot be compared.

• Matrix type: the technology used to make the LCD display.

• Inputs: (eg DVI, HDMI, etc.).

Technologies

Clock with LCD display

LCD monitors were developed in 1963 at the David Sarnoff Research Center of RCA, Princeton, New Jersey.

The main technologies in the manufacture of LCD displays: TN+film, IPS and MVA. These technologies differ in the geometry of surfaces, polymer, control plate and front electrode. The purity and type of polymer with liquid crystal properties used in specific designs are of great importance.

Response time of LCD monitors designed using SXRD technology. Silicon X-tal Reflective Display - silicon reflective liquid crystal matrix), reduced to 5 ms. Sony, Sharp and Philips jointly developed PALC technology. Plasma Addressed Liquid Crystal - plasma control of liquid crystals), which combines the advantages of LCD (brightness and richness of colors, contrast) and plasma panels (large viewing angles horizontally, H, and vertically, V, high update speed). These displays use gas-discharge plasma cells as brightness control, and an LCD matrix is ​​used for color filtering. PALC technology allows each display pixel to be addressed individually, meaning unrivaled controllability and image quality.

TN+film (Twisted Nematic + film)

The “film” part in the technology name means an additional layer used to increase the viewing angle (approximately from 90° to 150°). Currently, the prefix “film” is often omitted, calling such matrices simply TN. Unfortunately, a way to improve the contrast and response time for TN panels has not yet been found, and the response time of this type of matrix is ​​currently one of the best, but the contrast level is not.

TN + film is the simplest technology.

The TN+ film matrix works like this: When no voltage is applied to the subpixels, the liquid crystals (and the polarized light they transmit) rotate 90° relative to each other in the horizontal plane in the space between the two plates. And since the polarization direction of the filter on the second plate makes an angle of 90° with the polarization direction of the filter on the first plate, light passes through it. If the red, green and blue sub-pixels are fully illuminated, a white dot will appear on the screen.

The advantages of the technology include the shortest response time among modern matrices, as well as low cost.

IPS (In-Plane Switching)

In-Plane Switching technology was developed by Hitachi and NEC and was intended to overcome the disadvantages of TN+ film. However, although IPS was able to increase the viewing angle to 170°, as well as high contrast and color reproduction, the response time remained at a low level.

At the moment, matrices made using IPS technology are the only LCD monitors that always transmit the full RGB color depth - 24 bits, 8 bits per channel. TN matrices are almost always 6-bit, as is the MVA part.

If no voltage is applied to the IPS matrix, the liquid crystal molecules do not rotate. The second filter is always turned perpendicular to the first, and no light passes through it. Therefore, the display of black color is close to ideal. If the transistor fails, the “broken” pixel for the IPS panel will not be white, as for the TN matrix, but black.

When a voltage is applied, the liquid crystal molecules rotate perpendicular to their initial position and transmit light.

IPS is now being supplanted by technology S-IPS(Super-IPS, Hitachi year), which inherits all the advantages of IPS technology while reducing response time. But, despite the fact that the color of S-IPS panels has approached conventional CRT monitors, contrast still remains a weak point. S-IPS is actively used in panels ranging in size from 20", LG.Philips, NEC remain the only manufacturers of panels using this technology.

AS-IPS- Advanced Super IPS technology (Advanced Super-IPS), was also developed by Hitachi Corporation in the year. The improvements mainly concerned the contrast level of conventional S-IPS panels, bringing it closer to the contrast of S-PVA panels. AS-IPS is also used as the name for LG.Philips monitors.

A-TW-IPS- Advanced True White IPS (Advanced IPS with true white), developed by LG.Philips for the corporation. The increased power of the electric field made it possible to achieve even greater viewing angles and brightness, as well as reduce the interpixel distance. AFFS-based displays are mainly used in tablet PCs, on matrices manufactured by Hitachi Displays.

*VA (Vertical Alignment)

MVA- Multi-domain Vertical Alignment. This technology was developed by Fujitsu as a compromise between TN and IPS technologies. Horizontal and vertical viewing angles for MVA matrices are 160° (on modern monitor models up to 176-178 degrees), and thanks to the use of acceleration technologies (RTC), these matrices are not far behind TN+Film in response time, but significantly exceed the characteristics of the latter in depth of colors and accuracy of their reproduction.

MVA is the successor to VA technology introduced in 1996 by Fujitsu. When the voltage is turned off, the liquid crystals of the VA matrix are aligned perpendicular to the second filter, that is, they do not transmit light. When voltage is applied, the crystals rotate 90° and a light dot appears on the screen. As in IPS matrices, pixels do not transmit light when there is no voltage, so when they fail they are visible as black dots.

The advantages of MVA technology are the deep black color and the absence of both a helical crystal structure and a double magnetic field.

Disadvantages of MVA compared to S-IPS: loss of details in shadows when viewed perpendicularly, dependence of the image color balance on the viewing angle, longer response time.

Analogues of MVA are technologies:

• PVA (Patterned Vertical Alignment) from Samsung.
• Super PVA from Samsung.
• Super MVA from CMO.

MVA/PVA matrices are considered a compromise between TN and IPS, both in cost and consumer qualities.

Advantages and Disadvantages

Image distortion on the LCD monitor at a wide viewing angle

Macro photograph of a typical LCD matrix. In the center you can see two defective subpixels (green and blue).

Currently, LCD monitors are the main, rapidly developing direction in monitor technology. Their advantages include: small size and weight compared to CRT. LCD monitors, unlike CRTs, do not have visible flicker, focusing and convergence defects, interference from magnetic fields, or problems with image geometry and clarity. The energy consumption of LCD monitors is 2-4 times less than that of CRT and plasma screens of comparable sizes. The energy consumption of LCD monitors is 95% determined by the power of the backlight lamps or LED backlight matrix. backlight- back light) LCD matrix. In many modern (2007) monitors, to adjust the screen brightness by the user, pulse-width modulation of the backlight lamps with a frequency of 150 to 400 or more Hertz is used. LED backlighting is primarily used in small displays, although in recent years it has been increasingly used in laptops and even desktop monitors. Despite the technical difficulties of its implementation, it also has obvious advantages over fluorescent lamps, for example, a wider emission spectrum, and therefore a wider color gamut.

On the other hand, LCD monitors also have some disadvantages, which are often fundamentally difficult to eliminate, for example:

• Unlike CRTs, they can display a clear image in only one (“standard”) resolution. The rest are achieved by interpolation with loss of clarity. Moreover, resolutions that are too low (for example 320x200) cannot be displayed on many monitors at all.
• Color gamut and color accuracy are lower than those of plasma panels and CRTs, respectively. Many monitors have irreparable unevenness in brightness transmission (stripes in gradients).
• Many LCD monitors have relatively low contrast and black depth. Increasing the actual contrast is often associated with simply increasing the brightness of the backlight, up to uncomfortable levels. The widely used glossy coating of the matrix only affects subjective contrast in ambient lighting conditions.
• Due to strict requirements for constant matrix thickness, there is a problem of uneven color (backlight unevenness).
• The actual image change speed also remains lower than that of CRT and plasma displays. Overdrive technology solves the speed problem only partially.
• The dependence of contrast on viewing angle still remains a significant disadvantage of the technology.
• Mass produced LCD monitors are more vulnerable than CRTs. The matrix unprotected by glass is especially sensitive. If pressed hard, irreversible degradation may occur. There is also the problem of defective pixels.
• Contrary to popular belief, LCD monitor pixels degrade, although the rate of degradation is the slowest of any display technology.

OLED displays are often considered a promising technology that can replace LCD monitors. On the other hand, this technology has encountered difficulties in mass production, especially for large-diagonal matrices.

