Vertical viewing angle of the va matrix on a TV. How to choose a TV for your home: types of matrices

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Hello, dear habra community.

After studying the hardware, I clarified some points.

I Type of image formation.

Today there are 3 types of image formation on modern TVs:

1 LCD.

The most common type of TV. Images in such TVs are produced using polarized light, several filters and controlled liquid crystals.

1.1 Types of LCD TV backlights.

Since the image that we see on the LCD TV screen is obtained as a result of the passage of polarized light from the backlight source, it is necessary to identify 2 types of backlight:
a) CCFL, also known as cold cathode. A subtype of thin fluorescent lamps located behind the matrix.
Advantages: uniform illumination.
Disadvantages: large thickness, power consumption, inability to control the backlight locally.
b) LED - light emitting diodes. Currently, cold cathode TVs have almost completely replaced them.
Advantages: it is possible to make very thin TVs, low power consumption, the ability to locally control the backlight.

A few words need to be said about local backlight control and the LED backlight division. LED backlighting is divided into 2 types: edge lighting (aka EDGE-LED, when the LEDs are located at the edges of the matrix, their light hits the diffuser and is scattered) and carpet (Full HD LED, LED Pro). Since LCD pixels themselves do not emit light, they require a backlight (as discussed above), which is always on. Closed crystals still transmit light, so it is impossible to achieve low black levels (the lower the better) and contrast transitions in edge-lit systems. The highest level TVs use carpet backlighting (when the LEDs are located directly behind the matrix). This makes it possible to improve backlight uniformity and implement segmented backlight control, where individual diodes responsible for areas on the screen can dim the brightness depending on the scene on the screen. In fact, only 2 series have carpet lighting - the Philips 9th series and the Sony 9th series. LG's 9 Series also has carpet lighting, but its implementation is worse than the edge lighting of competitive solutions.

Illumination unevenness.

Due to the fact that the LEDs are located with a certain periodicity (scattering and many other factors have their influence), in almost 100% of cases LCD TVs with LED backlighting have uneven illumination (clouding) - when areas that should remain black have a different gradation of gray.
The problem is partially solved by segmented LED backlight.

1.2 Types of matrices of LCD TVs with LED backlighting.

I will not go into details of image formation by different types of matrices, but will briefly describe their main advantages and disadvantages.
a) IPS(currently produced only by LG). Matrices that, in my opinion, are ideal for low and mid-level TV.
Advantages: large viewing angles.
Flaws: high black level (~0.16 nits), long response time.
Installed in LG TVs 3-9 series (that is, in fact, in all, without division into levels), Philips 4, 6 series, Panasonic of various variations and many others.
b) S-PVA(manufactured by Samsung). Matrices for TVs of higher classes.
Advantages: deeper black (0.05-0.1 nits depending on the backlight implementation).
Installed in Samsung TVs 7-8 series, Sony 7-8 series, Philips 7-8 series and some others.
c) UV²A(manufactured by Sharp). In my opinion, the most advanced type of matrices.
Advantages: the angles are larger than S-PVA (but smaller than IPS). Deepest black level (0.02 - 0.06 nits)
Flaws: Sharp doesn't produce them in sufficient quantities.
Installed in Philips 9-series TVs and top-end Sharp series.

2. Plasma.

There are a lot of myths and misconceptions associated with this word. Any uninformed salesman will definitely tell you that plasma is outdated. This is due to a set of stereotypes and problems that took place.
The image is formed by the glow of a phosphor under the influence of UV rays.
Each plasma cell is an independent light source, so the TV does not require a backlight. Previously, plasma TVs had a very large thickness and cell size, so they were very bulky and Full HD diagonals started from 50-60". Now the thickness of modern plasma TVs does not exceed 3-4 cm, and diagonals start from 42".

Plasma TVs do not have various types matrices with marketing names, but there are generations of panels (the most advanced is the 15th).

Now plasma has almost been replaced by LCD TVs and only 3 companies are engaged in its production: Panasonic, Samsung and LG (and only the first 2 have their own developments). This is due to unprofitable production, competition from LCD TVs and their popularization. But plasma holds the first positions in large diagonals.

3. OLED.

Organic LEDs. Something in between the first 2 technologies. The image is formed using self-emitting diodes that glow when exposed to electric current. As in plasma, each cell is an independent light source. So far there are only a few serial samples of such TVs at very high prices. LG and Samsung are developing in this area.

