What you need to know about matrices on TV?

At choosing a TV necessarily pops up the concept of a matrix. This is the structure of the thinnest transparent electrical conductors on which the screen image depends. What matrices exist, how they differ from each other, and how to accurately determine the type, we find out further.

What is a matrix in a TV?

The matrix in the TV is a system of thin transparent electrical conductors, which are also called electrodes. In this case, one part of the plane is formed by parallel horizontal conductors, and the other vertical. The planes are parallel to each other (opposite). Thus, a square-nested mesh or “matrix” is formed.

Matrixes for TVs are of three main types -

LCD, LED (both based on liquid crystals) and "plasma screen. The physical principles of operation of LCD TVs and "plasma" are different, although they have one purpose - to create an image on the screen. Since each type also implies its own varieties, each of them is worth considering separately.

LCD Matrix Technology

LCD technology is also called liquid crystal technology (LCD) and is by far the most popular. In fact, such a matrix is ​​a viscous fluid, the molecules of which can synchronously change their position under the action of external forces, in our case, an electric voltage. The optical properties of the liquid layer for different directions of the light also change, for example, from an opaque state to a transparent one.

Liquid crystals fill the entire space between the special alignment films, which are full-screen. At the intersection of the conductors, a miniature device is obtained - a cell. This is a section that will transmit or not transmit light, depending on the presence of electric potential on the nearest conductors.

Vertical color bars (filters) are located between the external screen and the LCD layer, while the colors alternate. Three adjacent multi-colored dots (cells) form one pixel. Thus, there are three conductors per pixel. All cells (and pixels made up of them) have the same size and shape. From three colors, you can combine any color, including white.

The matrix operation scheme is as follows:

Behind the matrix, at the rear wall, light sources are fixed - tube lamps with a “cold cathode”. When the TV is on, they are constantly lit. Their light penetrates through color filters onto the screen. In order for the light from the lamps to fall on the screen more evenly, rather than in stripes, a special plate is located between the lamps and the screen. In addition, a mirror film is fixed behind the lamps so that all the light is reflected towards the screen.

On an LCD TV, light may pass through a cell with liquid crystals, or it may not. This will depend on whether voltage is currently applied to the conductors crossing in this cell:

• if there is no voltage, the liquid crystals are initially rotated to a position in which the polarized light cannot penetrate the cell, therefore the result is that the corresponding color is absent in pixel
• if voltage is applied, the crystals get a transparent position, so the light passes through the color filter to the outside, colors the pixel and participates in the formation of the overall image.

Types of LCD TVs

The most common at the moment are three technologies for imaging using liquid crystals:

TN

Usually means short for "TN + film" ("Twisted Nematic"). Translated means "swirling nematic crystal + film." The molecules in the cells are twisted in a spiral. The matrix looks like this:

Technology Advantages:

• the shortest response time, that is, the picture on the screen is updated very quickly, without delays and vagueness;
• relatively inexpensive production, respectively, low final price;
• low power consumption, therefore, it is well suited for devices with limited power supply (battery).

Minuses:

• strong image distortion when viewed from the side (side, top or bottom) even with a slight deviation from the perpendicular (up to 150 degrees);
• poor color saturation due to incomplete rotation of the LCD molecules when exposed to current and, as a result, the light in the cells is partially scattered;
• the light emitted by the lamps partially penetrates outward, which makes the screen gray even in the absence of a video signal and “closed” cells.

IPS or SFT

Matrix IPS (In-Plane Switching) or SFT (super fine TFT) means "switching in the plane." This is a development by Hitachi, later ported to Philips and LG.

The technology has two fundamental differences:

• electrically conductive paths do not cover the layer with liquid crystals on both sides, but are in contact with the LCD film from only one back side;
• the light through the internal screen and the LCD interlayer continuously falls on the external screen, however, the polarization of the light flux does not coincide with the polarization of the screen.

The matrix has the following scheme:

Positive features:

• viewing angle - maximum (of all available technologies);
• undeniably the best color rendering quality, which allowed us to provide real 24 bits of RGB standard depth (8 per channel) before anyone else.

Negative features:

• Significantly longer response time compared to other cell designs;
• highest price;
• relatively larger (compared to TN and VA) cell and pixel sizes, which can be especially noticeable on small screens, but this does not prevent the use of IPS screens even for mobile manufacturers phones.

VA (MVA, PVA)

It stands for Vertical Alignment, which means vertical alignment. The developer is Fujitsu. In contrast to the previous technology, twisted structures of molecules are not formed in the LC interlayer. In the absence of an electric field, the molecules occupy a position strictly perpendicular to the external filter.

Thus, polarized light does not extend beyond the boundaries of the LCD interlayer. When a potential occurs, the molecules rotate 90 degrees, providing illumination of the filters. The matrix has the following scheme:

Advantages of technology:

• clear black color and, as a result, high contrast;
• saturated colors.

Disadvantages:

• color distortion of shadows with a perpendicular view of the screen and at a slight angle;
• the expressiveness of colors is sharply weakened when viewed from the side.

Based on the ideas of VA, MVA technology has incorporated a part of the ideas of the parallel IPS technology, which allowed to seriously improve image quality without significantly increasing the price.

LED matrixes for TVs

LED technology (light-emitting diode) differs from the LCD unprincipled, but only in the principle of creating a luminous flux. In LED-matrices, instead of “cold glow” backlight lamps, a whole network of LEDs is used. During image formation, some of the LEDs may turn off, providing a deeper black color.