See also

• Visible screen area
• Anti-glare coating
• en:Backlight

Links

• Information about fluorescent lamps used to backlight the LCD matrix
• Liquid crystal displays (TN + film, IPS, MVA, PVA technologies)

Literature

• Artamonov O. Parameters of modern LCD monitors
• Mukhin I.A. How to choose an LCD monitor? . "Computer Business Market", No. 4 (292), January 2005, pp. 284-291.
• Mukhin I. A. Development of liquid crystal monitors. “BROADCASTING Television and radio broadcasting”: part 1 - No. 2(46) March 2005, p.55-56; Part 2 - No. 4(48) June-July 2005, pp. 71-73.
• Mukhin I. A. Modern flat-panel display devices."BROADCASTING Television and Radio Broadcasting": No. 1(37), January-February 2004, p.43-47.
• Mukhin I. A., Ukrainsky O. V. Methods for improving the quality of television images reproduced by liquid crystal panels. Materials of the report at the scientific and technical conference “Modern Television”, Moscow, March 2006.

When choosing a monitor, many users are faced with the question: which is better PLS or IPS.

These two technologies have existed for quite a long time and both show themselves quite well.

If you look at various articles on the Internet, they either write that everyone must decide for themselves what is better, or they do not give an answer to the question posed at all.

Actually, these articles make no sense at all. After all, they do not help users in any way.

Therefore, we will analyze in which cases it is better to choose PLS or IPS and give advice that will help you make the right choice. Let's start with the theory.

What is IPS

It’s worth saying right away that at the moment it is the two options under consideration that are the leaders in the technology market.

And not every specialist will be able to say which technology is better and what advantages each of them has.

So, the word IPS itself stands for In-Plane-Switching (literally “in-site switching”).

This abbreviation also stands for Super Fine TFT (“super thin TFT”). TFT, in turn, stands for Thin Film Transistor.

To put it simply, TFT is a technology for displaying images on a computer, which is based on an active matrix.

Quite difficult.

Nothing. Let's figure it out now!

So, in TFT technology, the molecules of liquid crystals are controlled using thin-film transistors, this means “active matrix”.

IPS is exactly the same, only the electrodes in monitors with this technology are on the same plane with liquid crystal molecules, which are parallel to the plane.

All this can be clearly seen in Figure 1. There, in fact, displays with both technologies are shown.

First there is a vertical filter, then transparent electrodes, after them liquid crystal molecules (blue sticks, they interest us most), then a horizontal filter, a color filter and the screen itself.

Rice. No. 1. TFT and IPS screens

The only difference between these technologies is that the LC molecules in TFT are not located in parallel, but in IPS they are in parallel.

Thanks to this, they can quickly change the viewing angle (specifically, here it is 178 degrees) and give a better picture (in IPS).

And also due to this solution, the brightness and contrast of the image on the screen has significantly increased.

Is it clear now?

If not, write your questions in the comments. We will definitely answer them.

IPS technology was created in 1996. Among its advantages, it is worth noting the absence of the so-called “excitement,” that is, an incorrect reaction to touch.

It also has excellent color rendition. Quite a lot of companies produce monitors using this technology, including NEC, Dell, Chimei and even.

What is PLS

For a very long time, the manufacturer did not say anything at all about its brainchild, and many experts put forward various assumptions regarding the characteristics of PLS.

Actually, even now this technology is shrouded in a lot of secrets. But we will still find the truth!

PLS was released in 2010 as an alternative to the aforementioned IPS.

This abbreviation stands for Plane To Line Switching (that is, “switching between lines”).

Let us recall that IPS is In-Plane-Switching, that is, “switching between lines.” This refers to switching in a plane.

And above we said that in this technology, liquid crystal molecules quickly become flat and due to this, a better viewing angle and other characteristics are achieved.

So, in PLS everything happens exactly the same, but faster. Figure 2 shows all this clearly.

Rice. No. 2. PLS and IPS work

In this figure, at the top there is the screen itself, then the crystals, that is, the same liquid crystal molecules that were indicated by blue sticks in figure No. 1.

The electrode is shown below. On the left in both cases their location is shown in the off state (when the crystals do not move), and on the right - when they are on.

The principle of operation is the same - when the crystals begin to work, they begin to move, while initially they are located parallel to each other.

But, as we see in Figure No. 2, these crystals quickly acquire the desired shape - the one that is necessary for the maximum.

Over a certain period of time, the molecules in the IPS monitor do not become perpendicular, but in the PLS they do.

That is, in both technologies everything is the same, but in PLS everything happens faster.

Hence the intermediate conclusion - PLS works faster and, in theory, this particular technology could be considered the best in our comparison.

But it is too early to draw final conclusions.

This is interesting: Samsung filed a lawsuit against LG several years ago. It claimed that the AH-IPS technology used by LG is a modification of PLS ​​technology. From this we can conclude that PLS is a type of IPS, and the developer himself admitted this. Actually, this was confirmed and we are a little higher.

Which is better PLS or IPS? How to choose a good screen - guide

What if I don't understand anything?

In this case, the video at the end of this article will help you. It clearly shows a cross-section of TFT and IPS monitors.

You will be able to see how it all works and understand that in PLS everything happens exactly the same, but faster than in IPS.

Now we can move on to further comparison of technologies.

Expert opinions

On some sites you can find information about an independent study of PLS ​​and IPS.

Experts compared these technologies under a microscope. It is written that in the end they did not find any differences.

Other experts write that it is still better to buy PLS, but do not really explain why.

Among all the statements of experts, there are several main points that can be observed in almost all opinions.

These points are as follows:

• Monitors with PLS matrices are the most expensive on the market. The cheapest option is TN, but such monitors are inferior in all respects to both IPS and PLS. So, most experts agree that this is very justified, because the picture is better displayed on PLS;
• Monitors with a PLS matrix are best suited for performing all kinds of design and engineering tasks. This technique will also cope perfectly with the work of professional photographers. Again, from this we can conclude that PLS does a better job of rendering colors and providing sufficient image clarity;
• According to experts, PLS monitors are virtually free from problems such as glare and flicker. They came to this conclusion during testing;
• Ophthalmologists say that PLS will be much better perceived by the eyes. Moreover, your eyes will find it much easier to look at PLS all day than IPS.

In general, from all this we again draw the same conclusion that we already made earlier. PLS is a little better than IPS. And this opinion is confirmed by most experts.

Which is better PLS or IPS? How to choose a good screen - guide

Which is better PLS or IPS? How to choose a good screen - guide

Our comparison

Now let’s move on to the final comparison, which will answer the question posed at the very beginning.

The same experts identify a number of characteristics by which different ones need to be compared.

We are talking about indicators such as light sensitivity, response speed (meaning the transition from gray to gray), quality (pixel density without losing other characteristics) and saturation.

We will use them to evaluate the two technologies.

Table 1. Comparison of IPS and PLS according to some characteristics

Other characteristics, including richness and quality, are subjective and vary from person to person.

But from the above indicators it is clear that PLS has slightly higher characteristics.

Thus, we again confirm the conclusion that this technology performs better than IPS.

Rice. No. 3. The first comparison of monitors with IPS and PLS matrices.

There is a single “popular” criterion that allows you to accurately determine which is better – PLS or IPS.

This criterion is called “by eye”. In practice, this means that you just need to take and look at two adjacent monitors and visually determine where the picture is better.

Therefore, we will present several similar images, and everyone will be able to see for themselves where the image visually looks better.

Rice. No. 4. Second comparison of monitors with IPS and PLS matrices.

Rice. No. 5. The third comparison of monitors with IPS and PLS matrices.

Rice. No. 6. The fourth comparison of monitors with IPS and PLS matrices.

Rice. No. 7. Fifth comparison of monitors with IPS (left) and PLS (right) matrices.

It is visually clear that on all PLS samples the picture looks much better, more saturated, brighter, and so on.

We mentioned above that TN is the most inexpensive technology today and monitors using it, accordingly, also cost less than others.

After them in price come IPS, and then PLS. But, as we see, all this is not at all surprising, because the picture really looks much better.

Other characteristics in this case are also higher. Many experts advise buying with PLS matrices and Full HD resolution.

Then the image will really look just great!

It is impossible to say for sure whether this combination is the best on the market today, but it is definitely one of the best.

By the way, for comparison you can see what IPS and TN look like from an acute viewing angle.

Rice. No. 8. Comparison of monitors with IPS (left) and TN (right) matrices.

It is worth saying that Samsung created two technologies at once that are used in monitors and in / and were able to significantly outperform IPS.

We are talking about Super AMOLED screens that are found on mobile devices of this company.

Interestingly, Super AMOLED resolution is usually lower than IPS, but the picture is more saturated and bright.

But in the case of PLS ​​above, almost everything that can be, including resolution.

The general conclusion can be drawn that PLS is better than IPS.

Among other things, PLS has the following advantages:

• the ability to convey a very wide range of shades (in addition to primary colors);
• ability to support the entire sRGB range;
• lower energy consumption;
• viewing angles allow several people to see the picture comfortably at once;
• all kinds of distortions are absolutely excluded.

In general, IPS monitors are perfect for solving common home tasks, for example, watching movies and working in office programs.

But if you want to see a really rich and high-quality image, buy equipment with PLS.

This is especially true when you need to work with design/design programs.

Of course, their price will be higher, but it’s worth it!

Which is better PLS or IPS? How to choose a good screen - guide

What is amoled, super amoled, Lcd, Tft, Tft ips? Don't know? Look!

Which is better PLS or IPS? How to choose a good screen - guide

TFT technology is used to create displays for all kinds of electrical devices, including TVs, tablets, computer monitors, mobile phones, navigators, etc. Undoubtedly, the screen in such devices plays an important role, so before purchasing equipment and gadgets, it is worth understanding the intricacies of their manufacture. The design of the display determines the quality and clarity of the image, viewing angle, and color reproduction. In some cases, these parameters are of great importance.

Concept of TFT display

TFT LCD is a type of active matrix liquid crystal display. Each pixel of such displays is controlled by 1-4 thin film transistors (in English - Thin Film Transistor, abbreviated as TFT), which help to easily turn on / off the LEDs, creating a clearer, higher-quality image.

The TFT display has two glass substrates, inside of which there is a layer of liquid crystals. The front glass backing contains a color filter. The back substrate contains thin transistors arranged in columns and rows. Behind everything is a backlight.

Interesting to know: Each pixel is a small capacitor with a layer of liquid crystal sandwiched between transparent conductive layers of indium tin oxide. When the display turns on, the molecules in the liquid crystal layer bend at a certain angle and allow light to pass through. This creates the pixel we see. Depending on the angle of bending of liquid crystal molecules, one color or another appears. All pixels together form a picture.

A standard TFT monitor has 1.3 million pixels, each of which controls its own transistor. They consist of thin films of amorphous silicon deposited on glass using PECVD technology (this method is usually used to create microprocessors). Each element operates on a small charge, so the image is redrawn very quickly, the image is updated many times per second.

Is it worth buying equipment with TFT displays?

Displaying moving images on a large LCD display is challenging because it requires changing the state of a large number of liquid crystals in a fraction of a second. In passive matrix LCDs, transistors are located only at the top and left of the screen. They control entire rows and columns of pixels. In such devices, crosstalk can occur due to the fact that the signal sent to one pixel affects its “neighbors”. Because of this, we see slowdown or blurring of the picture.

TFT displays do not have this problem. Installing a control device in the form of a thin film transistor directly on the pixel prevents the blurring effect during video playback. The unidirectional current flow characteristic prevents charges from merging across multiple LEDs. Therefore, today Thin Film Transistor technology has become the standard for LCD screen production. What other advantages does it have?

1. TFT allows you to get a stable, fairly high-quality image with a good viewing angle. In this case, you can make a screen of different sizes with different resolutions (from a calculator or smart watch to a TV for the entire wall).
2. Such screens have bright backlighting, which is important for mobile phones and computers. Bright LED backlights provide greater adaptability and can be adjusted based on the user's visual preferences. Some devices have a function to automatically adjust the brightness level depending on the lighting.
3. The advantages of TFT over older CRT monitors are obvious. CRTs are bulky, dim and small. CRTs generate a large amount of heat, as well as electromagnetic radiation, which negatively affects vision. TFT matrices are safe in this regard.
4. TFT screens have a fairly competitive price, although this method is used to produce not only budget devices, but also professional, expensive equipment.

At first glance it looks tempting. However, before you buy, you need to know: there are several types of TFT displays and they have different characteristics.

