The main component of modern plasma panels is rightfully considered to be the matrix. They are presented in several varieties with their own parameters and characteristics. But their main function is the same - to ensure high quality of displayed images. This factor must be taken into account when choosing a TV or display, since each matrix is designed for specific operating conditions and works best in a specific environment. Next, let's look at which TVs have the best matrix.
What is a matrix
The general design of the matrix used in televisions is a system that includes narrow, colorless electrodes. They are placed parallel to each other in the same plane vertically or horizontally. If such a matrix is depicted as a diagram on paper, it will turn out to be a grid with square slots.
The entire set of electrodes is located inside plates made of film or glass. Electrodes located vertically do not touch each other. Thus, the matrix can be schematically represented as a sheet of paper with luminous dots printed on it. Lighting up in a certain sequence, they produce the desired image.
For the manufacture of matrices, special technologies are used that affect the quality of pictures broadcast from the screen. Conventionally, they can be divided into three main types:
- LCD. This technology is used in liquid crystal displays.
- LED. LED backlighting of LCD screens.
- Plasma. A special technology is used. An electric current is passed through the gas, under the influence of which light is emitted.
Currently, liquid crystal structures are considered the cheapest and most economical. In this regard, plasma products have practically already left the electronics market. At the same time, LCD matrices are available in several versions, with different properties and different prices. Despite the apparent commonality of the technology used, the image quality of each type differs significantly.
TVs. Part 1. Types of TVs, backlights and technologies, practical differences
Hello, dear habra community. I hope that this article can help people like me - those people who choose a TV, but do not have much knowledge of the subtle technical issues in this area. I would like to share with you my thoughts and practical conclusions about choosing a large and high-quality TV. For the last 3 years I have been watching 42″ LCD CCFL (this is when the image is formed by polarized light from fluorescent lamps passed through filters). In 2009, there was no 3D yet, and thin LED-backlit TVs were just appearing and cost a lot of money. It was purchased without much pain of choice for $1400. After a couple of years of contemplation, I realized that I was missing something in the image. What - I could not describe, since I did not have the necessary knowledge in this area. I knew for sure that I wanted a larger diagonal and deeper blacks.
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 screen of an LCD TV is obtained as a result of the passage of polarized light from a 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 LEDs are positioned with a certain periodicity (scattering and many other factors have their influence), in almost 100% of cases, LCD TVs with LED backlighting have uneven backlighting (clouding) - when areas that should remain black have a different gradation grey. The problem is partially solved by segmented LED backlighting.
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.
Disadvantages:
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 blacks (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:
Angles are larger than S-PVA (but smaller than IPS).
Deepest Black Level (0.02 - 0.06 nits) Cons:
Sharp doesn't produce enough of them. Installed in Philips 9-series TVs and top-end Sharp series.
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 at 42″. Plasma TVs do not have different types of 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.
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 (without 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 Disadvantages
— 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 image volume and depth - 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. — There is virtually no response time. — Free viewing angles Disadvantages
— Completely unsuitable for connecting to a computer due to the residual image — Photos show worse (since gradations are obtained using dithering) — High power consumption, not all models have high brightness. — High production costs, low margins—it’s 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.
- economical - wide viewing angles. Disadvantages:
- various degradation of pixels over time (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 - the brightness level that the TV shows when a signal of 255 is applied to it. These 2 characteristics 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 notice a deviation of DeltaE < 3, and zero indicates ideal color rendition. — 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.
Which matrix is better to choose for a TV?
With a wide variety of matrices, you should take advice from experts on choosing the most suitable option:
- In specific and inconvenient places, the viewing angle is of great importance. In this case, IPS is suitable.
- High and high-quality color rendering is provided by VA systems.
- For infrequent viewing, you can limit yourself to a budget option with a TN matrix.
- The best images are provided by OLED and QLED technologies. It is recommended to choose the first option without an additional white LED. The picture will be more contrasty with a wide viewing angle. However, the high price of these devices should be taken into account.
Summarizing
Now you know what the differences are between the screens built into different TVs. In short, the best technology is OLED - organic light-emitting diodes. In second place you can put QLED - quantum dots. Plasma panels would follow next if they were produced in our time. But with LED TVs everything is more complicated - they are divided into several subcategories that differ from each other.
What kind of TV is in your house? And are you thinking about buying an OLED model if you still haven’t got one? Share your thoughts in the comments.
Which matrix is better for a monitor?
Quite often, when buying a computer, the problem arises of what type of matrix to choose for the monitor. To do this, you need to compare several options and choose the most suitable one. The main parameters are:
- Viewing angle. In first place are the most expensive OLED and QLED. They are followed in descending order by IPS, VA and TN.
- Response time. OLED and TN have the best performance, despite the latter's low price. IPS and VA matrices are at an average level.
- Next, we select the color rendition. OLED and QLED are considered the most effective, followed by IPS and VA. In last place is TN.
- Contrast. For all matrices it is approximately at the same level as color rendition. The same applies to the cost of products.
The final choice is made individually, taking into account future operating conditions.
TN
These types of matrices are used in most relatively inexpensive TVs. The full name, translated into Russian, means “twisted crystal.” Thanks to the use of additional coating, which allows for wider viewing angles, there are models labeled TN+Film, positioning them as a means for watching movies with the whole family.
The matrix is structured and functions as follows:
- The pixel crystals are arranged in a spiral.
- When the transistor is turned off, no electric field is created and light penetrates through them naturally.
- Control electrodes are installed on each side of the substrate.