There are other types of TVs, such as laser projection TVs, but their development has ceased.

Briefly about the advantages and disadvantages of each technology:

LCD:
Advantages:
- relatively low production price, which allows manufacturers to receive fairly high profits and invest in production.
- Static imaging method (no dithering) is good for displaying images and photographs.
- Great for static images and not afraid of them.
- LCD TVs have high brightness and low power consumption
Flaws
- High black level (from 0.02 nits in a UV²A matrix with carpet backlighting to 0.2 nits in IPS).
- Long response time
- Lack of volume and depth of the image
- Dynamic resolution without artificial tricks 300 - 700 lines.

Plasma
Advantages
- Overall image depth. In general, when delivering high-quality content, the image on plasma is noticeably different from that on LCD: it has greater depth and color saturation, and has a pronounced volume effect.
- Low black level (0.008 nits on 2012 Panasonic models).
- They have dynamic resolution without artificial tricks of 1080 lines.
- Excellent for dynamic images (movies), they reveal high-quality content well.
- Virtually no response time.
- Freest viewing angles
Flaws
- Not at all suitable for connecting to a computer due to image retention
- Photos show worse (since gradations are obtained using dithering)
- High power consumption, not all models have high brightness.
- High production costs, low margins - it is becoming increasingly difficult for manufacturers to stay afloat.

OLED
The newest imaging technology in TVs. Self-emitting organic light-emitting diodes are used. Like plasma, these are self-emissive displays that do not require a backlight.
Now only a few production samples have been released at a price ten times higher than similar LCD and plasma TVs, but LG promises that in 3 years OLED TVs with similar LCD and plasma diagonals will cost 1.5 times more.
Advantages:
- low response time and high contrast, like plasma, since there are no mechanically rotating molecules and constant backlighting, as in LCD.
- efficiency
- wide viewing angles.
Flaws:
- various degradation of pixels over time (the same as with plasma, which leads to afterimages and pixel burnout). Now they are trying to compensate for this programmatically.
- Low service life: about 10,000 hours (for example, LCD - 60,000 hours, plasma - 100,000 thousand hours).

II Image characteristics

When choosing a new TV, I came to the conclusion that some image characteristics can be changed, others cannot.
Measured characteristics:
- Black level (MLL, Minimum luminescence level) - the black level that the TV shows when a signal of 0 is applied. [nit]
- Brightness is the brightness level that the TV shows when a 255 signal is supplied to it.
These 2 characteristics are measured together when a “chessboard” (ANSI method) is displayed on the TV - alternating black and white areas. The brightness of each area is calculated, the arithmetic average of the brightnesses of the black and white areas.
- Contrast. The difference between the arithmetic mean of black and white areas when black areas are taken as one.
ANSI contrast of IPS matrices is ~ 1000:1, S-PVA - 3500:1, UV²A - 5000:1, plasma - 12000:1.
- Color accuracy (DeltaE, deviation from the standard). The input signal is supplied, the output signal is measured. The greater the deviation, the less accurate the color rendition. It is believed that the naked eye is unable to detect DeltaE deviation< 3, а нулем обозначается идеальная цветопередача.
- Viewing angles. The smaller the viewing angle of the matrix, the more color is distorted. LCD S-PVA matrices have the smallest angles. The largest are plasma panels.
- Dynamic resolution. As you know, almost all TVs have a static resolution of 1080 lines (1920x1080 pixels), but dynamic resolution (what the TV shows when there is movement on the screen) is often different. It is for this purpose that backlight flickering, frame interpolation and other tricks are introduced into LCD TVs.

Subjective characteristics
These include the three-dimensionality of the image, which is formed by a combination of black level and color saturation, the “cinematic quality” of the image, and the effect of presence.

Thank you for your attention.
If the article seems interesting, in the next part I will write about the choice of diagonal, 3D types, their practical differences, image interpolation and try to debunk some myths.

Sergey Plotnikov,

Choosing a TV for yourself and your family is not an easy task. In addition to the luminaries of the industry, there are countless different companies on the market offering a variety of products. At the same time, a TV is a type of device that is purchased for a very long time. Therefore, it must have a high degree of reliability, rich functionality and good technical equipment, so that even after two or three years it can still be considered modern. This is what we will talk about in the first part of a series of materials devoted to choosing a TV for home use.