Types of TFT displays, their advantages and disadvantages

Names such as TN, IPS and MVA are all TFT displays. It's easy to get confused by these names. Let's try to figure out how they differ, and what is better.

Tweeted Nematic (TN) + Film

This is a simpler, cheaper and faster option. The response time of the TFT TN screen matrix is ​​only 2-4 ms. They can display more frames per second, which is especially important when watching videos and playing video games.

However, TN-based devices have many disadvantages in terms of image quality:

• The viewing angle of a TN display is only 50-90°. This means that you can only get the full effect of graphics on a screen made using TFT TN technology by looking at it directly. If you look from the side, above or below, the picture will change its color;
• low contrast ratios (maximum 500:1) and a small range of colors. Such a device will not convey all colors;
• The blacks in TN screens are too bright and lack depth, and the whites are not bright enough, meaning that nothing will be visible in sunlight.

If you use the device for regular web browsing, office work or other daily tasks, then a display with TFT TN technology will suit your needs. It is also suitable for gamers, since the image transmission speed is still more important during gaming. But for business or graphics work that requires the highest levels of color and graphic accuracy, your best bet is to choose a display with IPS technology.

Super TFT (or IPS)

IPS TFT technology solves all the problems of TN screen. The main difference from TN panels is the direction of movement of the crystals. In IPS displays, they move parallel to the panel plane, rather than perpendicular to it. This change reduces light scattering in the matrix and allows for wider viewing angles (from 170°), a large color spectrum (up to 1 billion), and high contrast (1:1000). Blacks will be deeper and more refined.

However, IPS also has a drawback: the response time of such matrices is 10-20 ms, which is not enough for modern video games, although acceptable. AMOLED screens have even longer response times.

It is impossible to say which is better: IPS or TN TFT technology. Each of them has pros and cons, so you need to proceed from the purpose for which you are buying the device. IPS is widely used in high-end monitors aimed at professional graphic artists.

MVA

This technology is the most advanced - it combines the advantages of the two previous options. MVA displays have a wide viewing angle, excellent color and contrast, deep blacks and at the same time optimal response time.

If you compare displays with TFT IPS and SVA technology (a type of MVA), it will be difficult to choose the best option. Everyone has merits. SVA has only a slight difference in structure - in such a display the crystals are aligned vertically rather than horizontally. This affects their ability to transmit or block light, which determines the display's brightness level and black output. In SVA displays, these parameters are at their best, although this does not mean that IPS shows a bad picture. Compared to IPS, SVA has a smaller viewing angle.

Flaws

Thin film transistors are very sensitive to voltage fluctuations and mechanical stress. They can be easily damaged, resulting in the formation of “dead” pixels – dots without an image. However, AMOLED screens, which are now gaining popularity, are even more fragile. From a reboot or mechanical damage, they stop working completely.

Another small minus is the thickness of the TFT display. Due to the additional layer, it will be slightly thicker than the thickness of a plasma panel, regular LCD or AMOLED. However, the TFT screen is quite compact.

Another relative disadvantage of the technology is its higher energy consumption when compared to other types of screens. But again, TFT displays are economical enough for everyday use.

Good day.

When choosing a monitor, many users do not pay attention to the matrix manufacturing technology ( matrix is ​​the main part of any LCD monitor that forms the image), and, by the way, the quality of the picture on the screen greatly depends on it (and the price of the device too!).

By the way, many may argue that this is a trifle, and any modern laptop (for example) provides an excellent picture. But these same users, if you put them on two laptops with different matrices - will notice the difference in the picture with the naked eye (see Fig. 1)!

Since quite a lot of abbreviations have appeared recently (ADS, IPS, PLS, TN, TN+film, VA), it’s easy to get confused. In this article I want to describe a little each technology, its pros and cons (it will turn out to be something in the form of a small reference article, which will be very useful when choosing: a monitor, a laptop, etc.). So…

Rice. 1. Difference in the picture when the screen is rotated: TN matrix VS IPS matrix

Matrix TN, TN+film

Descriptions of technical issues are omitted; some terms are “interpreted” in their own words so that the article is understandable and accessible to an untrained user.

