tft lcd vs wled brands
Confused about LED vs. LCD vs. TFT? Here"s everything you need to know. Creating or upgrading a device display or screen can involve a lot of different things, but it often comes down to one major question - what kind of display should you get?
So, there are 3 common displays LED, LCD and TFT available in the market. All terms refer to the flat-panel display, or screen, of a computer monitor or television set. In this article, we are going to differentiate between them. It will help you to choose a better one.
LCD stands for liquid crystal display. Works by adjusting the amount of light blocked. Usually has a backlight but might not (clocks, calculators, Nintendo Gameboy). The green-black ones can be very cheap and are a mature technology. Response time can be slow. An LCD display uses the light balancing qualities of crystals. Today LCDs are used in a great number of products and applications. Your TV, computer screen, calculator, cell phone and the dreaded alarm clock are all made of an LCD flat panel. Color LCDs produce the color based on two techniques: Passive matrix and active matrix. Passive matrix is the cheapest technology of the two. The other technology is called an active matrix or TFT. Active matrix displays produce really sharp and clear images.
This is a type of LCD with a thin film transistor attached to each pixel. All computer LCD screens are TFT since the early 2000s; older ones had slower response times and poorer color. Cost is now very good; power consumption is fairly good but dominated by the backlight. Has to be manufactured out of glass. The TFT layer is embedded in the screen itself, it reduces crosstalk between pixels. Crosstalk happens when a signal sends to a pixel also affects the pixel next to it. This makes the TFT technology the technology offering the best resolution and image quality. It also makes it a bit more expensive. Today TFTs have become the standard when producing LCD screens.
LED stands for a light emitting diode. As the name suggests, emits light rather than blocking it like LCD. Used for red/green/blue/white indicator lights everywhere. Some manufacturers advertise "LED" displays that are TFT screens with a white LED backlight, which is just confusing. Ones that are real LED screens are usually OLED.
An LCD panel is, in fact, 2 layers of glass with some volume of Liquid Crystal in between. These two form the panel itself. The 2 layers are usually called Color Filter Glass (above) and TFT glass (below).
LCDs can’t completely prevent light from passing through, though, even during dark scenes, so dimming the light source itself aids in creating deeper blacks and more impressive contrast in the picture.
A standard TFT has a whole "lamp" behind it, illuminating the whole screen all the time. This way, you cannot have a true black, as it is still illuminated and stay grayish.
TFTs are a type of active matrix display that controls individual pixel updates several times per second on the screen to update the image relative to the content source.
TFT displays use more electricity than regular LCD screens, so they not only cost more in the first place, but they are also more expensive to operate.
LCDs use fluorescent lights while LEDs use those light emitting diodes. The fluorescent lights in an LCD are always behind the screen. On an LED, the light emitting diodes can be placed either behind the screen or around its edges.
In market, LCD means passive matrix LCDs which increase TN (Twisted Nematic), STN (Super Twisted Nematic), or FSTN (Film Compensated STN) LCD Displays. It is a kind of earliest and lowest cost display technology.
LCD screens are still found in the market of low cost watches, calculators, clocks, utility meters etc. because of its advantages of low cost, fast response time (speed), wide temperature range, low power consumption, sunlight readable with transflective or reflective polarizers etc. Most of them are monochrome LCD display and belong to passive-matrix LCDs.
TFT LCDs have capacitors and transistors. These are the two elements that play a key part in ensuring that the TFT display monitor functions by using a very small amount of energy without running out of operation.
Normally, we say TFT LCD panels or TFT screens, we mean they are TN (Twisted Nematic) Type TFT displays or TN panels, or TN screen technology. TFT is active-matrix LCDs, it is a kind of LCD technologies.
TFT has wider viewing angles, better contrast ratio than TN displays. TFT display technologies have been widely used for computer monitors, laptops, medical monitors, industrial monitors, ATM, point of sales etc.
Actually, IPS technology is a kind of TFT display with thin film transistors for individual pixels. But IPS displays have superior high contrast, wide viewing angle, color reproduction, image quality etc. IPS screens have been found in high-end applications, like Apple iPhones, iPads, Samsung mobile phones, more expensive LCD monitors etc.
Both TFT LCD displays and IPS LCD displays are active matrix displays, neither of them can produce color, there is a layer of RGB (red, green, blue) color filter in each LCD pixels to make LCD showing colors. If you use a magnifier to see your monitor, you will see RGB color. With switch on/off and different level of brightness RGB, we can get many colors.
Neither of them can’t release color themselves, they have relied on extra light source in order to display. LED backlights are usually be together with them in the display modules as the light sources. Besides, both TFT screens and IPS screens are transmissive, it will need more power or more expensive than passive matrix LCD screens to be seen under sunlight. IPS screens transmittance is lower than TFT screens, more power is needed for IPS LCD display.
If you’re looking for a cheap LCD display, there are several options to choose from. Read on to learn about EL-WLED lcd displays and TN, DSM, and IPS lcds. These display types are a great option for any budget. Sharp Corporation is another great option. They have been producing high quality LCD displays for decades.
The EL-WLED tftmd089030 LCD display is an excellent choice for the 3D printer market. It features an 8.9-inch, 2560*1600 resolution IPS high-resolution LCD. This model does not include a touch panel, backlight driver or other accessories. Its measurement error is limited to 1-3 cm.
Among other benefits, it has a higher brightness level. Compared to CCFL backlighting systems, WLEDs are slightly more expensive. Some television manufacturers reserve WLED backlighting for high-end models while labeling all other sets as LCDs. Other uses of WLED backlighting include high-definition computer monitors, LCD displays, and various products. The price of WLED models differs from similar LCD models by several hundred dollars.
TN LCDs have a polarization effect because of the way light is polarized in a TN display. These displays use polarising filters, or parallel planes of glass with polarizing lines at right angles to each other. When light enters the display, an input filter polarizes it. As a result, it passes through the output filter, which matches the angle of rotation.
TN stands for twisted nematic and was the first LCD technology to hit the market. These panels have liquid crystals sandwiched between two polarizing filters. Electric current then twists these crystals, allowing light to pass through. TN panels are the most affordable and widely used in consumer electronics, but have poor color reproduction, viewing angles, and contrast ratios.
DSM LCDs are based on the Guest-Host interaction. While they were developed in the 1970s, few of these devices have been used in consumer products. Sharp Corporation, however, released calculators using their COS LCD technology in 1973. Sharp was also the first company to mass produce a TN LCD for a watch. In 1971, Seiko introduced a six-digit TN-LCD quartz wristwatch, while Casio introduced the Casiotron wristwatch.