Choose good TV- a responsible occupation. After all, this particular device will help while away the time on cool evenings. It is the TV that will show how your favorite football team wins another victory. It is he who will tell about all the events that are happening in the world. Therefore, choosing a TV for your home must be approached with due responsibility.

In the first part of the material I will consider the main characteristics of modern TVs. We will talk about technologies for creating matrices, resolutions, marketing tricks of manufacturers, Smart capabilities of devices and much, much more. Therefore, I suggest not to be distracted and, as they say, to start right off the bat.

The main parameter is the diagonal

The main parameter of the TV that the buyer pays attention to is the diagonal. Not the matrix type, not the resolution, not the presence of 3D and Smart TV, but the screen diagonal. Of course, cost can also be equated to this parameter, however, as practice shows, these values ​​are very closely interrelated, because the larger the diagonal, the more expensive the TV.

There is a common myth that a large diagonal TV must be viewed at a very good distance. A decent distance is harmful to vision. This “theory” is so deeply rooted in the masses that when communicating with TV manufacturers, I constantly have to listen to complaints that people are afraid to purchase large panels.

SONY considers a parameter equal to or greater than 45 inches to be large. And Samsung is 50 inches.

In fact, when choosing a TV and calculating the distance from which you will look at it, you must first of all start not from the diagonal of the device, but from its resolution and the quality of the content being played. There are many studies on this topic. However, I propose to discard all speculation and fears and take as a basis the recommendations of THX, a reputable “player” in the film and television industry. The company, founded by George Lucas, recommends distancing yourself from the TV by the following distance:

I will only note that THX, for a certain display parameter, recommends such a distance that a person, as they say, does not run his eyes across the screen when viewing.

Note: 1 foot (feet) is equal to 0.3048 meters or 12 inches; 3.3 feet - 1 m.

It is quite obvious that the clearer the image, the shorter the distance required for comfortable viewing of the picture on TV.

Below is a table with popular resolutions. It unfolds to its full size.

Matrix production technologies

Types of matrices are perhaps the biggest springboard for all kinds of holivars. Which is better: LCD or plasma? What to choose: VA or IPS? Of course, each technology has its own characteristics, advantages and disadvantages, but in most cases it is necessary to build on the image quality of a particular TV model. That is why there is a golden rule: before purchasing the device, you must look and check it yourself.

Today, three technologies for producing matrices are considered relevant. Although you can say goodbye to one of them now. The fact is that many manufacturers of plasma panels are gradually beginning to abandon their production. Pioneer left the race a long time ago. Panasonic has not produced plasma since last year: “ Until recently, due to its excellent image quality, Panasonic plasma panels were highly valued and in strong demand around the world. However, due to the rapid and rapid changes in the business environment and the decline in demand for plasma panels in the flat screen market, it became clear that it would be difficult to continue the business, and the decision was made to cease production“- this was said in the official statement of the Japanese company.

This year, LG also announced its refusal to produce plasma TVs. Now the company will completely focus on the production of IPS and OLED. So from now on we can safely say that LCD is better than plasma. At least in terms of production and sales of goods.

It turns out that among the major players producing plasma, only Samsung remains.

As a matter of fact, LCD (aka LCD, liquid crystals) was, is and, most likely, will be the most common and popular technology for the production of televisions for the next few years. I see no point in talking in detail about the operating principle of this technology. It has existed for a long time and is well known to many. I will only note that the principle of constructing an image is based on the passage of polarized light from the backlight.

Today there are three popular types of LCD matrices:

• IPS. Decoding the abbreviation simultaneously explains the principle of operation of the technology: In-Plane Switching, that is, the liquid crystal molecules are located parallel to the screen plane. In turn, IPS comes in several types - AS-IPS, H-IPS, AH-IPS, E-IPS, P-IPS and S-IPS. Therefore, these matrices can be used both in very cheap TVs and in expensive ones. The image quality, unsurprisingly, will differ quite noticeably. A good IPS display has decent color rendering, high brightness, and large viewing angles. Among the disadvantages, it is worth noting the long response time, as well as a high black level.
• VA (MVA, PVA, S-PVA). The technology stands for vertical alignment. It is a compromise between TN and IPS. At the same time, it has a lower black level and high static contrast.
• UV 2 A. Quite a rare technology, promoted by the Sharp company. The matrix has larger viewing angles than, for example, VA, and also has a very deep black level.

IN Lately LCD matrices are evolving through the use of different types of backlights. Today they can be divided into two types: CCFL and LED. The first backlight variation (cold cathode) is present in older LCD TVs. The image is generated by fluorescent lamps located behind the matrix. This results in a uniformly illuminated picture, but CCFL TVs are thick and also have high power consumption. LED backlighting consists of light-emitting diodes. It is energy efficient and more compact. Therefore, it is more commercially profitable. In addition, it allows you to locally control the matrix backlight. Not surprisingly, there are several LED technologies:

• Edge lighting. It is also called EDGE-LED. In such illumination, as you might guess, the diodes are located at the edges. The light emitted from them hits the diffuser and is scattered across the entire surface of the screen. The main disadvantage of edge lighting is the high black level. The fact is that liquid crystals themselves do not emit light, so they always need a working backlight. However, they constantly miss it.
• Carpet lighting. There are various modifications: Direct LED, LED Pro, FHD LED. The LEDs are located directly behind the matrix. Due to this, it is possible to achieve uniform illumination of the screen. Moreover, many modern televisions equipped with control modules that allow only certain areas of the display to be illuminated. Based on carpet lighting, technologies have emerged that qualitatively reduce the black level.

OLED technology is the youngest and, therefore, innovative. However, like any other young development, it has a number of “sores” that prevent the rapid spread of devices among ordinary users. OLED stands for organic light-emitting diode - organic light-emitting diodes. The image is formed by self-emitting diodes under the influence of electric current. Therefore, OLED TVs do not need a backlight (the maximum brightness, meanwhile, can reach 100,000 cd/m2). The technology allows you to create very thin matrices with excellent color rendering parameters, brightness, contrast and black level. OLED can operate in harsh industrial environments, such as temperatures ranging from -40 to +70 degrees Celsius. Finally, the matrix has an almost complete absence of inertia.

But there are also tangible shortcomings. The first is the very high cost of production. However, every year OLED becomes noticeably cheaper. For example, last year the LG 55EA980V model cost 400,000 rubles. Now the updated version of the TV called 55EC9300 costs about 250,000 rubles. It is expected that next year it will be possible to purchase an OLED for less than 100,000 rubles. Still expensive, but not outrageously expensive.

In no case should you equate concepts such as “LED TV” and “LED TV.” The first is the type of matrix, which also does not have a backlight; the second is the type of LCD matrix backlight. Unfortunately, even very large chain stores of consumer electronics confuse these concepts.

The second significant disadvantage of OLED is the short service life of the matrix, as well as varying levels of pixel degradation. Thus, red and green diodes can boast a long life of 50-70 thousand hours of continuous operation, but blue - only 30 thousand hours. This unevenness may result in image distortion. But what is 30,000 hours of continuous operation? This is almost 3.5 years. If you consider that on average a TV works only 8 hours a day, then it turns out to be 10 years of stable operation. Is it a lot or a little - decide for yourself, dear readers.

It is no coincidence that I put plasma panels in third place. The reasons have been described above. Leading manufacturers are abandoning the production of these displays one after another. However, plasma can still be found on sale, and this product will be available at all kinds of flea markets for a very long time.

The image of plasma panels is formed due to the glow of the phosphor under the influence of ultraviolet rays. Each plasma cell is an independent light source. That is why this type of matrix does not require backlighting. This is why OLED is often compared to plasma rather than LCD.

Initially, plasma panels were bulky and consumed a lot of electricity. However, now there are very energy-efficient models on sale with a body thickness that does not exceed that of LED-backlit TVs.

The advantages of plasma are obvious - image depth, high dynamic resolution, low sensor response time and low black level. The disadvantages include burnout of plasma cells and the afterimage effect. The manufacturers have sorted out the first problem. At home, it is impossible to make the cell burn out. To do this, you need to leave the contrast image for several days. In addition, at the right time, the TV’s protection system will work. But the second problem really exists. It is enough to leave a static image for several hours, and after this time, its silhouette will remain on a black background. However, again after a couple of hours the afterimage will disappear. It is because of this that plasma is not recommended for use as an image output system for a personal computer.

Below is a table with the advantages and disadvantages of certain types of matrices. However, it is quite conditional. For example, modern LCDs have very good viewing angles. And the black level of well-calibrated TVs is not satisfactory.