- The first filter, located before the pixel, has vertical polarization. The rear filter, located after the crystals, is built horizontally.
- Passing light through this field produces a bright point, which takes on a certain color thanks to the filter.
- When voltage is applied to the transistor, the crystals begin to rotate perpendicular to the plane of the screen. The degree of reversal depends on the height of the current. Thanks to this rotation, this structure allows less light to pass through, and it becomes possible to create a black dot. To do this, all cones of the crystals must “close”.
This type of matrix has occupied a budget niche in equipment for playing multimedia products. Thanks to this technology, you can get acceptable colors and enjoy watching your favorite shows and movies. The main advantage of this technology is financial accessibility. Another advantage is the speed of operation of the cells, which instantly transmits colors. Such models are also economical in terms of energy consumption.
But this type of matrix is not the best for a TV due to the difficulty of coordinating the simultaneous rotation of the cones of the crystals. The difference in the time result of this process leads to the fact that some pixel segments have already rotated completely, while others continue to partially transmit light. Flow dispersion produces a different color image depending on the angle of the viewer. As a result, if you look directly, you see a black car on the screen, and if the viewer watches from the side, then the same car appears gray to him.
Another disadvantage of TN technology is the inability to display the entire color palette contained in the material. For example, a film about underwater filming of a coral reef with its inhabitants will not look as colorful as on other models. To compensate for this, developers build a color replacement algorithm into the screen and alternately reproduce nearby shades.
Therefore, TN is suitable for viewing by a small circle of people looking at the screen at almost right angles. This way you can see the picture with the most natural colors possible. Other technologies have been developed for more demanding viewers.
Should you choose screen mirroring when buying a TV?
Simply put, screen mirroring means emulating exactly what's happening on your mobile device on your TV screen.
Screen mirroring requires the source device to be connected to a shared network to display the same content on the display screen, which in our case is the TV.
Screen mirroring technology has evolved significantly over the years, and the best method for screen mirroring varies due to various factors such as the age of the model and manufacturer of your smartphone, tablet, and TV.
Currently, there are two screen display options available to the masses, namely Chromecast and Miracast.
Chromecast
This is a simple dongle that must be plugged into the HDMI port of the receiver and must be connected to the Internet via a Wi-Fi network. Chromecast requires an application in order to be used.
Once chromecast is launched, the user can cast the content of their choice from the source device to the TV.
Brands that support chromecast on their smart TV are:
- Sony
- Toshiba
pros
- Works with most major mutli media applications
- High compatibility thanks to the use of the application
Minuses
- Cannot work offline, depends on internet
- Mirror screen may look spotty
Miracast
This is a dongle device that plays the contents of a portable device to another device and then to the TV. It installs a device to connect the device instead of connecting via the internet, making it independent of the internet connection.
Brands that support Miracast on their smart TV are:
- Sony
- LG
- Samsung
- Toshiba
- Panasonic
pros
- Content is duplicated from the source device without using an HDMI cable
- Internet independent
- Great for professional use
Minuses
- Doesn't work with Apple devices
IPS
These types of LCD matrices are developed by the famous Hitachi brand. Subsequently, companies such as Samsung and LG drew attention to IPS. The name itself is translated from English as switching in planes. The technology has a number of significant advantages compared to TN. It is often used in the manufacture of televisions. The advantages of this particular solution include a large viewing angle, higher quality color rendering (when compared with TN technology, where, as we remember, only 80% is transmitted).
However, this technology also has its certain disadvantages. These include lower response speed and the presence of pixelation in TVs with a small diagonal. The price of models with this technology is higher than that of TN TVs.
conclusions
Choosing a matrix is not a difficult task if you understand what kind of price-quality ratio you want to get in the end and if you are familiar with its characteristics. Before purchasing, be sure to find out what matrix is installed in the TV or monitor. If you are not completely sure, there are several ways to check and determine this. The market offers both cheaper options with lower quality and premium TV models using advanced technologies in the manufacture of matrices.
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Helpful tips on choosing the right screen types
Having understood the matrix models, you need to pay attention to the following parameters:
- Equipping with additional connectors (HDMI, USB) will expand the functionality of multimedia equipment
- The presence of the Smart TV function will allow you to turn your TV into a computer with Internet access
- The brand plays an equally important role when choosing a TV. It is better to give preference to reliable, proven brands rather than buy an analogue from a little-known company at a lower cost.
- The presence of HD and Full HD formats will have a positive effect on image quality
- Support for 3D format will allow you to watch movies in 3-dimensional projection
- You should pay attention to the response time of the matrix. The lower the number, the faster the picture will appear on the display. Moreover, this parameter is important when watching dynamic videos: blur is reduced to a minimum.
Each type of TV has its own pros and cons and different functionality. Therefore, when purchasing, it is important to proceed from your own budget and technical characteristics of the models.
TV
Plasma
The technology is based on the glow of a phosphor heated by ultraviolet rays. Each individual element is a light source. Moreover, it does not depend on other elements. Accordingly, there is no need for backlighting. The main manufacturers of TVs using this technology are companies such as LG, Panasonic and Samsung.
The advantages of plasma panels include high quality color rendering and depth, as well as the presence of a three-dimensional two-dimensional effect. In addition, plasmas have high-quality black color and excellent display of dynamic content. TVs with this technology have minimal response time and maximum viewing angles.
The disadvantages include the presence of a residual image (that is, the panel will not work normally with the computer), poor display of static backgrounds and high energy consumption.