These LCDs feature DSM technology, which provides excellent color quality, even under extreme conditions. The panel’s resolution is expressed in rows and columns. Each pixel has 3 sub-pixels. Traditionally, the performance of LCDs has been fairly consistent across designs, but some newer models share these sub-pixels with other pixels. Adding Quattron to these screens attempts to improve the perceived resolution, but the results are mixed.
IPS lcds are a type of liquid crystal display with positive dielectric anisotropy, which means they align with the long axis of the electrical field. A polarizer (P) on the backlight catches entering light, which is linearly polarized. A nematic LC layer rotates this polarization axis by 90 degrees, and then the electrical field (E) re-aligns them. This process is also known as a “IPS glow,” a bright yellow/white tinge seen on a display when viewing the display from a wide angle.
IPS monitors offer better color clarity and crystal Oriental arrangement than TFT monitors. IPS monitors also have a wider color gamut, and can be viewed from wide angles. The downside of IPS monitors is that they are more expensive than other LCD technologies. While IPS monitors offer better color gamut and more accurate reproduction, they do require more power.
Compared to EL-WLEDs, full-array WLEDs have a better contrast ratio, but they cost more. Some manufacturers reserve LED backlighting for their most expensive models and label the rest as LCDs. Some LCD backlighting systems also have a higher price tag, with WLED models typically costing several hundred dollars more than comparable LCDs.
There are numerous benefits to EL-WLED technology, which uses a backlight made of white LEDs. The light emitting diodes produce more light and last longer. In addition, LEDs can be easily recycled, unlike their CCFL counterparts. These monitors also have thin, low-power panels and easy disposal. The price tag on EL-WLED models is around $3,500, but this doesn’t mean that the display technology is better than other LCDs.
The most common form of monitor or TV on the market is LCD or Liquid Crystal Display. As the name suggests, LCDs use liquid crystals that alter the light to generate a specific colour. So some form of backlighting is necessary. Often, it’s LED lighting. But there are multiple forms of backlighting.
LCDs have utilized CCFLs or cold cathode fluorescent lamps. An LCD panel lit with CCFL backlighting benefits from extremely uniform illumination for a pretty even level of brightness across the entire screen. However, this comes at the expense of picture quality. Unlike an LED TV, cold cathode fluorescent lamp LCD monitors lack dimming capabilities. Since the brightness level is even throughout the entire array, a darker portion of scenes might look overly lit or washed out. While that might not be as obvious in a room filled with ambient light, under ideal movie-watching conditions, or in a dark room, it’s noticeable. LED TVs have mostly replaced CCFL.
An LCD panel is transmissive rather than emissive. Composition depends on the specific form of LCD being used, but generally, pixels are made up of subpixel layers that comprise the RGB (red-green-blue) colour spectrum and control the light that passes through. A backlight is needed, and it’s usually LED for modern monitors.
Please note that some of the mentioned types may be considered a sub-category of LCD TVs; therefore, some of the names may vary depending on the manufacturer and the market.
1)Film layer that polarizes light entering2)glass substrate that dictates the dark shapes when the LCD screen is on3)Liquid crystal layer4)glass substrate that lines up with the horizontal filter5)Horizontal film filter letting light through or blocking it6)Reflective surface transmitting an image to the viewer
While many newer TVs and monitors are marketed as LED TVs, it’s sort of the same as an LCD TV. Whereas LCD refers to a display type, LED points to the backlighting in liquid crystal display instead. As such, LED TV is a subset of LCD. Rather than CCFLs, LEDs are light-emitting diodes or semiconductor light sources which generate light when a current passes through.
LED TVs boast several different benefits. Physically, LED television tends to be slimmer than CCFL-based LCD panels, and viewing angles are generally better than on non-LED LCD monitors. So if you’re at an angle, the picture remains relatively clear nonetheless. LEDs are alsoextremely long-lasting as well as more energy-efficient. As such, you can expect a lengthy lifespan and low power draw. Chances are you’ll upgrade to a new telly, or an internal part will go out far before any LEDs cease functioning.
Ultimately, the choice between LED vs VA or any other display technology will depend on your specific needs and preferences, including things like size, resolution, brightness, and colour accuracy.
Please note that some of the mentioned types may be considered a sub-category of LED TVs; therefore, some of the names may vary depending on the manufacturer and the market.
Further segmenting LED TVs down, you"ll find TN panels. A TN or twisted nematic display is a type of LED TV that offers a low-cost solution with a low response time and low input lag.
Like TN, IPS or In-plane Switching displays are a subset of LED panels. IPS monitors tend to boast accurate colour reproduction and great viewing angles. Price is higher than on TN monitors, but in-plane switching TVs generally feature a better picture when compared with twisted nematic sets. Latency and response time can be higher on IPS monitors meaning not all are ideal for gaming.
QLED TV sets are thus able to achieve many more local dimming zones than other LED TVs. As opposed to uniform backlighting, local dimming zones can vary backlighting into zones for adjustable lighting to show accurate light and dark scenes. Quantum Dot displays maintain an excellent, bright image with precise colour reproduction.
Please note that some of the mentioned types may be considered a sub-category of Quantum Dot TVs; therefore, some of the names may vary depending on the manufacturer and the market. Also, it"s worth mentioning that not all brands use the same technology. Some are using QD films or QD-LEDs, others are using QD-OLEDs, and the list could go on.
An OLED or organic light-emitting diode display isn’t another variation of LED. OLEDs use negatively and positively charged ions for illuminating individual pixels. By contrast, LCD/LED TVs use a backlight that can make an unwanted glow. In OLED display, there are several layers, including a substrate, an anode, a hole injection layer, a hole transport layer, an emissive layer, a blocking layer, an electron transport layer, and a cathode. The emissive layer, comprised of an electroluminescent layer of film, is nestled between an electron-injecting cathode and an electron removal layer, the anode. OLEDs benefit from darker blacks and eschew any unwanted screen glow. Because OLED panels are made up of millions of individual subpixels, the pixels themselves emit light, and it’s, therefore, an emissive display as opposed to a transmissive technology like LCD/LED panels where a backlight is required behind the pixels themselves.
The image quality is top-notch. OLED TVs feature superb local dimming capabilities. The contrast ratio is unrivalled, even by the best of QLEDs, since pixels not used may be turned off. There’s no light bleed, black levels are incredible, excellent screen uniformity, and viewing angles don’t degrade the picture. Unfortunately, this comes at a cost. OLEDs are pricey, and the image isn’t as bright overall when compared to LED panels. For viewing in a darkened room, that’s fine, but ambient lighting isn’t ideal for OLED use.