Technology	Advantages	Flaws
	Cheap production	Slow matrix, long response time
	High image brightness	Low dynamic resolution
	Works well with a static image	Black levels are higher than competitors
	High contrast	Production costs are still very high
		Pixel degradation
	Wide viewing angles	Short service life
	Excellent color rendition
	The ability to create very thin TVs
	Image depth	Image retention effect
	High dynamic resolution	Poor display of static images
	Low black level	High power consumption
	Fast matrix, low response time	High production cost
	Wide viewing angles	Refusal of leading manufacturers from producing plasma TVs

So, we've sorted out the matrices. Now I propose to get acquainted with the main, in my opinion, characteristics of televisions:

• Brightness. Here additional formulations are unnecessary.
• Contrast. The difference between the arithmetic mean of white and black areas. In this case, the black area is taken as one. There is such a thing as ANSI contrast. This is when the measurement is made using a checkerboard, alternating between white and black areas. For example, for IPS this parameter is somewhere around 1000:1, for S-PVA - 3500:1, for plasma - 12000:1.
• Black level. The display shows black when the signal is 0 nits. Simply put, absolute black is zero brightness.
• Viewing angles. Everything is clear here too. The bigger, the better. Thus, modern matrices have viewing angles in both planes of 178 degrees.
• Color gamut. This is an area with specific colors that the display can reproduce. The smaller it is, the worse. There are a number of standards by which the “professional suitability” of a matrix is ​​determined. For example, our test lab uses sRGB to test laptops and monitors. To test TVs, we use the HDTV REC709 standard. There is also such a thing as color accuracy. This is the deviation between the signal that is given at the input and the signal that is received at the output. It is designated as DeltaE. A well calibrated TV should meet the DeltaE parameter< 3. Однако человеческий глаз не способен определить отклонение в этих пределах. Идеальная цветопередача — это ноль. То есть, что подали на вход, то и получили на выходе.

There are many more subjective characteristics of TV images. We'll talk about some of them further.

LCD panels could not appear without the invention of a substance that is in a liquid state, but has some properties of crystalline bodies. It just so happened that cyanophenyl (this is the correct name for this substance) was discovered even before picture tubes were invented. And for a very long time people did not know what to do with this substance, they closed it in a jar and put it on a shelf right up until the middle of the 20th century, when they remembered about it and began to make the first LCD (LCD) displays for watches, calculators and other undemanding to the image technology. Of course, they were monochrome.

Now how does it all work. We see the image on the screen thanks to the LCD matrix itself and the backlight, which illuminates this matrix from behind. The matrix ensures the passage of light through a pixel of the desired color, so we see an image from a large number of multi-colored pixels.

Just so you understand, not all matrices are equally useful. That is, they are also divided into types.

TN matrices were the first to appear - they have good time response (that is, small), but they are not all right with viewing angles and color. Then IPS matrices were developed - these are excellent matrices with the best color rendition, the picture on them is natural. At first they had disadvantages such as long response time and price, but gradually these disadvantages became less critical. An intermediate option is VA matrices. The latter have a good response time, good price and viewing angles are better than TN.

If you want to understand TVs well and be able to tell the buyer about it correctly, you need to be able to distinguish between types of matrices. First, lightly press on the matrix; if the image is distorted, it is a TN or VA matrix. And then look at the viewing angles; if you look at the matrix from the side at an acute angle, the image changes color - this is TN.

Surely this is a reasonable question. Which matrix is ​​better? Yes, none. For different purposes you need to choose different ones. If you are a gamer and it is important for you that objects on the screen move a little faster than the speed of light - you would be better suited TN, if you need an inexpensive TV, and you don’t care about the image quality at all - VA or TN. But if you need a monitor or TV with high-quality images, then this is IPS. Such matrices, by the way, are also more durable.

For example, LG TVs have IPS matrices throughout the entire model range, except for the most inexpensive models. You can poke your finger at the screens of other manufacturers and you will understand the potential of each TV.

Now let’s look at the tricky words “pixel”, “subpixel” and so on in order to understand the principle of operation of the LCD (LCD) matrix. As you know, a TV screen consists of a huge number of pixels - dots that change color depending on the image on the screen; a picture is formed from these dots. The more there are, the clearer the image. The pixel in turn is divided into subpixels - usually RGB (red, green, blue). Mixing these colors in a pixel allows you to produce the desired color.

Instead of a thousand words. This is what it looks like when zoomed inLCD (LCD) display.

And now, colleagues, look at the picture and observe those tricky processes that occur in the LCD matrix of your laptop when you read jokes on the Internet and watch videos about funny cats.

As you can see, the display is a complex sandwich consisting of several layers. All the most exciting things happen in the layer of liquid crystals. When voltage is applied to the electrodes, the molecules of liquid crystals line up in a certain way, and when there is no voltage, they don’t line up accordingly. The light from the backlight, which is located behind the matrix, can pass through the pixel and be highlighted in the desired color (remember RGB?), or it may not pass through without highlighting anything. In the picture you can see that if there is voltage, light does not pass through the pixel. These are all crystal molecules, they transform the light so that it does not pass through the matrix. If we talk in simple language, then between the person looking at the screen and the backlight there is a cunning and very technologically advanced light filter, which changes its properties with enormous speed. As a child, you probably watched filmstrips. The principle is similar.

You will need

• - matrix for replacement;
• - a set of screwdrivers with a special profile;
• - thin tweezers;
• - a thin metal plate.

Instructions

The most difficult thing when replacing a matrix is ​​to find a suitable analogue. Different manufacturers of LCD TVs may use the same matrix models, and therefore it is possible to determine the part code without disassembling the TV only from the specifications specified in the user manual, and even then not always. The best way to select a replacement - take a photo of the nameplates located on the back side of the broken matrix and use them to look for the corresponding part. It is not always possible to buy a new matrix, especially if the TV model is relatively new, and therefore you may need to visit stockists or purchase a TV of the same model with a whole screen, but with other types of damage.

To replace the matrix, you need to completely disassemble the TV case. It consists of front and rear halves, fastened together with screws or self-tapping screws located on the rear wall. After unscrewing the connecting elements, you need to place the TV with the screen up on a soft, flat surface and walk a thin metal plate around the perimeter, disconnecting the plastic latches. The front part of the case can serve as a decorative frame, but most often it is to it that the TV matrix is ​​attached using metal brackets or a frame. It should be removed after first disconnecting the power cable and signal cable.

Metal fasteners should first be installed on the new matrix, then the entire structure should be secured to the TV body. The sequence of assembly operations may differ depending on the design of the case; however, you must always remember the need to connect the signal cable and power wire. The functionality of the new screen must be checked before assembling the TV case. To do this, you will need to turn on the power and make sure that the matrix backlight is working and there are no burnt-out pixels, cracks or streaks on the surface of the screen. When the new display is found to be operational, you can finish assembling the case. If the TV does not display an image on the screen, you may need to coordinate a new matrix with the control module through the service menu. Manufacturers usually indicate how to do this in the instruction manual brochure. If you cannot find such information, you will have to seek help from a qualified adjuster.

If your laptop has problems with the image, stripes, ripples have appeared, or the screen has completely gone dark - the problem is in the matrix. You can try replacing it yourself.

You will need

• Screwdrivers, utility knife, new matrix.

Instructions

Remove the laptop screen by unscrewing the small bolts between the hinges of the cover. There can be quite a lot of them. Place small parts in a small box prepared in advance, otherwise there is a risk of not finding them later. Then unscrew the hinges themselves (put them in the box too) and separate the halves of the gadget from each other. You won't need the second half (where the keyboard, motherboard, processor, etc.) are, so set it aside.

Now detach the screen frame. Frames vary, so inspect yours carefully before you separate it. It can be secured with screws with rubber plugs and double-sided tape. In this case, lift and pull out the plugs, unscrew the bolts and only then pull the frame out of the fasteners, carefully prying it up. A regular plastic bank card can be a good help in your work. If the frame is simply glued, then peel it off using a utility knife. If the panel was only screwed on, then simply pry it off (with the same knife) and remove it.

The frame may be slightly deformed during disassembly, but this is not a big deal. Carefully set it aside without making any creases. When reassembled, it will snap into place and straighten out.

Unscrew the back wall of the screen. Then lift the matrix and disconnect the cables, having first peeled off the tape. The wider one goes to the matrix, and the narrower one goes to the webcam. Next, unscrew the frame (the antennas on it) that mount the screen.

To avoid dust getting inside the matrix, take it to the bathroom and turn on the shower for a few minutes. Now very carefully remove each film, plastic plate and frame, LED

Nowadays, thin TVs are present in many homes. They take up little space and deliver better images than their bulky, outdated counterparts.

