lcd screen burn in made in china

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Image burn-in, also referenced as screen burn-in or ghost image, is a permanent discoloration of sections on an electronic display caused by increasing, non-uniform use of the screen.

The term burn-in dates back to when old monitors using phosphor compounds that emit light to produce images lost their luminance due to severe usage in specific display areas.

Chances are you"ve encountered image burn-in and image retention before, but you didn"t know which one you were seeing. They both have the same visual effects, so it"s easy to mistake them for each other, but there"s one key difference:

Most of the time, these guides explain how image retention works and how you can speed up its recovery process. We want to clear up any confusion you might have about image burn-in and image retention on LCD and OLED displays.

Image retention, also known as ghosting or image persistence, is the temporary effect of images remaining visible on LCDs or OLEDs for a short period, usually a few seconds.

If the images fade away after a short time, you are dealing with temporary image retention. If the images stay permanently, you are dealing with image burn-in.

Image retention doesn"t require any intervention from the user to make it go away – it"ll do that by itself. Retention will often occur before burn-in does on newer display technology like our

using a screen saver, cycling various graphics on the screen to exercise the pixels, and powering off the display whenever possible will help clear the image retention on your display.

These are the same tricks you"ll see advertised as a "cure" for image burn-in, but don"t be fooled. There"s no fix for burn-in, only ways to prolong it from happening.

Before you assume your screen has burn-in damage, try these tips and wait to see if it"s just image retention. Image retention is a harmless and common occurrence on many screens.

Image burn-in is caused by screen pixels that stay activated in a static position for long periods of time.Think of a TV in a lobby or waiting area that"s always playing the same news channel. The news channel footer and logo get burned into the screen permanently, even when you change the channel.

When LCD or OLED pixels stay activated in a static position, they"ll eventually become "stuck" in that position. When this happens, you"ll notice a faded, stubborn image that persists on the screen.

After showing a static image for long periods of time, the crystals in a liquid crystal display become weaker to move, and have more difficulty turning from the fully "ON" position to the fully "OFF" position

When pixels fail to activate or deactivate entirely, it results in faded images that won"t clear from the screen. This is common in applications using character LCDs where the alphanumeric characters are updated less frequently.

OLEDs are unique because they don"t need a backlight to light up. Each pixel on the display is a self-illuminating LED, so they generate their own light. However, the pixels inevitably lose their brightness over time. The longer an OLED pixel is illuminated, the dimmer it will appear next to lesser-used pixels.

If a static image stays on an OLED display long enough, the pixels will leave a shadow behind the previous image, even when the display shows something completely different.

Remember: There"s no way to remove or reduce burn-in after it occurs. If a stubborn image persists for extended periods or after restarting your display, you"re likely dealing with image burn-in.

Even the most advanced displays will experience burn-in at some point, but there are some simple actions you can take to extend your screen"s lifespan before burn-in occurs. With the proper practices, you can get years of outstanding performance from your display without any burn-in effects.

If a power cycle isn"t an option, you can use the display ON/OFF command to turn off the display. Alternatively, you can put the display into sleep mode while retaining the display data in RAM.

A screensaver is a good alternative if you can"t turn your display off. For displays that don"t need to be ON at all times, it"s helpful to let the screen rest when not in use.

Get those pixels moving! The longer a pixel stays activated in a static position, the closer it gets to being burned in. You can exercise your screen"s pixels with scrolling text, moving images, or changing colors.

For an OLED display, decreasing the contrast will lower the brightness and reduce the rate of image burn. More illumination (brightness) requires more current, which reduces OLED pixel lifespans.

For a LCD display, lowering the contrast will put less stress on the liquid crystals and will help to reduce the rate of pixels becoming weak, or sticking.

Remember that image burn-in is not reversible and can not be fixed once it happens. Whether it is a scrolling effect, rotating pixels, using a screensaver, or turning off the screen when not in use, it"s essential to establish image burn-in preventive measures to help extend the lifespan of your display.

AMOLED burn-in on screens and displays is permanent. Fortunately, you can slow it down and reduce its visibility by using a few simple tricks, which can also increase battery life.

Each pixel within an Active Matrix Organic Light-Emitting Diode (AMOLED) comprises red, green, and blue (and sometimes white) sub-pixels. When they emit light, they decay. Burn-in appears because individual sub-pixels lose brightness at different rates, depending on its color. The most-used light-emitting sub-pixels, such as for navigation and status icons, wear out first, leading to uneven light production.

So the more you use the device, the more visible its burn-in. And the longer you display the same image, the more that image"s outline will persist on the display.

It doesn"t help that many user-interface buttons are white. For an AMOLED panel to produce white light, the display switches on three different sub-pixels in proximity to one another. Each sub-pixel produces a different color: red, blue, and green. Together they appear white to the human eye. However, each of the three colors wears out at different rates, depending on the manufacturer.

For the AMOLED on most smartphones, red sub-pixels are the most durable, followed by green. Blue decays the fastest. When you see burn-in, it"s often caused by a weakening blue sub-pixel. All "fixes" aim at addressing the failing blue sub-pixel. Remember, there are also tools available to fix dead pixels.

Everyone with an OLED display has some burn-in. But often, it"s not fully visible unless you display a solid color at maximum brightness. The Android operating system has access to many apps that detect burn-in damage. The best of these is Screen Test.

Screen Test is ultra-simple: install and run the app. Touching the screen shifts between colors and patterns. If you see a persistent image impression or blotchy coloration, you have burn-in.

For my AMOLED phone, I"ve taken every precaution against screen burn-in. Even so, the display is still a little blotchy after over a year of use. Fortunately, there are no indications of burn-in where the navigation buttons are.

Android 10"s dark mode finally allows for Android system menus and apps to appear dark in color. It will turn Chrome"s user interface black, as well as the Settings menu, navigation bar, and notifications shade.

Android made it possible to get rid of the navigation bar in Android 10. Once enabled, gestures allow navigation by swiping your finger on the screen. You can enable Gesture mode by doing the following:

Some might notice that the stock wallpapers in Android aren"t usually suited for OLED screens. OLED screens consume very little energy when displaying the color black, and they do not burn-in when displaying black. Unfortunately, older Android versions don"t include a solid black wallpaper option.

Fortunately, the free app Colors, from developer Tim Clark, allows users to change their wallpaper to a solid color. Just install and run the app, then choose a solid black background as the new wallpaper.

Using black wallpaper will improve the battery performance of your device, so this one is a win-win. However, if you have Android 8.0 or newer, you might already have solid colors available as a wallpaper.

If you don"t have Android 10 or newer, the default Android Launcher isn"t OLED friendly. In Android 5.0, it forces the App Drawer wallpaper to white (the worst color for OLED screens). One of the best launchers for darker colors is Nova Launcher. Not only is it more responsive, it offers better customization options.

Minma Icon Pack changes your bright, screen-damaging icons into a darker, OLED-friendly palette. Over 300 icons are available, which cover the default icons as well as many others.

Firefox Mobile is infinitely customizable. While they, unfortunately, removed many of their browser"s mobile add-ons, you can still turn entire webpages black. And, on top of that, Firefox includes a dark theme.

I recommend installing an add-on. The easiest-to-use add-on is Dark Reader. Dark Reader does more than just change the color of Firefox"s user interface; Dark Reader can change webpages" to black backgrounds with red text, reducing eye strain and burn-in while also improving battery life.

Android"s dark-themed virtual keyboard options can reduce burn-in (and improve battery life). The best of these is SwiftKey, which allows users to change the color of their keyboards. The best SwiftKey theme I"ve seen so far is the Pumpkin theme. If you turn on Android"s dark theme, it automatically turns the keyboard black. In this case, you can simply use the default keyboard.

There are a few other burn-in repair tools, but I don"t recommend them since they either require root access and/or can increase screen damage. However, for reference, you can read about them below and why using them is a bad idea. They fall into two categories:

I do not recommend using this option unless your screen is already trashed. It will cause additional damage but may reduce the appearance of already existing on-screen burn. Inverting colors simply reverses the colors displayed on your screen. Whites become blacks and vice-versa.

If you use the phone with the colors inverted for extended periods of time, it will burn-in the areas surrounding the burned-in navigation bar, reducing its visibility.

Android 4.0 (Ice Cream Sandwich) introduced the Invert colors option to help the visually impaired. It"s not at all designed to combat burn-in and remains experimental. To invert colors, take the following steps:

Several tools claim to reduce the appearance of burn-in by attempting to age the entirety of your OLED panel. These screen burn-in tools flash red, green, and blue (or other) colors on your screen.

The reason is pretty simple: AMOLED burn-in occurs as a natural part of an organic LED"s life cycle. Therefore, tools that claim to fix AMOLED burn-in will cause uniform damage across all AMOLED pixels thus potentially worsening its image quality.

None of these methods will stop the inevitable and slow destruction of your device"s screen. However, using all the recommended options in this article will dramatically decrease the rate at which it decays. That said, some of the oldest AMOLED phones have very little burn-in. The decay of organic LEDs is almost entirely aesthetic, particularly on newer phones.

BOE, a leading Chinese display manufacturer and the company responsible for the spectacular LED stand at the recent Winter Olympics opening ceremony, has reportedly developed a new technology that it believes could solve the burn-in problem in OLED (Organic Light-Emitting Diode) screens that leaves visible, long-lasting marks. According to Android Authority, OLED screens are made of self-luminous organic materials which inevitably age, with uneven aging leading to burn-in problems on the screens. A patent filing originally made in 2018 but which has only just come to light, suggests that BOE has developed a method that makes the aging process more consistent across the screen by auto-detecting static pixels and adjusting the display position of the next frame to even out the effects of the stationary pixels. The micro movements are small enough that they cannot be detected by the human eye, but could have a major impact on the screen’s lifecycle. [ijiwei, in Chinese]

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That said I would describe the risk as possible but low. Being an LCD, as opposed to Plasma, and an OEM from Samsung (iirc) of the professional display line, these are pretty hardy units. The risk is there but if your content changes fairly frequently it should only be a problem over the longest of time scales. In other words you"ll likely replace the product under normal depreciation/life cycle first.

I recently noticed a small burn-in on my phone which definitely wasn"t there before. It"s a thin, slightly rounded dark line which looks blurry (definitely not dead pixels, I know what that looks like). This looks more like a small stain like when I touch the screen (especially swipe) right after washing my hands while they"re still wet, but no, it"s not that.

My previous phone (Samsung Galaxy S7, OLED) was full of burn-ins which were very visible, even though I took care of it as much as I could. What I love the most about LCD is that there"s no burn-in risk. Well, sure, it can happen on every type of display, but very unlikely on LCD, and even if it does happen, it"s temporary and it"s called image retention, not burn-in.

If it"s temporary, how can I get rid of it? Powering off the phone and leaving it like that all night or playing those videos that quickly switch between red, green and blue pixels?

Screen burn-in, image burn-in, or ghost image, is a permanent discoloration of areas on an electronic display such as a cathode ray tube (CRT) in an old computer monitor or television set. It is caused by cumulative non-uniform use of the screen.

One way to combat screen burn-in was the use of screensavers, which would move an image around to ensure that no one area of the screen remained illuminated for too long.

With phosphor-based electronic displays (for example CRT-type computer monitors, oscilloscope screens or plasma displays), non-uniform use of specific areas, such as prolonged display of non-moving images (text or graphics), repetitive contents in gaming graphics, or certain broadcasts with tickers and flags, can create a permanent ghost-like image of these objects or otherwise degrade image quality. This is because the phosphor compounds which emit light to produce images lose their luminance with use. This wear results in uneven light output over time, and in severe cases can create a ghost image of previous content. Even if ghost images are not recognizable, the effects of screen burn are an immediate and continual degradation of image quality.

The length of time required for noticeable screen burn to develop varies due to many factors, ranging from the quality of the phosphors employed, to the degree of non-uniformity of sub-pixel use. It can take as little as a few weeks for noticeable ghosting to set in, especially if the screen displays a certain image (example: a menu bar at the top or bottom of the screen) constantly and displays it continually over time. In the rare case when horizontal or vertical deflection circuits fail, all output energy is concentrated to a vertical or horizontal line on the display which causes almost instant screen burn.

Screen burn on an amber CRT computer monitor. Note that there are two separate burned-in images: one of a spreadsheet program, and another of an ASCII-art welcome screen.

Phosphor burn-in is particularly prevalent with monochromatic CRT screens, such as the amber or green monochrome monitors common on older computer systems and dumb terminal stations. This is partly because those screens displayed mostly non-moving images, and at one intensity: fully on. Yellow screens are more susceptible than either green or white screens because the yellow phosphor is less efficient and thus requires a higher beam current. Color screens, by contrast, use three separate phosphors (red, green, and blue), mixed in varying intensities to achieve specific colors, and in typical usage patterns such as "traditional" TV viewing (non-gaming, non-converged TV usage, non-Internet browsing, broadcasts without tickers or flags, no prolonged or permanent letterboxing) are used for operations where colors and on-screen object placement approach uniformity.

Modern CRT displays are less susceptible than older CRTs prior to the 1960s because they have a layer of aluminum behind the phosphor which offers some protection. The aluminum layer was provided to reflect more light from the phosphor towards the viewer. As a bonus, the aluminum layer also prevented ion burn of the phosphor and the ion trap, common to older monochrome televisions, was no longer required.

A nearly two-year-old LCD television showing extreme burn-in of CNN"s circa 2008 digital on-screen graphic; this television is in a McDonald"s restaurant where CNN is permanently turned on and displayed throughout the business day.

In the case of LCDs, the physics of burn-in are different than plasma and OLED, which develop burn-in from luminance degradation of the light-emitting pixels. For LCDs, burn-in develops in some cases because pixels permanently lose their ability to return to their relaxed state after a continued static use profile. In most typical usage profiles, this image persistence in LCD is only transient.

Both plasma-type and LCD-type displays exhibit a similar phenomenon called transient image persistence, which is similar to screen burn but is not permanent. In the case of plasma-type displays, transient image persistence is caused by charge build-up in the pixel cells (not cumulative luminance degradation as with burn-in), which can be seen sometimes when a bright image that was set against a dark background is replaced by a dark background only; this image retention is usually released once a typical-brightness image is displayed and does not inhibit the display"s typical viewing image quality.

Screensavers derive their name from their original purpose, which was an active method of attempting to stave off screen burn. By ensuring that no pixel or group of pixels was left displaying a static image for extended periods of time, phosphor luminosity was preserved. Modern screensavers can turn off the screen when not in use.

In many cases, the use of a screensaver is impractical. Most plasma-type display manufacturers include methods for reducing the rate of burn-in by moving the image slightly,Android Wear watches with OLED displays can request that Android Wear enable "burn protection techniques" that periodically shift the contents of the screen by a few pixels.

Other examples: Apple"s iPhone X and Samsung"s Galaxy series both mitigate or delay the onset of burn-in by shifting the pixels every minute or so for the battery, Wi-Fi, location, and service bars. