edge-lit lcd panel factory
Edge lit BLUs using light guide plates are mature technology and remain a cost effective back light for many types of displays. It creates uniform and bright light output in computer monitors, mobile devices, and commercial displays. LCDs driven by edge lit back light units are a mainstay in cost effective displays found in mobile phones, laptops, tablets, and automotive displays, to name a few. They are reliable and produce uniform light, but extracting the maximum light output can prove challenging. BrightView now offers Gain Enhancement films (GEFs) based on our micro lens array technology that provides a boost in brightness for edge lit displays. The GEF replaces the traditional down diffuser, resulting in a brighter, more efficient backlight.Up to 30% improvement in brightness compared to traditional down diffuser films
When comparing different models of televisions, you might see the term "edge-lit LED." All LED TVs are a type of LCD TV; the "LED" refers only to the kind of lighting source used to illuminate the LCD pixels in the television. There is more than one way to light the pixels. The two primary technologies are edge-lit and full-array.
In an edge-lit television, the LEDs that illuminate the LCD pixels are located only along the edges of the set. These LEDs face inward toward the screen to illuminate it.
In some poorer-quality edge-lit LEDs, uniform picture quality can be a problem. Because the LEDs are along the edges of the panel, quality declines as you approach the middle of the screen because a uniform amount of illumination is not reaching the pixels further from the edges. Again, this is more noticeable during scenes of darkness; the black along the sides of the screen is more gray than black (and corners can appear to have a flashlight-like quality of illumination emanating from the edges).
Full-array LED televisions use a full panel of LEDs to illuminate the pixels. Most of these sets also have local dimming, which means the LEDs can be dimmed in different regions of the panel while other areas are not. It helps improve black levels, which appear closer to black than dark gray.
In general, full-array LED is a superior technology when it comes to picture quality, but edge-lit sets have one significant advantage: depth. Edge-lit LED TVs can be much thinner than those lit with either a full LED panel or traditional fluorescent (non-LED) backlight. For that reason, most of the super-thin sets you see in stores will be edge-lit.
If you"re looking for the best possible picture quality, you are most likely to find it in a full-array LED display with local dimming. If you are primarily concerned about the appearance of the television and want an extremely thin screen, edge-lit is the style that will fit your needs.
LED-backlit LCD, which uses light-emitting diodes for backlighting is a common type of display on televisions and laptops. Unlike pure LED screens these LCDs are not self-illuminating and are reliant on the backlighting for illuminating the display. It is an advancement on the preceding cold cathode fluorescent technology and some manufacturers and retailers may advertise this type of screen as an LED TV.
Edge-lit is a type of screen backlighting that has LED lights lining either the top and bottom edges of the screen or the perimeter of the screen. This form of backlighting differs from others as the screen is not lit from behind, and often produces a more muted effect. An opaque piece of plastic called a diffuser light guide distributes the lighting across the rear of an LCD panel.
Edge-lit LEDs can be individually brightened or dimmed to provide the high degree of backlight control that screened content demands. Edge-lit screens can achieve this in one of two ways:
Direct-lit backlighting uses LED lighting across a television back panel. This form of backlighting initially used Cold Cathode Fluorescent Lamps (CCFLs) before transitioning to LED. The lighting is behind the LCD panel to provide consistent lighting across the entire screen.
Both types of backlighting provide the illumination LED screens required to produce a visible image. The main difference is that direct-lit backlights sit behind the LCD panel to provide the necessary lighting whereas edge-lit screens have LEDs sitting at the perimeter of the screen. Here are some other notable differences:
The first generation of LED backlighting was edge-lit. However, this early form of edge-lit technology caused the development of hotspots on the screen and the overall lighting was inadequate. As LED design became more efficient and effective, Samsung revisited this type of backlighting with a market-leading edge-lit LED television in 2009.
Direct-lit panels use a simple array of LEDs to provide uniform lighting across an entire LCD panel. The adoption of direct-lit screen technology in the 2000s was driven by the availability of white LEDs that could replace existing CCFL technology.
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What"s a backlight? Well, it"s the light source that is situated directly behind the LCD panel of the majority of TVs. It"s what makes the screen glow, what gives bright colors their vibrancy, and increasingly, what gives dark shadows their depth.
There"s a little more to the glowing panel of an LCD TV than you might expect. The LCD panel offers the shape and color components of an image, but it doesn"t actually produce any light of its own. And without light to produce the colors we see and project the image outward to the viewer, an LCD TV wouldn"t be worth much. Enter the humble backlight.
Behind the LCD panel is a backlight, and between the backlight and the LCD panel are usually a few layers of polarized filters, backlight diffusers, and other optical layers designed to turn this collection of tech components into a sharper viewable image.
You"ll have an LCD panel to provide much of the image content, and a backlight behind it to provide the light that makes that LCD panel visible and the colors vivid. But that backlight has undergone a lot of changes over time — several just within recent years. And a lot of the improvements we"ve seen in modern TVs can be traced to the humble backlight.
But with the advent of LCD-based flat screen TVs, the need arose for illumination, and originally that meant cold cathode fluorescent lamps (CCFL), a technology that"s similar to fluorescent and neon lighting. But because these lamps generate heat that can damage a display and aren"t terrible energy-efficient, they"ve pretty much disappeared from today"s TVs.
Instead, they were replaced by one of the biggest innovations in modern TV technology: LED backlighting. With this change, TV manufacturers started calling LCD TVs with LED backlight "LED TVs" to differentiate them from the older CCFL-lit models. But with the last CCFL TVs going off the market a decade ago, it"s just as likely that TV makers have kept the LED nomenclature around to blur the distinction between LCD TVs and OLED panels, which use a very different (and largely superior) display technology.
Edge-lit displays illuminate the LCD panel by setting a row of LEDs along the top and bottom edges of a screen, or ringing the perimeter of the TV frame with LED lights. This light is then distributed across the back of the LCD panel with a special diffuser light guide, a semi-transparent sheet of plastic that allows the light from the LED in the TV bezel to illuminate a larger portion of the display.
It"s a very cost effective way to light a TV, since it uses the least amount of LEDs. It also offers some level of dynamic backlight control for HDR support. On sets that are equipped to do so, portions of the edge lighting strips can be darkened or dimmed to provide deeper blacks, or brightened to accentuate brighter portions of the screen. However, since they don"t directly light the LCD panel from behind, the effect is considerably muted when compared to other backlight technologies.
Direct lit LED backlighting uses LED lighting across the back of the TV, directly behind the LCD panel, providing a fairly uniform amount of light across the screen. It also allows for a brighter picture, since it uses more LEDs, and is able to utilize more of the light coming from those LEDs.
However, an all-white back light alone has its limitations. Because the entire LCD panel is lit uniformly, there"s little to no dynamic range offered by the display.
Toshiba C350 Fire TV (2021 model)The Toshiba C350(opens in new tab) is one of the better Amazon Fire smart TVs we"ve reviewed, but the direct LED backlight is something of a double-edged sword. It"s better and brighter than a basic edge-lit LED backlight, and picture is better as a result, but the lack of local dimming means that – despite the TV"s support for Dolby Vision and HDR10 formats – HDR content just doesn"t look very good.
Local dimming has been further refined with the introduction of mini-LEDs. By shrinking the LED size down to about one-fifth the size – mini-LEDs measure 0.008-inch (200 microns) across – more LEDs can be packed into the backlight panel, and much smaller dimming zones to be used.
Samsung QN90A Neo QLED TVWhen it comes to the several TVs on the market that have mini-LED backlight, the Samsung Neo QLED takes the top spot, holding the top position among the best TVs we"ve reviewed. It"s a great TV for many reasons, but the impeccable backlight and HDR performance of the Samsung QN90A Neo QLED TV(opens in new tab) makes it one of the best LCD TVs we"ve ever seen.
OLED displays have individual pixels that light up without the need for a separate illumination source, creating a self-emissive display panel that doesn"t need any sort of backlight.
Most television companies, as well as sellers, misguide consumers by saying that this particular TV is not LCD but LED. So, first of all, we need to understand that all TVs are basically only
LCDs. What we refer to as LED is simply an update to the existing LCD panels. The panel technology is the same, however, the backlight is entirely different. Those LCDs that use LEDs as a light source are generally termed as LEDs. In short, a LED-backlight is a replacement for the uniform CCFL (Cold Cathode Fluorescent Light) backlight that previously gave LCD TVs its brightness.
Initially, there were only CCFL-backlit LCDs, but with advancement in technology, these CCFL were replaced by LEDs, as not only they dramatically reduced power consumption by over 40 percent compared to conventional CCFL-backlit LCDs, we got more control over the image quality by modulating these individual LEDs.
In the LED-backlit LCDs, LED lights can switch on and off individually, which allows the image to have greater contrast, bright whites and deep black in the same image. Thus, producing a superior picture when compared to CCFL-backlit LCDs. LCD TVs with LEDs also offer better response time in comparison to CCFL-backlit LCDs.
In the traditional LCDs, the CCFL lights were spread all across the surface behind the display screen, but there was no control over them. It means that when we switched on our TV, the entire surface behind the screen used to get illuminated by these CCFL lights that were always ON, and we were unable to control their dimming in specific areas of the screen.
Because of this, even the dark part of the picture used to be illuminated like the rest and we were unable to achieve images with convincing blacks, as light passed through the dark part of the picture and made it appear grey. In other words, the contrast of CCFL-backlit LCD panels isn’t very good. However, a plasma TV doesn’t have this problem as each pixel can light up or switch-off according to the demand of the picture.
Now coming to LCDs that use LEDs as the source of illumination, there are basically three types. One is Full-array backlighting, another is Edge-lit backlighting (ELED) and third is direct-lit LED backlights (DLED).
The term full-array is used where LEDs cover the entire back-side of the LCD panel. Full-array TVs are high-ends TVs that are heavier and often thicker, but they provide better picture quality as all parts of the screen are evenly backlit. They offer the most effective local dimming, as the LEDs are more in number and are spread over the entire back surface of the panel. The independent dimming of each LED in these TV sets helps in achieving perfect blacks. But, as they are costlier to manufacture, they are rare.
This technology allows the designing and manufacturing of exceptionally thin TV sets. Edge-lit sets also have a cost-benefit over direct, local dimming versions (DLED) as fewer LEDs are used in them. Because of which, they are power efficient too.
Direct-lit LED backlights are an offshoot of full-array backlighting, though they use significantly fewer LEDs across the back of the panel. In this technology, several rows of LEDs are placed behind the entire surface of the screen.
As the LEDs are behind the LCD panel in DLED TVs, dual modulation works far more efficiently and the TVs can have better overall brightness and contrast. Using a feature called local dimming, the LEDs are divided into a number of zones that can be individually controlled, so some portions of the backlight can be dimmed while other remain illuminated.
Though different brand TVs might be using the same DLED or ELED backlighting, their image quality might differ considerably depending on how many lights are used and how they are aligned. In some budget Edge-lit TVs, LEDs are aligned on only one side, either upper or lower edge of the TV panel, while others might have LEDs on both upper and lower edges of the panel. The high end TVs might even have a row of LEDs on all four edges of the panel. Some manufacturers use both Edge and Direct LED systems for LCD TVs. The best professional monitors use direct LEDs.
Though bigger brands like Sony, Samsung and LG also prefer EDGE-lit LED backlighting in their TVs, they complement it with some of their indigenously formulated technology to enhance the picture quality.
TV manufacturers lay more stress on producing TVs with ELED technology as it not only cut down upon their expenditure but allows them the liberty of producing ultra-slim TV sets that can appeal the masses with their aesthetically designed panels.
Modern LCD TVs rely on LED backlighting to produce the visuals you see on the screen. But their picture quality and price can differ based on their backlighting system. So, what are these backlighting systems, and how are they different?
LCD TVs can be grouped into three categories based on the type of LED backlighting system: Direct-lit, edge-lit, and full-array. As the name suggests, direct-lit TVs feature a panel of LEDs placed directly behind the display stack. Full-array TVs have a similar LED placement, but the number of LEDs is significantly more, and these LEDs are divided into different zones. But unlike both direct-lit and full-array TVs, edge-lit TVs have LEDs on the perimeter, and depending on the TV, these LEDs may or may not be grouped into multiple zones.
The LED backlight zones in full array and edge-lit TVs are significant as they enable the manufacturers to implement a feature called local dimming. It allows TVs to control the backlight on a scene-by-scene basis. So the TV can turn off LED backlighting in parts of the screen where it’s supposed to be darker while keeping other parts lit. As a result, LCD TVs with local dimming can produce deep, uniform blacks and have a better contrast ratio than the LCD TVs that don’t have this feature.
Direct lighting is the newest of the three types backlighting in LCD TVs. The first commercial direct-lit LCD TVs emerged around 2012 and are essentially an off-shoot of the full-array TVs.
But, the lower number of LEDs also means they have to be placed farther away from the screen to offer sufficient light coverage across the panel. As a result, direct-lit TVs are usually thicker than TVs with other backlighting systems.
Additionally, the lack of backlight control limits the contrast ratio of direct-lit LCD TVs to the native contrast ratio of the panel. So if a direct-lit TV uses a VA-type LCD panel, it will have a reasonable contrast ratio, but TVs with IPS-type panels have a poor contrast ratio.
Sony X85J is a direct-lit 4K LCD TV. It uses a VA-type panel and comes with features like HDMI 2.1 ports, VRR support, and Android TV operating system.
Edge LED backlighting first appeared in TVs in 2008, allowing for a thinner profile than LCD TVs with other backlighting solutions. But as the LEDs are placed on the rim of the screen, edge-lit TVs require a diffuser to light up the entire display adequately. This adds to their cost, making them slightly more expensive than direct-lit TVs. But given that backlighting is just one part of an LCD TV’s cost, you will find both cheap and costly edge-lit TVs on the market.
Some edge-lit TVs also come with local dimming support. But the number of backlight zones is typically far lower than in full-array TVs, and the individual LEDs are responsible for lighting up entire columns of the screen. So edge-lit local dimming is much less precise, and the benefit in terms of contrast ratio is minimal.
Full-array TVs have the best backlight implementation among LCD TVs. Not only do these TVs have a large number of LEDs, but the LEDs are also divided into multiple zones for dynamic backlight control. So, depending on the number of backlight zones and local dimming implementation, full-array TVs can have modest to excellent improvement over the native contrast ratio of the LCD panel.
Unfortunately, LCD TVs with full-array local dimming can also suffer from various screen artifacts, such as blooming and black crush, depending on the number of backlight zones and the overall local dimming implementation.
The Samsung QN90A is one of the best LCD TVs on the market and it uses full-array local dimming. The TV has 4K resolution, HDMI 2.1 port, and a 120Hz VA-type panel.
If you are shopping for a new TV and curious about its backlighting system, you can consult the TV’s specifications. Manufacturers generally mention whether an LCD TV is direct lit, edge lit, or full array. In the case of full-array TVs, the number of local dimming or backlight control zones is also listed in the TV’s specifications. This number is usually different for different sizes of a particular TV and can impact the amount of contrast ratio gain you can expect.
OLED TVs are self-emissive and don’t need a backlight, unlike LCD TVs. Instead, each pixel of an OLED panel can generate its own light and be switched off to display the perfect black color. So, OLED TVs essentially offer pixel-level local dimming. As a result, they have a near-infinite contrast ratio and are generally considered to have the best picture quality. But they are also typically more expensive than LCD TVs and can suffer from burn-in.
All-in-all, the backlight system of an LCD TV can impact its picture performance. And if you are shopping for a new TV, full-array TVs generally have the best picture quality. But if you are restricted by your budget, direct and edge-lit TVs can also deliver good visual performance. But make sure to read expert reviews to get a better idea about the overall quality of a particular television.
During the Consumer Electronics Show back in January, we noticed that some TV manufacturers were debuting LCD TVs with a new type of LED backlight, a direct-lit LED backlight.
At the time we didn"t know a lot about direct-lit LED backlights, but based on where these TVs were positioned in the manufacturer"s lineup—typically in or close to the entry-level series—it appeared that direct-lit LED backlight technology was able to bridge the price gap between lower-cost CCFL (fluorescent) backlights and the newer edge LED backlights that have become increasingly common in many LCD TVs. This year, for example, both Samsung (EH series) and LG (LS3400 series) are offering lower-priced LCD TVs with direct-lit LED backlights.
Most of the LCD TVs in our TV Ratings now come with edge LED backlights, where the LEDs are arrayed around the perimeter—typically the sides—of the TV. A waveguide (or lightguide, or diffuser) then spreads the light across the entire panel, hopefully in a uniform fashion.
The other type of LED-based backlighting we"ve seen—now less common—is a full-array LED backlight, where rows of LEDs are spread across the entire back panel of the TV. Using a feature called local dimming, the LEDs are divided into a number of zones that can be individually controlled, so some portions of the backlight can be dimmed while other remain illuminated. In some instances, we"ve seen this improve contrast and black levels. Some edge LEDs also have a form of local dimming, but this has had a negligible effect on contrast or black levels on most of the TVs we"ve tested.
Direct-lit LED backlights are an offshoot of full-array backlighting, in that they use LEDs spread across the entire back panel of the TV. (The TV"s spec page may just refer to these TVs as having a full-array backlight.) However, there are a few key differences compared to the more expensive full-array LED sets we"ve tested previously. One is that they use significantly fewer LEDs across the back of the panel. Another is that these sets lack the local dimming feature.
In addition, these TVs are much deeper than previous LED-backlit models, especially the ultra-thin edge LED sets. In fact, they more closely resemble LCD TVs with CCFL backlights. The reason: Because fewer LEDs are used, they have to be moved farther away from the screen to provide adequate light coverage across the panel, much the way the beam of a flashlight gets wider as you move it away from an object.
But the primary reason we"re seeing direct-lit LED backlights is price. Though they do cost a bit more than CCFL models, they"re less expensive than edge LED models, since they don"t require the lightguide plates. And in a tough economy, this lets manufacturers offer less-expensive models without having to forgo what has become perceived as a key LCD feature—an LED backlight. Although direct-lit LED backlights are no slimmer than CCFL-based LCD TVs, they do offer an advantage over models with fluorescent lights: better energy efficiency.
We"re currently testing a few Samsung models that use direct-lit LED backlights, so make sure to check out our TV Ratings in the next week or so to see how these sets fared. We"ll also be watching the market to see if more manufacturers embrace this type of backlight in their lower-priced LCD TV models.
Lightboxes can be built to your specifications regarding size, color temperature, and frame color. Single and double-sided [illuminated on the front and rear face] light panels are also available. Edge-lit panels are 8mm or about 1/3-inch thick a light panel including a flip-open frame [now called a lightbox] has a thickness of 0.625 to 1.50-inches. Illumination across the LED light panel from edge-to-edge is within 10% so a dark center is not a concern. Read more
Light panels have many uses in retail environments such as lighted shelves, signs or as a lightbox for photographic transparencies, stained glass and faux windows. For interior lighting applications, the panel performs well as a ceiling troffer, lighted wall, under cabinet light and under stone such as Onyx, quartzite or translucent man-made countertops. Read more
In signage, edge-lit panels can be a substitute for fluorescent tubes. Panels are thin, evenly illuminated and last for years without maintenance. Several color temperatures are available and RGB.
When displaying stained glass or some other translucent material in a window, you can use our clear edge-lit panel to let natural light through during the day and illuminate your art at night.
ST. PAUL, Minn.--(BUSINESS WIRE)--In an effort to meet LCD manufacturer design flexibility demands, the 3M Optical Systems Division today announced that it has developed a unique solution called Uniformity Tape that will allow LCD manufacturers to reduce the number of LEDs required for edge-lit LED LCD panels at a low cost, without sacrificing brightness or efficiency.
LEDs are becoming brighter and even more efficient-requiring fewer bulbs to achieve target brightness for a given display. Until now, there have been limitations as to how far LEDs can be spaced apart at the edge of an LCD panel because of dark areas that appear between LEDs when they are too far apart. This scenario is commonly referred to as "head-lighting" because it looks like the dark space on the road between the headlights of a car.
3M"s Uniformity Tape is a clear tape, which has adhesive on one side and a micro-replicated optical pattern on the other side. It is adhered to the edge of the light guide, which faces the LED light sources. The tape is designed to increase the spreading of light in the light guide from each LED, which greatly increases the allowable LED spacing. The optical pattern is spatially uniform, meaning that no positional registration of LEDs is required along its length. The Uniformity Tape keeps the edge of the display closest to the LEDs uniform in brightness when the spacing of light sources is increased. This allows panel manufacturers to save money by removing unnecessary LEDs. Uniformity Tape can also increase LED spacing by up to three times the current spacing, while maintaining edge uniformity for a given bezel size.
"As LED technology continues to improve and becomes even brighter, some backlight designs are currently using more LEDs than needed for a brightness specification in order to avoid head lighting or thick bezels. Uniformity constraints have also prevented manufacturers from removing LEDs to save on cost," noted Gilles Georges, 3M global marketing manager. "By spacing LEDs further apart for edge-lit LED LCD panels, 3M"s Uniformity Tape allows light to travel inside the light guide at wider angles-allowing manufacturers to design wider spacing between LEDs without any dark areas."
To help businesses transition from LCD to longer-lasting LED signage, Samsung has launched a trade-in program. Samsung will come on site to remove your existing display and provide a discount on a new LED bundle kit.
Traded-in LCD displays that are still operating will be refurbished and resold, and your business will receive a cash rebate. Nonworking displays will be recycled and their parts reused.