LED matrix technology may vary:

• In the most low-cost versions of television matrices, light sources are located across the entire plane of the screen. This is a “DIRECT” technology.
• Some modern models use side-lighting LEDs located around the screen. This is the so-called EDGE technology. With their help, it is impossible to completely darken areas close to the center of the screen, but the dimensions of the device are much smaller.

Design feature gives TVs with LED-matrix such advantages:

1. Unattainable for conventional LCD-matrices brightness, saturation and contrast of the image. The black color on the LED is really thick, impenetrable black. If the LEDs do not light, then there can be no other colors besides black.
2. Much smaller linear dimensions of the device. Televisions with ultra-slim housings that manufacturers love to brag about are created exclusively with LED matrices;
3. There are no backlight lamps that can fail and thereby violate the brightness and uniformity of the image. Even with the failure of a significant part of the individual LED-LEDs, the TV remains in working condition.
4. Economical energy consumption - up to 40% less than traditional LCD TVs;

LCD TV matrix malfunction

The main malfunction of TV matrices is disabling LCD cells, which leads to the failure of the entire pixel (or group of pixels). This is an irreversible phenomenon that cannot be repaired. Matrices are practically not repaired - usually they are simply replaced. This is a complicated and expensive operation, so do not try repair or change the matrix at home.

The cause of the malfunction may be:

• mechanical damage - hitting it with a hard object or falling from a height will not make the TV image better.

• penetration of conductive liquid (water) into the electronic circuitry of the matrix (the situation is especially harmful and dangerous when water enters working TV, because this is fraught with failure of not only part of the cells on the screen, but also the entire matrix, and even the device whole);

• the lack of contact within the circuit, which occurs, as a rule, without the active participation of a person is either a factory defect or the degradation of metals and other materials of which matrix (such self-destruction occurs due to physical wear of the matrix elements, in particular, due to the cyclic change in their size and shape due to repeated heating-cooling).

According to the technological standards of manufacturers, a malfunction of 3-4 cells per screen is allowed, because there are millions of pixels in the screen, and several non-working points are almost invisible. However, when buying a TV, try to carefully examine the surface of the matrix and check it in different modes - off, on without a signal, completely bright white, and so on.

Plasma TVs

In plasma, the image is formed by the glow of the phosphor under the influence of ultraviolet rays. Each cell is a separate light source, so the TV does not need backlight. Modern models are produced by only three manufacturers - Panasonic, Samsung and LG.

Pluses of plasma:

• has a large depth and color saturation with a pronounced effect of the volume of a 2D image;

• reproduces a deep black color;

• displays dynamic pictures well, which is important in revealing high-quality content;
• virtually no response time is required;
• has free viewing angles.

Disadvantages of plasma:

• It has an afterimage, so it is not suitable for connecting to a computer;
• badly shows photos;
• consumes a lot of energy;
• has a high price with low margins - plasma manufacturers are becoming less and less.

How to determine the type of matrix in the TV?

The easiest ways to find out the type of matrix:

• carefully inspect the packaging (usually manufacturers indicate the type of matrix of the television apparatus on the box);
• refer to the inscriptions on the TV itself (as a rule, films are glued to the front panel indicating the applied technologies and capabilities);
• type the name and index in the search engine and find the characteristics of the device on the Internet.

However, if the type of matrix cannot be determined by these methods, you can try to do this by indirect signs:

• if the matrix has faulty areas (broken pixels), you can distinguish VA and IPS screens from them;
• on TVs with more advanced technology, the defective portion of the matrix does not light (black), and that TN, on the contrary, is always white, even when the entire screen should be black;

• in IPS matrices, when you lightly click on the screen, the image does not change in any way, unlike other types of matrices;
• when you look at the TN-screen, even at a slight angle, the display of colors changes dramatically.

Which matrices on TVs are better?

The choice of TV matrix depends on the personal preferences and capabilities of the buyer:

• If you want an LCD TV, but the tools do not allow it, TN is the best choice. It is also a good budget option for large screens used in waiting rooms and other places of mass gatherings.
• VA TV, It will be an excellent solution for viewers who prefer more quality at a lower price. For example, the MVA standard is the best-selling technical solution in the home sector. This is a compromise, synthesizing the main positive aspects of all technical ideas.
• For those who are accustomed to being satisfied only with the best, it is worth making a choice in favor of a TV with an IPS matrix. Currently, there are many varieties of such a design that allows you to get exactly what you need from the TV and minimize the small flaws of the technology. Also, this standard is great for large screens that require readability and clarity in any light, even in bright sunshine.

A TV with any LCD-matrix will be the right option if you intend to use the TV as a monitor, for example, to access the Internet or view images. This is due to the fact that such a matrix does not differ in memory effect, in which the screen “freezes” on the screen, which is what monitors need.

Should I abandon the plasma panels, which were previously very famous due to the highest contrast provided by the best display of black? In fact, plasma will be the best choice if the buyer has these requirements:

• View mostly HD content
• Watch TV in the dark or in dim light;
• arrange a home theater (plasma creates the effect of "volume" with excellent contrast transitions and has a large diagonal).

In an incredible number of diverse options for models of LCD TVs, it is easy to get lost. One of the main parameters of such devices is the matrix. After reviewing a brief overview of existing technologies, you can decide which is the most optimal, based on your financial capabilities and preferences.