TV manufacturers create various products based on the three most common technologies:

LCD

This technology is the most widespread in this moment. Why is she so popular? The fact is that the production of monitors using liquid crystals is relatively inexpensive. The lower price of LCD TVs compared to analogues attracts the largest number of buyers. Such TVs operate using backlighting (which can be different types), liquid crystals and light filters.

Plasma

Plasma TVs work completely differently when compared to LCDs. Unlike liquid crystal televisions, where there are pixels on the screens, in plasma televisions, image formation occurs due to the glow of gas-filled cells due to the influence of current on them. Each such cell glows independently - this means that such TVs do not need backlighting.

OLED

OLED technology could be called hybrid, because it contains the advantages that plasma and LCD technologies have separately. But this technology works completely differently. Screens developed using OLED technology contain organic light-emitting diodes, which themselves emit bright light. Consequently, these TVs do not require backlighting and still produce rich colors.

LED technology – what is it?

The vast majority of people who have heard about LED confuse it with OLED technology. In fact, these concepts have nothing in common.

LED is the backlight used in LCD technology. Recently, it has completely replaced the outdated CCFL backlight from the market.

There are two types of LED backlight:
EDGE-LED
This type of backlight is also called “edge” backlighting, because EDGE-LED consists of LEDs located at the edges of the matrix, the light from which is scattered across the entire area of ​​the monitor during operation. Backlighting is necessary because the pixels of an LCD TV do not produce light themselves. Contrast and black color on TVs with such backlighting are not the best high level, since even inactive crystals transmit light. In other words, the black areas on the TV also “glow.” The main thing is that EDGE-LED allows you to make really thin TVs, which will appeal to many people.

Full HD LED/LED PRO/Direct LED
This kind of lighting, which is called “carpet” lighting, is located not from the edges, but directly behind the matrix, evenly. This backlight option is used in the most expensive models of LCD TVs, because the cost of producing such devices is quite high. The advantages that such a technical solution provides are undeniable. This type of lighting allows you to achieve greater uniformity in the placement of the lighting. In addition, different LEDs can shine with different brightness, which allows you to achieve high quality contrast. Increased technical qualities mean an increase in the thickness of the TV.

Types of LED-backlit matrices in LCD TVs

The matrix of an LCD TV is usually a glass plate containing liquid crystals. They are placed between the matrix layers.

There are several types of matrices:
IPS


For LCD TVs, this type of matrix is ​​used only by LG. In principle, devices with these matrices do not have high image quality. IPS – matrices for TVs in the middle price segment. They have one advantage - the image on TVs with this type of matrix will be clearly visible from different viewing angles. Among the disadvantages is the low response speed, that is, the time it takes for the pixel to change its brightness. This affects the TV image, and with low response rates the picture will be “blurred”. Another disadvantage is that the black color is too “bright”.

S-PVA

More expensive TVs are equipped with an S-PVA matrix, which provides deep black color. But at the same time, this technology loses in color rendering quality and viewing angles compared to IPS. Present S-PVA matrix in TVs produced by Samsung, Sony, Philips. TVs with S-PVA are less popular.

U²VA
This type of matrix is ​​the most technologically advanced in terms of image quality. The viewing angles of this matrix are quite good, but less than in S-PVA. The depth of black color is the best among analogues. This matrix is ​​installed in expensive Sharp and Philips TV models.

Which TV to choose

Many people, faced with the widest range of LCD TVs with LED backlight, are wondering – which device is worth buying? When buying a TV, the first thing you need to think about is the size of the room where it will be located - and choose the diagonal relative to the size of the room. LED TVs come in different sizes, the largest of which can reach 90 inches, such as the Sharp AQUOS LC-90LE757LED.

But you need to understand that you cannot install such a large device in the kitchen. For large TVs, it is advisable to allocate specially equipped rooms for this purpose. Medium-sized TVs can be installed, for example, in the bedroom or living room. Such devices include fairly high-quality representatives Samsung UE40H7000ATXUA, LG 32LB572V, as well as Philips 40PFT4319/12, shown below.

When choosing a TV, you should also pay attention to its contrast, color rendering, response and viewing angles. All these parameters depend on the type of backlight and matrix. Practice shows that the most optimal image quality is found in fairly expensive device models. If you can’t overpay, you can choose more simple model TV, because technology allows you to give even budget options“decent” indicators. We hope that our short article will help you in choosing the optimal device for your home.