What is led tv. LED TV Samsung: it's not just a TV...

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LED display backlighting is one of the many ways to use LEDs. It began to be used on an industrial scale since 2008. Today, LEDs are installed in the vast majority of liquid crystal (LCD) screens: TVs, monitors, and mobile devices.

Since 2008, LED backlighting has been actively improved and improved. In this article we’ll talk about what LED backlighting is, what it comes in, and how justified its implementation in electronics is.

A little theory

Just 10 years ago, the main light source in LCD screens was fluorescent lamps like CCFL, HCFL, which lost plasma TVs in terms of image quality. The advent of white SMD light-emitting diodes with high luminous efficiency, low power consumption and dimensions has radically changed the situation, resulting in the emergence of a new generation of monitors.

Stores began to actively offer LED TV, without explaining that only LED backlighting was used, and the screen still remained liquid crystal. Large-scale advertising campaigns and beautiful stories from consultants about the advantages of the LED option have contributed to a sharp increase in sales of LED TVs and monitors, thanks to which today they have complete superiority over other types of backlighting.

LED Backlight Types

With the invention of compact ultra-bright LEDs, manufacturers were faced with the question: “How to place them in order to simultaneously obtain a high-quality image and save money?” Several types have appeared in search of an answer LED backlight, among which there are two main ones:

end (Edge), also called side or edge;
matrix (Direct), assembled on wled or rgb led.

According to the method of controlling the glow, there are also two types of backlight: static and dynamic. In the first case, the brightness of all LEDs changes equally regardless of the image. In the second case, each LED or group individually interacts with the corresponding section of the LCD matrix.

Edge

LEDs in the side lighting are arranged in one of the following ways:

On the sides;
up and down;
along the perimeter.

The choice of one or another placement method depends on the screen size and production technology. This type of backlight uses only white LEDs. The light flux they emit passes through the diffuser and the light guide system, thus illuminating the entire screen.

This method has three important advantages that made it popular. Low cost achieved through minimum quantity LEDs used and simplicity of the control system. The ability to create ultra-thin monitor models with a remote power supply, which, due to advertising, have become very popular among buyers. Low energy consumption, which is impossible to achieve in other variations. By light edge characteristics the backlight occupies an average position and strongly depends on the build quality and the used element base. But in general, color rendition is comparable to CCFL technology. Edge-lit TV models cannot achieve high contrast images for two reasons. All LEDs shine with the same brightness, equally illuminating dark and light areas of the screen. Light guides, despite their well-thought-out design, are not able to ensure uniform distribution of light over the entire working surface.

Direct

The back (matrix) illumination is a matrix assembled from several lines with LEDs distributed over the entire area. This method ensures uniform illumination of the entire LCD panel, and most importantly allows for dynamic control. As a result, the developers managed to achieve high image contrast and rich black color.

Direct backlighting is implemented in two ways. The first, most common, is assembled using white LEDs or WLEDs, which are basically the same thing. It can be either static or dynamic, depending on the TV model.

The second suggests using instead of white - RGB LEDs. With their help, it is possible to adjust not only the brightness, but also set any color from the entire visible spectrum. Due to high speed switching LEDs perfectly process the supplied signal and keep up with the rapidly changing picture on the screen. RGB lighting is built only according to the dynamic principle.

Matrix-backlit displays feature excellent contrast and color rendition across the entire screen area. This is their main advantage, which is covered by several disadvantages, namely:

high price;
high power consumption comparable to CCFL technology;
The case thickness is more than one inch.

If one of the LEDs fails, the entire line goes out. This phenomenon will be reflected on the screen as a darkening of a certain area. It will not be possible to replace a burnt-out element with a similar one on your own, since it is almost impossible to find an exact copy with the same lens. As a result, the entire line must be replaced.

About health disadvantages

LED backlight itself, regardless of its implementation method, has several significant drawbacks that affect not the image quality, but the vision. First of all, this is a pulse-width modulation function. With its help, the user adjusts the brightness and, thereby, worsens his health. The essence of the problem is the flickering of LEDs with a frequency above 80 Hz, which manifests itself when the brightness is reduced. Such flickering is not visually detected by the human eye, but it continuously irritates the nerve endings, causing headaches and fatigue in the eyes.

While watching television this disadvantage does not cause much discomfort due to the large distance between the viewer and the screen, as well as low concentration of attention. But users of PCs and laptops with LED backlighting find themselves in a dead end situation. On the one hand, when the monitor brightness is 100%, the pulse width modulation (PWM) function is disabled, but the retina of the eye suffers greatly. On the other hand, lengthy work with documents on reduced brightness It’s more comfortable for the eyes, but now PWM adds negativity.

In addition, there are other shortcomings that impair vision, the manifestation of which to one degree or another depends on the display production technology. For example, increased radiation of LEDs in the region close to the ultraviolet spectrum.

Those who value their eyesight should opt for a professional series of monitors with CCFL lamps, which are still produced for working with images. They have a high color rendering index and cost less than RGB LED products.

Despite the presence of shortcomings, manufacturers electronic technology will not stop using LED backlighting in their devices, and large companies will continue to advertise so-called LED TV. Because marketing goals still have a high priority. We can only hope that in the near future mass production of monitors will be equipped with higher quality backlighting, operating at a frequency that is safe for the eyes.

What is LED TV backlighting?

Edge LED

If you disassemble the TV, then behind the liquid crystal matrix around the perimeter of the case you can see many diodes that look like small light bulbs - this means that the TV has side lighting. The diffuser makes the screen illuminated evenly, but the backlight cannot be adjusted.

Matrix backlight (LED Backlight)

It is carried out by groups of diodes of three colors located over the entire surface of the panel. This method of illumination allows you to adjust it in individual areas, which allows you to achieve better color rendition.

What does LED TV mean for the consumer?

It is believed that this type of TV has a number of advantages over a conventional LCD TV.

What are the differences between LED TVs?

TVs of this type have a more contrasting image;
the colors are very rich and natural;
LED TVs consume less energy;
The LED TV body is thinner;
TV is capable of displaying signal high definition;
Screen viewing angles are maximum.

TVs are equipped with a number of connectors for connecting various devices and are even able to connect to the Internet.

Characteristics of LED TVs

permission. The resolution of LED TVs can be: Full HD and HD Ready. Full HD - the most a high resolution;
sweep frequency. The scan frequency can be up to 960 Hz. More high frequency scans will be required for 3D TVs;
matte or glossy screen. Glossy finish There may be glare on the screen. On matte, the viewing angle is not so great;
. If you are going to watch 3D movies, then choose between two display technologies and two types of glasses: active and passive. Determine by viewing which type is more suitable for you, is not irritating, and is comfortable for the eyes.
smart function. Smart function will come in handy if you are going to go online. Choose a model with or without a built-in router.

So, you have made your decision and decided to purchase an LED TV. Where do we start choosing?

How to wipe LED TV?

In addition to all sorts of special liquids and wipes, which are available in abundance on store shelves, the TV is wiped with microfiber cloths. First slightly damp and immediately dry.

Using our tips, you will be able to choose the LED TV that best suits your needs and can save on features you don’t need.

IN Lately Many people are concerned about the question of what is an LED TV? These units have proven themselves well and managed to gain wide popularity. The cost of this is gradually decreasing, making them much more affordable. Not everyone understands what an LED TV is, so it’s worth understanding the principle of its operation and discussing the pros and cons associated with production technology.

Essentially, this device is a liquid crystal TV in which the screen is illuminated using LEDs. Earlier models of LCD TVs use cold cathode lamps. It is worth mentioning the advantages of using an LED matrix in the backlight. Manufacturers talk about a significant increase in image quality. There are a number of parameters that have a direct impact on how viewers perceive an image. These include brightness, contrast level, black depth and color rendering quality. In most cases, LED-backlit TVs are significantly ahead of their counterparts.

If we talk about what an LED TV is, then it’s worth saying that the mentioned feature is associated with design features By adjusting the glow level of the diodes, it is quite possible to achieve absolute control over the brightening or darkening of certain areas of the screen. When turned off, the LED does not create any glow, so a group of turned off diodes creates completely black areas. Thanks to the use of this technology, it is possible to achieve deep black color display, as well as excellent contrast levels. Overall color rendition also becomes significantly better, which has a positive effect on image quality. Thanks to the glow of LEDs, LCD LED TVs have high brightness screen. Using a diode matrix allows you to make most of the parameters that are responsible for outputting a high-quality image much better. The significant reduction in energy consumption is another major benefit.

Speaking about what an LED TV is, it is necessary to mention that harmful aerosols and mercury are not used in production, and this has a beneficial effect on B. Both single-color and three-color diodes can be used, which can significantly increase the number of displayed colors. It is common practice to use white LED backlights, which reduces the risk of image problems.

Manufactured using "local dimming" technology, which is responsible for local dimming. According to it, LEDs are controlled by groups consisting of several individual elements. Disadvantage similar technology is the possibility of poor uniformity appearing in the output image. Usually this is the appearance of bright spots in areas where the backlight is brightly turned on and dark spots where the backlight is completely turned off.

Without such backlighting, no LCD TV can operate normally, regardless of its brand. We'll tell you how to do it Led repair TV backlighting at home using the example of a device from Lg, and what you will need for this.

How can you tell if the backlight is broken? Let's assume that the problem with the LCD TV is as follows: it turns on from the remote control, but the screen does not light up (if your TV does not turn on even from the remote control, read about). When pointed at the display flashlight light(i.e. forced illumination is applied), then the image appears. Verdict - the ice driver or similar backlight does not work, perhaps due to the fact that the special lines with soldered LEDs have burned out. You need to disassemble the TV and visually inspect the parts to find a fault.

Attention! You can only open the case of an LCD TV if you have the skills to work with complex devices and a little experience, otherwise it’s better not to risk it.

Remove the back cover For any LG TV, this is not a difficult task, you just need to do everything carefully and without haste: disconnect the legs of the stand and unscrew the mount around the entire perimeter of the product. If the cover does not come off, it means there is a blocking bolt, you should not make any effort, you need to find it and unscrew it.

After removal back cover, check the output voltage.

If it is normal, we check it voltage ice backlight the screen itself. Its value is only 100V, which indicates a malfunction in the backlight of the LCD TV.

These TVs use a special LED set with lenses that are installed across the entire screen area to provide clear illumination. To get to them and repair the LG TV backlight, you must first remove the matrix.

Disassembling the product

The TV has three main boards - main, T-con and power supply, all of which are clearly visible in the photo.

Removing and disassembling the matrix do it yourself - the work is very painstaking, one careless movement, and you can buy a new TV, so without experience it is better not to undertake repairs. Experts highlight the following main points when disassembling the matrix:

it is necessary to prepare a work area and two tables on which to lay matrices and scattering films;
Before starting this work, you should thoroughly wash your hands so as not to accidentally leave traces of dirty fingers on the filters and the matrix itself - this can harm the quality of the image later;
Special attention should be paid to decoders - one inaccurate movement can lead to a break in the cable.

Subsequent dismantling is carried out in several stages.

Troubleshooting

Now the actual repair of the LED backlight of the TV begins: to do this, you need to carefully unclip all the latches along the contour, remove the plastic frame and remove the diffusing films to expose the LEDs.

U different models LG TVs will have their own set of LED backlights: for LG 32LN541U there are three rows of 7 LEDs, and for LG 32LB582V there are three rows of 6 LEDs.

In all TVs that use such backlighting, the LEDs are connected in series, so if one of them burns out, the entire system stops working. If the LED driver is faulty, then no voltage is supplied to the entire system, and when one of the LEDs burns out, then the voltage flows, but all the efforts of the device to illuminate the system are in vain: even if you supply 200 volts, the circuit is open.

As we can see from the photograph, the backlight consists of 18 LEDs; during measurements, the voltage without load was 140 V, that is, each one accounted for 7.8 V. When we take into account the voltage drop on each strip and the total load, the conclusion will be as follows: this model uses 6V LEDs.

Finding a burnt-out LED is not easy: if there is no burnout at the mounting location, then you need to check each element separately.

Replacing LEDs

Replacing the Lg TV backlight can be a bit of a hassle. Let's say that the test results revealed several faulty LEDs. It is quite difficult to buy a replacement bar - these parts are not supplied to service centers, you can order them on the manufacturer's website, but this is time-consuming and very expensive. So there is only one way - replace separate diodes , although it will not be easy to find them on the radio market. Experts assure that you can buy already soldered ones, but in good working order; after a long search, these are exactly what we purchased.

Users should be aware that all planks are glued using double sided tape, so you need to warm them up with a special soldering hair dryer so that the adhesive tape comes off. To do this, the bar is fixed in the holder and heated from below with a hairdryer, the tin is melted, and the faulty part is removed. Soldering should be done using exactly the same method to avoid damaging the LED.

Important! All lenses are secured with a compound at the factory, so when removing them you must act very carefully, and each one must then be installed on old place, so as not to disturb the initial focus.

One more nuance: you may come across LEDs whose negative pad is slightly larger than the positive one, so you need to trim the contact point in order to solder the diode. This is what a soldered LED looks like:

The fact that the paint is a little damaged is not a problem. We solder the rest of the LEDs in the same way, and Glue the lenses with superglue. And this is a repaired view of the backlight panel assembled and ready for further use:

As we see in practice, in repair LED backlight LG TV matrix has many specific nuances, and without knowing them, it is impossible to achieve a positive result.

Final works

When the LG TV system has been completely repaired, before final assembly, we connect the voltage to the strips and check the glow of all LEDs. If everything is fine, then we assemble the TV, performing all operations sequentially and with caution, as during dismantling.

After finishing, it is better not to set the backlight brightness to maximum, but to limit it to 75% - in this mode, the LEDs operate at normal mode and, according to experts, they will last much longer.

We install the TV in its original place, turn it on and enjoy the quality: if there are no extraneous spots of light or dark color anywhere on the screen, it means that the repair was carried out correctly, in compliance with all recommendations. And you can get the most out of your TV by learning how to properly

The most reliable LG TVs of 2018

TV LG 22LH450V

TV LG 49UJ651V

TV LG OLED55C8

TV LG 55LJ622V

TV LG 55UK6100

Most homes have more than one TV. Maybe two, three or more. They are installed in different rooms - in the kitchen, in the living room, in the bedroom or in the nursery. Depending on the place of “registration”, the requirements and selection criteria change. So it turns out that choosing a TV is not so easy.

To choose a TV, you first need to decide at least on the technology by which it will be manufactured. They all have their pros and cons. But even the disadvantages can be used “for good.”

Plasma screens

The design of a plasma panel is fundamentally different from all other technologies. Between two glass plates there are cells filled with gas - xenon or neon. That’s why such TVs are sometimes called gas-discharge TVs. When current passes, the cells glow, the brightness of the glow depends on the magnitude of the current.

The main advantage of this technology: high quality of the “picture”, which is preserved even in very dynamic moments. Other advantages of this technology are no less impressive:

Very good indicators that contributed to the rapid growth of popularity. But there are also disadvantages:

If you want to choose a large screen TV, high-quality image and good color rendering, pay attention to plasma panels. This is exactly them. Only if you want, you will have to look for appropriate brackets and the wall must have good load-bearing capacity. Drywall or foam concrete will not hold such a mass.

Properties of LCD TVs (LCD)

LCD screens use digital way image transmission. They are so named because the cells are filled with liquid crystals, which in an electromagnetic field polarize the light passing through them, changing the degree of their own transparency. To obtain an image, a matrix with liquid crystals is illuminated from behind (cold cathode lamps), and color filters are used to convey shades.

Advantages LCD TVs the following:

Models recent years low power consumption.
Higher resolution (compared to plasma).
Possibility of playback in FullHD format.
Light weight.
There are screens different sizes- both small and large. The image on them has the same quality.
Good image geometry.
Low level electromagnetic radiation since they are powered by reduced voltage.
There is no screen burn-in or see-through.
The screen does not attract dust.

This set of qualities contributed rapid spread TVs with LCD screens. But they also have a number of disadvantages that are worth knowing about:

If you want to choose an LCD TV with good resolution, you will have to shell out a substantial amount. If the requirements for image quality are not so strict, it is quite possible to look at models from the mid-price range.

LED technology

The difference between LCD and LED TVs is in the various lamps used to backlight the matrix. LED TVs use LEDs. They are smaller in size, which allows for very thin screens. They are also more durable and consume less electricity. There are two types of LED screen backlighting:

Through the use of LEDs, LCD TVs receive additional advantages:

If you decide to choose a TV with high quality images, take a closer look at the LED models. They have, perhaps, only one drawback - the high price. Good quality led tv costs $600-1000. Compared to conventional LCDs, they cost 40-50% more. However, these are not the most expensive models today and many people opt for LED TVs.

OLED and QLED technology

This technology for making televisions appeared already in this century, and they have been mass-produced for only four years. The image is formed by organic light-emitting diodes, which emit light themselves and do not require backlighting. In English they are designated OLED, which gives the name to this type of TV.

Today there are two main technologies for producing OLED TVs:

The first technology turned out to be not the most successful. Due to the nature of production, it turned out to be difficult to find groups of LEDs with the same glow, which led to a large number marriage. For this reason, this technology is this moment recognized as unprofitable and all OLED TVs are made based on white LEDs. What is the difference between receivers of this type? Here are their advantages:

What are the disadvantages of this technology? First of all, it is the price. OLED TVs cost 4-5 times more than the cheapest LED ones. In addition, there are still very few videos released in 4K quality that will allow you to appreciate the benefits of such screens. Therefore, if you do not need to support the HDR-10 or Dolby Vision format, you do not need such a TV. At least for now. Still, there is nothing special to watch in the required quality. You can, of course, choose a TV in the long run - in 10 years this format will become familiar. But as technology develops, it becomes cheaper, so paying now a considerable amount for a new product, according to at least, irrational.

But OLED is not latest news. The latest technology is QLED, but it is even more expensive and therefore, for now, even more irrational.

How to choose TV screen size

You need to choose a TV according to the size of the room. Or rather, by the distance from the viewing location to the location of the screen. The larger the screen, the farther above it is located. Also, the distance to the TV depends on the screen resolution. The higher the resolution (more pixels per centimeter), the closer you can sit.

Experts believe that this is the only way to enjoy a realistic image and examine the smallest details. But not everyone is happy with this regime. It's too hard on the eyes. On average, it is believed that the distance to the screen should be at least three diagonals, but no more than 4-5.

Actually, based on this, you can choose the diagonal of the TV. You know at what distance you will sit, you can calculate what size screen will suit you. Just remember that the smallest plasma screens have a diagonal of 32″, and Full HD resolution is only available from 21″.

When choosing a placement location, also remember that for comfortable viewing, the middle of the screen should be at eye level.

What technical parameters should you use to choose a TV?

Although modern televisions created on the basis of different technologies, their selection criteria are the same. There are about 10 parameters that are worth paying attention to.

Perhaps these are all the characteristics that you should pay attention to if you want to choose a TV for your home. There is little point in going into even greater technical subtleties.

What else to pay attention to

There are a number of other features that are worth paying attention to, but which are not technical characteristics.

Availability of multimedia connectors

If the TV has connectors for connecting other devices, this greatly expands the possibilities of its use. There may be such connectors as HDMI, SCART, USB. Here's what they can provide:

To reduce costs, multimedia connectors are not installed, but their presence really wouldn’t hurt. And it is better to choose a TV in which the connectors are located in front (under a special cover), and not in the back. It will be much more convenient to use.

Supports 3D and SmartTV modes

The 3D mode allows you to see the image in three dimensions, “volumetric”. But you can only watch films/shows/programs recorded in this format in this mode. There are not many of them, and the effect will only be impressive on the big screen.

3D is not the best required function, although interesting

TVs that support the SmartTV function are practically a subtype of a computer or smartphone with the ability to connect to the Internet. In the most “standard” version, it is possible to access social networks and some voice and video messaging services. For more expensive models smart TVs It is possible to use Skype, surf the Internet using the built-in browser, watch video and audio recordings from the Internet (not necessarily only free content).

Picture in Picture

This feature allows you to watch two channels at the same time. How can you use this property? To watch programs without advertising. During the advertisement, you can turn on another program that interests you, and then switch to the “main” channel.

Frame within a frame - may be useful

Curved screens

TVs with large screens began to do not only with direct, but also with curved screen. Manufacturers claim that this improves perception. For those who sit exactly opposite, perhaps there are some positive changes. But if several people are sitting in front of the screen, then those sitting on the sides experience serious discomfort - the proportions are distorted due to the curvature of the screen.

Considering that a TV with a curved screen costs significantly more than a similar “straight” one, it becomes obvious that this is not the wisest use of money.

Ability to delete unnecessary channels

If you plan to use a satellite dish, this feature will be useful. Because without it you will have to manually rearrange the encrypted channels in the end of the list. This is a long and necessary procedure and it is better to avoid it.

Delete unnecessary channels — useful feature when connecting satellite dishes, so you need to choose a TV for satellite TV with this option