The most common type of matrix. When choosing inexpensive models of monitors, laptops, TVs, if you look at the advanced characteristics of the device you choose, you will probably see this matrix.

Pros:

1. very short response time: thanks to this, you will be able to watch a good picture in any dynamic games, films (and any scenes with a rapidly changing picture). By the way, on monitors with a long response time, the picture may begin to “float” (for example, many complain about the “floating” picture in games with a response time of more than 9 ms). For games, a response time of less than 6ms is generally desirable. In general, this parameter is very important and if you are buying a monitor for gaming, the TN+film option is one of the best solutions;
2. affordable price: this type of monitor is one of the most affordable.

Cons:

1. poor color rendering: Many people complain about not bright colors (especially after switching from monitors with a different type of matrix). By the way, some color distortion is also possible (therefore, if you need to select the color very carefully, then you should not choose this type of matrix);
2. small viewing angle: Probably many have noticed that if you approach the monitor from the side, then part of the picture is no longer visible, it is distorted and its color changes. Of course, TN+film technology has somewhat improved this point, but nevertheless the problem remains (although many may object to me: for example, on a laptop this is useful - no one sitting next to you will be able to see exactly your image on the screen);
3. high probability of dead pixels: Probably even many novice users have heard this statement. When a “broken” pixel appears, there will be a point on the monitor that will not display the picture - that is, there will just be a luminous point. If there are a lot of them, it will be impossible to work behind the monitor...

In general, monitors with this type of matrix are quite good (despite all their shortcomings). Suitable for most users who love dynamic movies and games. It’s also quite good to work with text on such monitors. For designers and those who need to see a very colorful and accurate picture, this type should not be recommended.

Matrix VA/MVA/PVA

(Analogues: Super PVA, Super MVA, ASV)

This technology (VA - vertical alignment in English) was developed and implemented by Fujitsu. Today, this type of matrix is ​​not very common, but nevertheless, it is in demand among some users.

Pros:

1. one of the best black color renditions: when looking at the monitor surface perpendicularly;
2. more quality colors(in general) compared to TN matrix;
3. enough good response time(quite comparable to a TN matrix, although inferior to it);

Cons:

1. higher price;
2. color distortion at a wide viewing angle (professional photographers and designers especially notice this);
3. it is possible that small details may “disappear” in the shadows (at a certain viewing angle).

Monitors with this matrix are a good solution (compromise) for those who are not satisfied with the color rendition of a TN monitor and who need a short response time. Those who need colors and picture quality choose an IPS matrix (more on that later in the article...).

IPS matrix

Varieties: S-IPS, H-IPS, UH-IPS, P-IPS, AH-IPS, IPS-ADS, etc.

This technology was developed by Hitachi. Monitors with this type of matrix are most often the most expensive on the market. I think there is no point in considering each type of matrix, but it is worth highlighting the main advantages.

Pros:

1. better color rendition compared to other types of matrices. The picture turns out “juicy” and bright. Many users say that when working on such a monitor, their eyes practically do not get tired (the statement is very controversial...);
2. largest viewing angle: even if you stand at an angle of 160-170 degrees. - the picture on the monitor will be just as bright, colorful and clear;
3. good contrast;
4. excellent black color.

Cons:

1. high price;
2. long response time (may not suit some fans of games and dynamic films).

Monitors with this matrix are ideal for all those who need a high-quality and bright picture. If you take a monitor with a short response time (less than 6-5 ms), then it will be quite comfortable to play on it. The main drawback is the high price...

Matrix PLS

This type of matrix was developed by Samsung (planned as an alternative to the ISP matrix). It has both its pros and cons...

Pros: Higher pixel density, high brightness, lower power consumption.

Cons: Low color gamut, lower contrast compared to IPS.

By the way, one last piece of advice. When choosing a monitor, pay attention not only to the technical specifications, but also to the manufacturer. I can’t name the best of them, but I recommend choosing a well-known brand: Samsung, Hitachi, LG, Proview, Sony, Dell, Philips, Acer.

On this note I end the article, good luck to everyone :)