Home Other Which matrix is better: IPS or TN-TFT? Which screen type should you choose: IPS or TFT? Is IPS or TFT display better? Display type tft ips what.

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Which matrix is better: IPS or TN-TFT? Which screen type should you choose: IPS or TFT? Is IPS or TFT display better? Display type tft ips what.

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 the charges of multiple LEDs from merging. Therefore, today Thin Film Transistor technology has become the standard for LCD screen production. What other advantages does it have?

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).
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.
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.
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.

Going through the technical descriptions of modern smartphones, we often see the abbreviations TFT or IPS in the display column.

TFT is a technology in which the crystals in the display are arranged in a spiral and at the maximum possible voltage, they rotate so that the screen shows black, if there is no voltage we will see white. Typically used in budget models, for example. Such displays cannot produce perfect blacks; the output is dark gray.

IPS is the same TFT, but improved

IPS displays do not have any spirals; this is a more expensive technology that is used in high-end smartphones, for example in or. Recently, budget smartphones that use an IPS screen have become increasingly common; these can be classified as or, they belong to the middle price category.

Simply put, IPS technology is an improved TFT, which displays black colors much better and makes the picture on the display more contrasty than in TFT screens. IPS screens work a little slower, however, the user does not notice this and this feature can only be revealed as a result of technological tests.

The use of TFT displays seems to be a higher priority in simple phones that a person buys to make calls, and not to sit in contact, here is another example of a dialer. The advantage lies in much lower power consumption than IPS displays. But a modern smartphone with a simple TFT display is becoming increasingly rare.

Don’t be surprised if you see the abbreviation TFT in the technical specifications of an expensive smartphone; it could be an IPS display, because IPS is a type of TFT, like AMOLED and Super AMOLED.

Derivative technologies have emerged from IPS and TFT. For IPS these are Super IPS and UA-IPS - basically the same thing, but with some improvements. For TFT it is TN+Film - capable of better color reproduction.

The difference between image quality in IPS and just TFT is striking. When tilted, a regular TFT without IPS technology turns black so that it is no longer possible to make out anything, but with IPS it holds on as if nothing had happened, it’s amazing what technology has come to)

Abbreviations are usually used to indicate characteristics or specifics. In this case, there is terrible confusion regarding the comparison of IPS and TFT screens, because IPS technology (matrix) is a type of TFT matrix and nothing more. It is impossible to compare these 2 technologies with each other.

BUT! There is TN-TFT technology - you can make a choice and compare between it and IPS. Therefore, when we talk about which screen is better: IPS or TFT, we mean TFT screens in any case, but made on the basis of different technologies: TN and IPS.

Briefly about TN-TFT and IPS

TN-TFT is the technology on which the LCD screen matrix is made. Here the crystals, when no voltage is applied to their cells, “look” at each other at an angle of 90 degrees. They are arranged in a spiral, and when voltage is applied to them, they rotate in such a way as to form the desired color.

IPS – this technology is different in that here the crystals are arranged parallel to each other in a single plane of the screen (in the first case, spirally). This is all complicated... in practice, the difference between TN and IPS screens is that IPS displays blacks perfectly, resulting in sharper and richer images.

As for TN-TFT, the color rendering quality of this matrix does not inspire confidence. Here, each pixel can have its own hue, hence the colors are distorted. IPS matrices show the picture much better and also handle colors more carefully. IPS also allows you to observe what is happening on the screen from a large angle. If you look at a TN-TFT screen from the same angle, the colors will be distorted so much that it will be difficult to make out the picture.

Advantages of TN

However, TN-TFT matrices have their own advantages. The main one is the lower pixel response speed. IPS needs more time to rotate the entire array of parallel crystals to the desired angle. Therefore, if we are talking about choosing a monitor for games or for displaying dynamic scenes, when drawing speed is very important, then it is best to choose screens based on TN-TFT technology.

On the other hand, during normal work with a PC, it is impossible to notice the difference in pixel response time. It is only visible when viewing dynamic scenes, which often happens in action films and video games.

Another plus is low energy consumption. IPS matrices are energy-intensive, because They need a lot of voltage to rotate the crystal array. Consequently, TFT-based screens are better suited for mobile gadgets where the issue of saving battery power is an urgent issue.

And one more thing - TN-TFT matrices are cheap. You cannot find a monitor today (not counting used or CRT models) that is cheaper than a model based on TN technology. Any budget electronics device with a screen will definitely use a TN-TFT matrix.

So, which screen is better:TFT orIPS:

IPS is less responsive due to longer response time (bad for games and action scenes);
IPS guarantees almost perfect color reproduction and contrast;
IPS has a wider viewing angle;
IPS are energy-hungry and consume more electricity;
They are also more expensive, while TN-TFT are cheap.

That, in principle, is the whole difference between these matrices. If you take into account all the advantages and disadvantages, then, of course, it is easy to come to a specific conclusion: IPS screens are much better.

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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 an IPS panel will not be white, as for a 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.

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.

TFT (Thin film transistor) is translated from English as thin film transistor. So TFT is a type of liquid crystal display that uses an active matrix controlled by these transistors themselves. Such elements are made of thin film, the thickness of which is approximately 0.1 microns.

In addition to their small size, TFT displays are fast. They have high contrast and image clarity, as well as a good viewing angle. These displays do not have screen flickering, so your eyes don't get tired as much. TFT displays also do not have beam focusing defects, interference from magnetic fields, or problems with image quality and clarity. The energy consumption of such displays is 90% determined by the power of the LED backlight matrix or backlight lamps. Compared to the same CRTs, the energy consumption of TFT displays is approximately five times lower.

All these benefits exist because this technology refreshes the image at a higher frequency. This is because the display dots are controlled by individual thin film transistors. The number of such elements in TFT displays is three times greater than the number of pixels. That is, there are three color transistors per point, which correspond to the primary RGB colors - red, green and blue. For example, in a display with a resolution of 1280 by 1024 pixels, the number of transistors will be three times larger, namely 3840x1024. This is precisely the basic operating principle of TFT technology.

Disadvantages of TFT matrices

TFT displays, unlike CRTs, can show a clear image in only one “native” resolution. Other resolutions are achieved by interpolation. Another significant disadvantage is the strong dependence of contrast on the viewing angle. In fact, if you look at such displays from the side, top or bottom, the image will be greatly distorted. This problem never existed in CRT displays.

In addition, transistors on any pixel can fail, resulting in dead pixels. Such points, as a rule, cannot be repaired. And it turns out that somewhere in the middle of the screen (or in the corner) there may be a small but noticeable dot, which is very annoying while working at the computer. Also, for TFT displays, the matrix is not protected by glass, and irreversible degradation is possible if the display is pressed hard.