As you can see, a wide variety of displays are available on the market today, each with their unique advantages and disadvantages. While many monitors and TVs are referred to by various names, such as LED, IPS, VA, TN, or QLED, many are variations of LCD panels. The specific technology used in a display, such as the colour of backlighting and the alignment of pixels, plays a major role in determining the overall picture quality.
LED-vs-LCD? Lately, choosing a TV has become like walking into a candy store. There are so many TV technology options to choose from, and each of them seems just as good.
Then there are the technical terms to deal with, such as LED TV, LCD TV, QLED TV, UHD TV, OLED TV, and more. You might feel like you need to be a tech pro just to watch your favourite TV show in the evening or enjoy a game with your friend.
Here at Dynamo LED, we offer both LED and LCD TVs, and we appreciate the benefits of both TVs. Be sure to check out our buying an LED Display guide for more info.
First, an important thing to understand is that the LED (Light Emitting Diode) monitor is an improvised version of the LCD (Liquid Crystal Display). This is why all LED monitor is LCD in nature, but not all LCDs are LED monitors.
LCD technology revolutionized monitors by using cold cathode fluorescent lamps for backlighting to create the picture displayed on the screen. A cold cathode fluorescent lamp (CCFL) is a tiny fluorescent bulb. In the context of this article, LCDs refer to this traditional type of CCFL LCD TVs.
Since LEDs replace fluorescent bulbs with light-emitting diodes, LED TVs are more energy-efficient than LCDs. A 32-inch LED TV screen consumes 10 watts less power than the same size LCD screen. The difference in power consumption increases as the size of the display increases.
Light-emitting diodes are considerably smaller than fluorescent lamps used in LCD monitors. Fluorescent lamps have a considerable thickness, but the thickness of diodes is next to none. Moreover, countless diodes are assembled in the same plane, so the thickness of the array isn’t increased no matter how many diodes are present.
Edge-lit LEDs have a slight drawback in viewing angle compared to LCDs, because of the position of the light source. However, direct-view LEDs offer a better angle for viewing than LCDs as the light source is evenly spread on the screen.
Since LED displays use full-array LED backlighting rather than one big backlight, LED TVs offer significantly better contrast than LCDs. LCD backlighting technology only shows white and black, but LED backlighting can emit the entire RGB spectrum, thereby providing a deeper RGB contrast.
If you wonder which display will last longer, this debate is also won by LED displays. LED televisions have a longer lifespan of 100,000 hours on average, compared to 50,000 hours provided by LCD televisions.
An LED display provides the option to dim the backlight, along with other eye comfort features. Not only that, it provides a wider viewing angle without harming image quality. Therefore, an LED display is far better for your eyes than an LCD.
In an LED display, a lot of smaller diodes are used and if a diode is damaged, it can be replaced. In an LCD, you will need to replace the entire bulb in case of damage. Therefore, an LED display is easier and cheaper to maintain than an LCD.
Since LEDs are a better and newer technology, the price of an LED display is higher than an LCD. However, this is only when we are considering the purchase cost.
The picture quality of an LED display is far better than an LCD. Due to modular light-emitting diodes, an LED screen produces better control over the contrast, rendering a clear picture. Also, LED provides RGB contrast, which can show truer blacks and truer whites.
Not to forget, they provide a shorter response time as well. Both of these factors result inLED displays having a better picture quality compared to LCD displays.
Since LED displays are considerably thinner than LCDs, they weigh considerably less. On average, an LED screen weighs about half of an LCD screen of the same size.
As you might have noticed by now, LED wins the battle with LCD without any doubt. This is because LED displays have an advantage in all the factors that matter when considering a purchase, except price.
LED screens are the first choice among the public today, across generations. All are opting to switch to LED from LCD to make their lives more enjoyable and better.
Many TVs use LCD (Liquid Crystal Display) panels that are lit by LED backlights. There are two popular types of LCD panels: In-Plane Switching (IPS) and Vertical Alignment (VA), and there are two main differences between each type. A VA panel usually has a high contrast ratio and narrow viewing angles. However, an IPS panel has low contrast and wide viewing angles. These are the main differences between each, and for the most part, panel type doesn"t affect other aspects of picture quality, like peak brightness, color gamut, or color accuracy.
For the purposes of this article, we"re going to compare two LED-backlit LCD TVs: the Sony X800H, which has an IPS panel, and the Hisense H9G, which has a VA panel. Due to their different panel types, there are three noticeable differences in picture quality: viewing angles, contrast, and black uniformity, so we"re going to look at each one.
Viewing angle refers to the angle at which you can watch the TV without seeing a noticeable drop in picture quality. IPS TVs are the clear winner here, as the image remains accurate when viewing from the side - you can see the differences in the videos above. This is their main advantage over VA panels. Most VA panel TVs have a noticeable loss in image accuracy when viewing from the side. The narrow viewing angle of VA-type TVs is also problematic when the TV is used as a PC monitor from up close since the edges of the display look washed out.
VA panels are far superior to IPS panels when it comes to this, so if you tend to watch movies in the dark, you likely want to get a TV with a VA panel. Most TVs use VA panels due to this main advantage, and high-end models may have a local dimming feature that further enhances black levels. On the other hand, IPS panels normally have low contrast, so blacks look closer to gray, but you may not notice the difference in contrast in bright environments.
LCDs function by having liquid crystals in little groups to form the pixels. These crystals react and change position when charged with electricity and, depending on their position, they allow a certain color of light to pass through.
TV manufacturers have come up with ways to improve LED TVs to increase picture quality. There are competing technologies, like OLED, which also present their own unique characteristics.
Unlike LED TVs, OLEDs don"t use a backlight and instead have self-emitting pixels. This allows the pixels to individually turn on and off, resulting in perfect blacks. This means that they also have perfect black uniformity as there"s no blooming around bright objects like on some LED TVs. They also have wide viewing angles, sometimes even wider than some IPS panels, so OLEDs are a good choice for wide seating arrangements.
However, the one major downside to OLEDs compared to LEDs is their risk of permanent burn-in. This could be problematic if you constantly watch content with static elements, like the news, or if you use it as a PC monitor. We don"t expect it to be an issue for people who watch varied content, but if you"re truly worried about it, LED TVs appear to be immune to burn-in.
Samsung released quantum dot TVs in 2015, which they later labeled as QLED in 2017. These TVs include a quantum dot layer between the LED backlights and the LCD panel to achieve a wider color gamut. Other companies like Vizio and TCL also use this quantum dot technology on their TVs. Adding this extra quantum dot layer doesn"t change the characteristics of the panel type; the VA panel on the TCL 6 Series/S635 2020 QLED still has a high contrast ratio and narrow viewing angles. Although most QLED TVs use VA panels, you can easily use an IPS panel as well.
Manufacturers have tried different techniques to improve the viewing angles on VA panels over the years, aiming to produce a perfect LCD panel with both wide viewing angles and high contrast. While they have yet to achieve that goal, a few TVs have hit the market that try to combine the best of both panel types. The first TVs with this viewing angle technology came out in 2018, and only a few high-end models like the Samsung Q90/Q90T QLED and the Sony X950H had this technology in 2020. These TVs are a bit unique, delivering noticeably better viewing angles than their pure VA counterparts, but still worse than true IPS panels. This comes at the expense of a lower contrast ratio, as these TVs have worse native contrast than most VA panels, but they"re still better than IPS panels. Combined with their local dimming features, they still produce deep blacks.
Between IPS and VA panels, neither technology is inherently superior to the other as they both serve different purposes. In general, IPS TVs have wide viewing angles suitable for when you want to watch the big game or your favorite show in a large seating arrangement. They"re also beneficial for use as a PC monitor since the edges remain accurate if you sit up close. However, VA panels are a better choice for watching content in dark rooms, as their improved contrast allows them to display deep blacks. Choosing between the two is a series of trade-offs and qualities, so choosing the best TV for your needs depends on your usage.
LED and QLED TVs are similar to each other as they each use LCD panels with LED backlights; the only difference is that QLED TVs use a quantum dot layer that allows them to produce a wider range of colors. OLED panels are completely different, as the pixels are self-lit and can turn themselves off when needed, allowing the TV to produce perfect blacks.
QLED is just a marketing term to signify that the TV uses a quantum dot layer. A few companies, like Samsung and TCL, officially label their TVs as QLED. Other manufacturers like Vizio and Hisense use quantum dot technology, but don"t use QLED in their marketing. To make things even more confusing, LG is releasing quantum dot TVs, marketed as QNED. Whatever these TVs are called, they all fall into the same quantum dot category. LED TVs use the same backlight as QLEDs, but they don"t have the quantum dot layer.
Picture quality between different OLED models doesn"t differ much, as they each offer similar picture quality. However, picture quality can change a lot between QLED and LED models, and there are even different types of LED-backlit LCD panels that have unique characteristics. You can read about the differences between VA and IPS panels here.
LED, which stands for light emitting diode, emerged in the TV market before QLEDs and OLEDs. They use LEDs to light up an LCD panel. Many LED TVs have a VA panel, which normally has a high contrast ratio and narrow viewing angles, and they can get very bright.
QLED TVs use traditional LCD panels lit by LEDs. Between the LCD layer and the backlight, a quantum dot layer filters the light to produce more pure and saturated colors. QLED is a marketing term used by a few companies, like Samsung and TCL, on their quantum dot TVs.
OLED TVs can adjust the luminosity of each pixel individually. This allows them to turn them completely off to show pure blacks. This gives them exceptional picture quality, and they have wide viewing angles.
In terms of contrast ratio and black uniformity, QLEDs and LEDs are very similar, since they use the same technology with a backlight. Most TVs use VA panels, which are generally known to have a high contrast ratio that produces deep blacks, and most high-end models have a local dimming feature that further deepens black level. However, some TVs have uniformity issues that cause blooming around bright objects, but this can vary between units. Local dimming can also help reduce any blooming.
There are also different types of LCD panels: IPS and VA. The large majority of LED and QLED TVs use VA panels, and IPS panels are usually found with LG models. VA-type panels have excellent contrast, while IPS panels have poor contrast, resulting in blacks that look gray. That"s why most TVs use VA panels, since having a higher contrast ratio improves the overall picture quality.
Our gray uniformity tests determine how well a TV displays a single color, and in this case, we test it using a gray image. There are no TVs with perfect uniformity; LED TVs, QLED TVs, and OLED TVs have different issues displaying entirely uniform colors. As shown in our pictures above, a gray image appears more uniform on most OLEDs. Both LED TVs show imperfections on the sides, as well as darker patches across the screen and in the corners. This is especially noticeable with the Samsung TV. OLEDs are generally better and more consistent with uniformity, because of how each pixel is independent of the others, while LED TVs rely on a backlight which, if damaged, can result in uniformity issues.
Below are pictures of 5% gray, which is near-dark, and both LEDs and OLEDs don"t have many issues displaying pure black images. Uniformity issues are most noticeable while watching sports or if you"re using the TV as a PC monitor, where there are large areas of solid colors. Hockey rinks, football fields, or even grassy hills have an unpleasant patchy or even dirty look on a TV with poor uniformity. This makes OLED TVs excellent for sports, but OLEDs still aren"t perfect, as there are tiny vertical and horizontal lines that you may notice in near-dark scenes.
The most obvious thing we can see is that LED/QLED TVs get significantly brighter than OLEDs. However, LED/QLED TVs can"t maintain the same peak brightness with different content, especially if the entire screen is lit up. This means that LED/QLED TVs can make small highlights in some scenes extremely bright, but if the entire scene is bright, the brightness decreases significantly. OLEDs also suffer from the same issue, especially with HDR content. They have an aggressive Automatic Brightness Limiter (ABL) that limits the brightness of the screen, so if you plan on watching a ton of HDR content, highlights don"t stand out as much as on QLED and LED TVs.
When QLEDs first became available, their main advantage against traditional LED TVs was their ability to display very wide color gamuts for HDR content. Although they still do, the competition has caught up and most high-end TVs can produce the wide color gamut needed for HDR. Even Samsung has been passed by other manufacturers in terms of color gamut; as you can see here, the LG actually displays a wider color gamut than the Samsung, and the Sony isn"t far behind. Vizio is known for their wide color gamuts with their quantum dot TVs, and the Vizio M7 Series Quantum 2020 actually has the widest color gamut we"ve tested, with perfect coverage of the DCI P3 color space used in most content.
A TV"s color gamut also has an effect on the color volume, which is what colors a TV can display at different luminance levels. A TV with good color volume can display bright and dark colors. This is where a QLED is superior to an LED or OLED; flagship QLEDs tend to get brighter and, combined with their wide color gamut, they display a good color volume. Some high-end LED TVs can also have a good color volume, but it won"t be as good as a QLED. Also, because OLEDs don"t get very bright, they have trouble displaying bright colors, but don"t have any problems with dark colors thanks to their near-infinite contrast ratio.
LED/QLED TVs with VA panels normally have narrow viewing angles, so you notice an inaccurate image the moment you start viewing off-center. However, IPS panel types have wide viewing angles, but not many manufacturers use this panel type because they also come with a low contrast ratio. Manufacturers have also started to implement new technologies with their VA-type panels to improve the viewing angles; as you can see above, the Samsung has wider viewing angles than the Sony thanks to Samsung"s "Ultra Viewing Angle" layer, even though they use the same panel type. In the end, neither QLED nor LED come close to matching the wide viewing angles on OLED TVs.
Image retention varies between units, even of the same model, so your results may vary. LED TVs aren"t immune to it, but most of them won"t show any, so if this important to you, it"s safer to pick an LED or QLED TV instead of an OLED.
Burn-in, unlike temporary image retention, is permanent. This is a common issue with OLEDs after constant exposure to static elements, like if you"re using it as a PC monitor or constantly watching the news. However, we don"t expect this to be an issue for most people who watch varied content, and companies have introduced settings to help reduce the risk, like "Pixel Shift" and "Screen Refresh" options. LED and QLED TVs appear to be immune to burn-in, so you can easily use them as PC monitors and not worry about damaging the panel.
When looking at different screens, you may notice that moving images react differently on every TV. The biggest reason for this is response time. LCD panels take time to switch from one color to another, and some are faster than others. The delay for a pixel to change state causes a trail to follow the moving object. Some TVs are worse than others, and when the response time is especially bad, an action scene can turn into a blurry mess.
Previously, OLED TVs were much more expensive to purchase than LED TVs. Over the course of the last few years, though, they greatly dropped in price and can currently be found for much more reasonable prices. However, you can find many great QLED TVs for cheaper, like the ones from budget companies like Hisense and TCL. Many high-end TVs use quantum dot layers, so only mid-range and entry-level models still have LED panels, and they can be found for cheap.
As for availability, only a handful of companies produce OLED TVs, with the majority coming from LG, and they"re usually only available in larger sizes. Their lineup is starting to include entry-level OLEDs, but since they offer mostly the same picture quality, the only differences between one model to the next is the features. Many of the big TV companies, with the exception of Sony, have produced quantum dot TVs, and LED models can be found from any manufacturer.
It may be interesting to see how long OLED TVs remain popular, considering their risk of permanent burn-in. They have undoubtedly the best picture quality compared to QLEDs and LEDs thanks to their near-infinite contrast ratio, but since they"re relatively new, we don"t know how long an OLED can last before you have to replace it.
There are two new technologies aimed at competing with OLEDs while improving picture quality and avoiding the burn-in risk. Mini LED was first introduced in 2019 with the TCL 8 Series 2019/Q825 QLED, and it seems like it"s becoming more popular in 2021. Samsung is expanding their QLED lineup to include Mini LED, aimed at combining the wide color gamut of quantum dot technology with the improved picture quality of Mini LED. Mini LED is similar to most modern LED TVs with an LCD panel, but the LED lights are smaller, allowing for better local dimming, contrast, and brightness.
There"s another, completely different technology called Micro LED. It doesn"t use an LCD panel and instead uses even smaller LED lights, and like OLEDs, they"re self-emissive, creating perfect blacks and without the risk of burn-in. However, it"s not available for consumer use just yet; Samsung has only announced a 99 and 110 inch model in 2021, which are designed for commercial use. Micro LED TVs are currently very expensive, but we might see them more widely available in the next few years.
TV technology has greatly improved to the point where there are competing panel types each with their own advantages and disadvantages. OLED TVs are different from QLED and LED TVs because they can individually turn on and off pixels, resulting in perfect blacks and wide viewing angles. However, LED and QLED TVs tend to get brighter, and the latter also displays a wider color gamut for HDR content. Lastly, OLED TVs can also suffer from permanent burn-in, which LED/QLEDs don"t, so if you normally watch a lot of content with static elements, it"s best to avoid OLED TVs.
The benefits of using LED TVs are minimal energy consumption, a long-lasting backlight with pictures being bright. IPS displays offer more image accuracy and have better color reproduction in small viewing angles. In short, when it comes to LED vs IPS, former are cheaper, though the advantage of an IPS screen is better picture quality. Having said that, Samsung"s Quantum Dot technology could boast of dramatically enhanced color compared to IPS panels.
Although LED panels are excellent in competitive gaming, IPS gaming monitors have various tricks, like better image colors than other technologies, including TN and VA panels (see VA panel vs IPS). If you want to play while getting the most accurate color depiction, choose IPS and make sure to go over our review of the best 32-inch gaming monitors, including this affordable Dell gaming monitor.
LED and IPS monitors (see also QLED) have excellent attributes with disadvantages as well. Before looking at the differences of screens featuring the two technologies, here is a look at the LCD (Liquid Crystal Display) technologies and also a LED vs LCD comparison.
LED (Light Emitting Diode) is a type of backlight technology in which the pixels light up. Many people confuse the difference between LED and LCD displays.
An LED monitor is a type of LCD monitor, and while both utilize liquid crystals for picture formation, the difference lies in LEDs featuring a backlight.
If you need LCD monitors with a quick response time, consider an LED display panel using either VA or TN technology. Such an LCD screen typically offers a 1ms response time. However, remember that these monitors tend to have smaller viewing angles and inferior image quality than an IPS monitor. Regardless, you can still get a considerably good performance when planning quick-action games provided you sit directly in front of the screen. In that case, vertical monitors may prove a viable option.
Below are some combinations of these two technologies:LCD monitors incorporating IPS panels and LED backlightLED-backlit with IPS panel or TN panel featuresIPS display featuring LCD or LED backlight technology
The cost of a monitor using IPS screen technology is approximately $100 or more, depending on whether the panel infuses other technologies like a TN panel or another type of LCD.
When picking a monitor, it is essential to get one that aligns with your application. If you want a monitor for creative visual applications, go for an IPS monitor. This LCD panel allows you to sit at more diverse angles, get elaborate graphics, and features color accuracy.
An LED monitor might be your go-to alternative if you want to spend less. Besides, you can pick from multiple options featuring LCD and TN panels to circumvent some shortcomings synonymous with LED displays. What"s more, their performance is more reliable.
Back in the day, there was only one display technology – the Cathode Ray Tube (CRT). CRT TVs are bulky and draw a lot of current. But the introduction of Liquid Crystal Display (LCD) TV sets changed all that. TVs became more compact and the impact on the electricity bill was less.
The viewer sees a picture when an LCD screen is backlit by Cold Cathode Fluorescent Lamps (CCFLs), which are placed on the edges or behind the LCD panel. CCFL-backlit TVs have now been replaced with LED-backlit TVs. The advantage with LED-backlit TVs is lower power consumption, longevity of the backlight and a generally brighter picture.
When LCD TVs began to gain popularity from about 2000 onwards, it had only one main competitor – the Plasma Display Panel (PDP). However, PDP TVs faded away as LCD TVs were much cheaper.
A Thin Film Transistor (TFT) display is a type of LCD but the former had better contrast. Apart from TV sets, TFT LCD screens are used in smartphones, handheld devices, calculators, car instrument displays among others.
In-Plane Switching (IPS) technology is another type of LCD TV technology. These panels are more accurate in their picture reproduction and show more accurate colour from narrow viewing angles. In simple terms, IPS was better than LCD.
TV sets with Organic Light Emitting Diode (OLED) displays are better than traditional LCD TVs that are backlit by CCFLs or LEDs. This is because OLED TVs do not need any backlighting. Therefore, these panels produce very deep blacks and this gives very good contrast. This, in turn, means better picture quality. This is good when it comes to future technologies like 4K picture resolution. They are power efficient too.
Quantum LED (QLED) is another technology that Samsung is pursuing actively. OLED TVs are known to be better in terms of sharpness and back levels than QLED TVs but the gap is narrowing.
Normal LED-backlit, OLED and IPS panel TVs are all generally safe bets. Getting too deep into these technologies before buying a TV will lead to confusion. Any company will obviously say that their product is the best with a lot of jargon thrown in.
An LED-backlit LCD is a liquid-crystal display that uses LEDs for backlighting instead of traditional cold cathode fluorescent (CCFL) backlighting.TFT LCD (thin-film-transistor liquid-crystal display) technologies as CCFL-backlit LCDs, but offer a variety of advantages over them.
While not an LED display, a television using such a combination of an LED backlight with an LCD panel is advertised as an LED TV by some manufacturers and suppliers.
A 2016 study by the University of California (Berkeley) suggests that the subjectively perceived visual enhancement with common contrast source material levels off at about 60 LCD local dimming zones.
LED-backlit LCDs are not self-illuminating (unlike pure-LED systems). There are several methods of backlighting an LCD panel using LEDs, including the use of either white or RGB (Red, Green, and Blue) LED arrays behind the panel and edge-LED lighting (which uses white LEDs around the inside frame of the TV and a light-diffusion panel to spread the light evenly behind the LCD panel). Variations in LED backlighting offer different benefits. The first commercial full-array LED-backlit LCD TV was the Sony Qualia 005 (introduced in 2004), which used RGB LED arrays to produce a color gamut about twice that of a conventional CCFL LCD television. This was possible because red, green and blue LEDs have sharp spectral peaks which (combined with the LCD panel filters) result in significantly less bleed-through to adjacent color channels. Unwanted bleed-through channels do not "whiten" the desired color as much, resulting in a larger gamut. RGB LED technology continues to be used on Sony BRAVIA LCD models. LED backlighting using white LEDs produces a broader spectrum source feeding the individual LCD panel filters (similar to CCFL sources), resulting in a more limited display gamut than RGB LEDs at lower cost.
A first dynamic "local dimming" LED backlight was public demonstrated by BrightSide Technologies in 2003,Sony in September 2008 on the 40-inch (1,000 mm) BRAVIA KLV-40ZX1M (known as the ZX1 in Europe). Edge-LED lighting for LCDs allows thinner housing; the Sony BRAVIA KLV-40ZX1M is 1 cm thick, and others are also extremely thin.
LED-backlit LCDs have longer life and better energy efficiency than plasma and CCFL LCD TVs.mercury, an environmental pollutant, in their manufacture. However, other elements (such as gallium and arsenic) are used in the manufacture of the LED emitters; there is debate over whether they are a better long-term solution to the problem of screen disposal.
Quantum dots are photoluminescent; they are useful in displays because they emit light in specific, narrow normal distributions of wavelengths. To generate white light best suited as an LCD backlight, parts of the light of a blue-emitting LED are transformed by quantum dots into small-bandwidth green and red light such that the combined white light allows a nearly ideal color gamut to be generated by the RGB color filters of the LCD panel. The quantum dors may be in a separate layer as a quantum dot enhacement film, or replace pigment-based green and red resists normally used in LCD color filters. In addition, efficiency is improved, as intermediate colors are no longer present and do not have to be filtered out by the color filters of the LCD screen. This can result in a display that more accurately renders colors in the visible spectrum. Companies developing quantum dot solutions for displays include Nanosys, 3M as a licensee of Nanosys, QD Vision of Lexington, Massachusetts, US and Avantama of Switzerland.Consumer Electronics Show 2015.quantum dot displays at CES 2017 and later formed the "QLED Alliance" with Hisense and TCL to market the technology.
Mini LED displays are LED-backlit LCDs with mini-LED–based backlighting supporting over a thousand full array local dimming (FALD) zones, providing deeper blacks and a higher contrast ratio.
Novitsky, Tom; Abbott, Bill (12 November 2007). "Driving LEDs versus CCFLs for LCD backlighting". EE Times. Archived from the original on 28 November 2010. Retrieved 21 November 2020.
LED TVs: 10 things you need to know; David Carnoy, David Katzmaier; CNET.com/news; 3 June 2010; https://www.cnet.com/news/led-tvs-10-things-you-need-to-know/
LCD Television Power Draw Trends from 2003 to 2015; B. Urban and K. Roth; Fraunhofer USA Center for Sustainable Energy Systems; Final Report to the Consumer Technology Association; May 2017; http://www.cta.tech/cta/media/policyImages/policyPDFs/Fraunhofer-LCD-TV-Power-Draw-Trends-FINAL.pdf Archived 1 August 2017 at the Wayback Machine
Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is switched ON. Vertical ridges etched on the surface are smooth.
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directlybacklight or reflector to produce images in color or monochrome.seven-segment displays, as in a digital clock, are all good examples of devices with these displays. They use the same basic technology, except that arbitrary images are made from a matrix of small pixels, while other displays have larger elements. LCDs can either be normally on (positive) or off (negative), depending on the polarizer arrangement. For example, a character positive LCD with a backlight will have black lettering on a background that is the color of the backlight, and a character negative LCD will have a black background with the letters being of the same color as the backlight. Optical filters are added to white on blue LCDs to give them their characteristic appearance.
LCDs are used in a wide range of applications, including LCD televisions, computer monitors, instrument panels, aircraft cockpit displays, and indoor and outdoor signage. Small LCD screens are common in LCD projectors and portable consumer devices such as digital cameras, watches, calculators, and mobile telephones, including smartphones. LCD screens have replaced heavy, bulky and less energy-efficient cathode-ray tube (CRT) displays in nearly all applications. The phosphors used in CRTs make them vulnerable to image burn-in when a static image is displayed on a screen for a long time, e.g., the table frame for an airline flight schedule on an indoor sign. LCDs do not have this weakness, but are still susceptible to image persistence.
Each pixel of an LCD typically consists of a layer of molecules aligned between two transparent electrodes, often made of Indium-Tin oxide (ITO) and two polarizing filters (parallel and perpendicular polarizers), the axes of transmission of which are (in most of the cases) perpendicular to each other. Without the liquid crystal between the polarizing filters, light passing through the first filter would be blocked by the second (crossed) polarizer. Before an electric field is applied, the orientation of the liquid-crystal molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic (TN) device, the surface alignment directions at the two electrodes are perpendicular to each other, and so the molecules arrange themselves in a helical structure, or twist. This induces the rotation of the polarization of the incident light, and the device appears gray. If the applied voltage is large enough, the liquid crystal molecules in the center of the layer are almost completely untwisted and the polarization of the incident light is not rotated as it passes through the liquid crystal layer. This light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts thus constituting different levels of gray.
The chemical formula of the liquid crystals used in LCDs may vary. Formulas may be patented.Sharp Corporation. The patent that covered that specific mixture expired.
Most color LCD systems use the same technique, with color filters used to generate red, green, and blue subpixels. The LCD color filters are made with a photolithography process on large glass sheets that are later glued with other glass sheets containing a TFT array, spacers and liquid crystal, creating several color LCDs that are then cut from one another and laminated with polarizer sheets. Red, green, blue and black photoresists (resists) are used. All resists contain a finely ground powdered pigment, with particles being just 40 nanometers across. The black resist is the first to be applied; this will create a black grid (known in the industry as a black matrix) that will separate red, green and blue subpixels from one another, increasing contrast ratios and preventing light from leaking from one subpixel onto other surrounding subpixels.Super-twisted nematic LCD, where the variable twist between tighter-spaced plates causes a varying double refraction birefringence, thus changing the hue.
LCD in a Texas Instruments calculator with top polarizer removed from device and placed on top, such that the top and bottom polarizers are perpendicular. As a result, the colors are inverted.
The optical effect of a TN device in the voltage-on state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, TN displays with low information content and no backlighting are usually operated between crossed polarizers such that they appear bright with no voltage (the eye is much more sensitive to variations in the dark state than the bright state). As most of 2010-era LCDs are used in television sets, monitors and smartphones, they have high-resolution matrix arrays of pixels to display arbitrary images using backlighting with a dark background. When no image is displayed, different arrangements are used. For this purpose, TN LCDs are operated between parallel polarizers, whereas IPS LCDs feature crossed polarizers. In many applications IPS LCDs have replaced TN LCDs, particularly in smartphones. Both the liquid crystal material and the alignment layer material contain ionic compounds. If an electric field of one particular polarity is applied for a long period of time, this ionic material is attracted to the surfaces and degrades the device performance. This is avoided either by applying an alternating current or by reversing the polarity of the electric field as the device is addressed (the response of the liquid crystal layer is identical, regardless of the polarity of the applied field).
Displays for a small number of individual digits or fixed symbols (as in digital watches and pocket calculators) can be implemented with independent electrodes for each segment.alphanumeric or variable graphics displays are usually implemented with pixels arranged as a matrix consisting of electrically connected rows on one side of the LC layer and columns on the other side, which makes it possible to address each pixel at the intersections. The general method of matrix addressing consists of sequentially addressing one side of the matrix, for example by selecting the rows one-by-one and applying the picture information on the other side at the columns row-by-row. For details on the various matrix addressing schemes see passive-matrix and active-matrix addressed LCDs.
LCDs are manufactured in cleanrooms borrowing techniques from semiconductor manufacturing and using large sheets of glass whose size has increased over time. Several displays are manufactured at the same time, and then cut from the sheet of glass, also known as the mother glass or LCD glass substrate. The increase in size allows more displays or larger displays to be made, just like with increasing wafer sizes in semiconductor manufacturing. The glass sizes are as follows:
Until Gen 8, manufacturers would not agree on a single mother glass size and as a result, different manufacturers would use slightly different glass sizes for the same generation. Some manufacturers have adopted Gen 8.6 mother glass sheets which are only slightly larger than Gen 8.5, allowing for more 50 and 58 inch LCDs to be made per mother glass, specially 58 inch LCDs, in which case 6 can be produced on a Gen 8.6 mother glass vs only 3 on a Gen 8.5 mother glass, significantly reducing waste.AGC Inc., Corning Inc., and Nippon Electric Glass.
In 1922, Georges Friedel described the structure and properties of liquid crystals and classified them in three types (nematics, smectics and cholesterics). In 1927, Vsevolod Frederiks devised the electrically switched light valve, called the Fréedericksz transition, the essential effect of all LCD technology. In 1936, the Marconi Wireless Telegraph company patented the first practical application of the technology, "The Liquid Crystal Light Valve". In 1962, the first major English language publication Molecular Structure and Properties of Liquid Crystals was published by Dr. George W. Gray.RCA found that liquid crystals had some interesting electro-optic characteristics and he realized an electro-optical effect by generating stripe-patterns in a thin layer of liquid crystal material by the application of a voltage. This effect is based on an electro-hydrodynamic instability forming what are now called "Williams domains" inside the liquid crystal.
In the late 1960s, pioneering work on liquid crystals was undertaken by the UK"s Royal Radar Establishment at Malvern, England. The team at RRE supported ongoing work by George William Gray and his team at the University of Hull who ultimately discovered the cyanobiphenyl liquid crystals, which had correct stability and temperature properties for application in LCDs.
The idea of a TFT-based liquid-crystal display (LCD) was conceived by Bernard Lechner of RCA Laboratories in 1968.dynamic scattering mode (DSM) LCD that used standard discrete MOSFETs.
On December 4, 1970, the twisted nematic field effect (TN) in liquid crystals was filed for patent by Hoffmann-LaRoche in Switzerland, (Swiss patent No. 532 261) with Wolfgang Helfrich and Martin Schadt (then working for the Central Research Laboratories) listed as inventors.Brown, Boveri & Cie, its joint venture partner at that time, which produced TN displays for wristwatches and other applications during the 1970s for the international markets including the Japanese electronics industry, which soon produced the first digital quartz wristwatches with TN-LCDs and numerous other products. James Fergason, while working with Sardari Arora and Alfred Saupe at Kent State University Liquid Crystal Institute, filed an identical patent in the United States on April 22, 1971.ILIXCO (now LXD Incorporated), produced LCDs based on the TN-effect, which soon superseded the poor-quality DSM types due to improvements of lower operating voltages and lower power consumption. Tetsuro Hama and Izuhiko Nishimura of Seiko received a US patent dated February 1971, for an electronic wristwatch incorporating a TN-LCD.
In 1972, the concept of the active-matrix thin-film transistor (TFT) liquid-crystal display panel was prototyped in the United States by T. Peter Brody"s team at Westinghouse, in Pittsburgh, Pennsylvania.Westinghouse Research Laboratories demonstrated the first thin-film-transistor liquid-crystal display (TFT LCD).high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays.active-matrix liquid-crystal display (AM LCD) in 1974, and then Brody coined the term "active matrix" in 1975.
In 1972 North American Rockwell Microelectronics Corp introduced the use of DSM LCDs for calculators for marketing by Lloyds Electronics Inc, though these required an internal light source for illumination.Sharp Corporation followed with DSM LCDs for pocket-sized calculators in 1973Seiko and its first 6-digit TN-LCD quartz wristwatch, and Casio"s "Casiotron". Color LCDs based on Guest-Host interaction were invented by a team at RCA in 1968.TFT LCDs similar to the prototypes developed by a Westinghouse team in 1972 were patented in 1976 by a team at Sharp consisting of Fumiaki Funada, Masataka Matsuura, and Tomio Wada,
In 1983, researchers at Brown, Boveri & Cie (BBC) Research Center, Switzerland, invented the passive matrix-addressed LCDs. H. Amstutz et al. were listed as inventors in the corresponding patent applications filed in Switzerland on July 7, 1983, and October 28, 1983. Patents were granted in Switzerland CH 665491, Europe EP 0131216,
The first color LCD televisions were developed as handheld televisions in Japan. In 1980, Hattori Seiko"s R&D group began development on color LCD pocket televisions.Seiko Epson released the first LCD television, the Epson TV Watch, a wristwatch equipped with a small active-matrix LCD television.dot matrix TN-LCD in 1983.Citizen Watch,TFT LCD.computer monitors and LCD televisions.3LCD projection technology in the 1980s, and licensed it for use in projectors in 1988.compact, full-color LCD projector.
In 1990, under different titles, inventors conceived electro optical effects as alternatives to twisted nematic field effect LCDs (TN- and STN- LCDs). One approach was to use interdigital electrodes on one glass substrate only to produce an electric field essentially parallel to the glass substrates.Germany by Guenter Baur et al. and patented in various countries.Hitachi work out various practical details of the IPS technology to interconnect the thin-film transistor array as a matrix and to avoid undesirable stray fields in between pixels.
Hitachi also improved the viewing angle dependence further by optimizing the shape of the electrodes (Super IPS). NEC and Hitachi become early manufacturers of active-matrix addressed LCDs based on the IPS technology. This is a milestone for implementing large-screen LCDs having acceptable visual performance for flat-panel computer monitors and television screens. In 1996, Samsung developed the optical patterning technique that enables multi-domain LCD. Multi-domain and In Plane Switching subsequently remain the dominant LCD designs through 2006.South Korea and Taiwan,
In 2007 the image quality of LCD televisions surpassed the image quality of cathode-ray-tube-based (CRT) TVs.LCD TVs were projected to account 50% of the 200 million TVs to be shipped globally in 2006, according to Displaybank.Toshiba announced 2560 × 1600 pixels on a 6.1-inch (155 mm) LCD panel, suitable for use in a tablet computer,
In 2016, Panasonic developed IPS LCDs with a contrast ratio of 1,000,000:1, rivaling OLEDs. This technology was later put into mass production as dual layer, dual panel or LMCL (Light Modulating Cell Layer) LCDs. The technology uses 2 liquid crystal layers instead of one, and may be used along with a mini-LED backlight and quantum dot sheets.
Since LCDs produce no light of their own, they require external light to produce a visible image.backlight. Active-matrix LCDs are almost always backlit.Transflective LCDs combine the features of a backlit transmissive display and a reflective display.
CCFL: The LCD panel is lit either by two cold cathode fluorescent lamps placed at opposite edges of the display or an array of parallel CCFLs behind larger displays. A diffuser (made of PMMA acrylic plastic, also known as a wave or light guide/guiding plateinverter to convert whatever DC voltage the device uses (usually 5 or 12 V) to ≈1000 V needed to light a CCFL.
EL-WLED: The LCD panel is lit by a row of white LEDs placed at one or more edges of the screen. A light diffuser (light guide plate, LGP) is then used to spread the light evenly across the whole display, similarly to edge-lit CCFL LCD backlights. The diffuser is made out of either PMMA plastic or special glass, PMMA is used in most cases because it is rugged, while special glass is used when the thickness of the LCD is of primary concern, because it doesn"t expand as much when heated or exposed to moisture, which allows LCDs to be just 5mm thick. Quantum dots may be placed on top of the diffuser as a quantum dot enhancement film (QDEF, in which case they need a layer to be protected from heat and humidity) or on the color filter of the LCD, replacing the resists that are normally used.
WLED array: The LCD panel is lit by a full array of white LEDs placed behind a diffuser behind the panel. LCDs that use this implementation will usually have the ability to dim or completely turn off the LEDs in the dark areas of the image being displayed, effectively increasing the contrast ratio of the display. The precision with which this can be done will depend on the number of dimming zones of the display. The more dimming zones, the more precise the dimming, with less obvious blooming artifacts which are visible as dark grey patches surrounded by the unlit areas of the LCD. As of 2012, this design gets most of its use from upscale, larger-screen LCD televisions.
RGB-LED array: Similar to the WLED array, except the panel is lit by a full array of RGB LEDs. While displays lit with white LEDs usually have a poorer color gamut than CCFL lit displays, panels lit with RGB LEDs have very wide color gamuts. This implementation is most popular on professional graphics editing LCDs. As of 2012, LCDs in this category usually cost more than $1000. As of 2016 the cost of this category has drastically reduced and such LCD televisions obtained same price levels as the former 28" (71 cm) CRT based categories.
Monochrome L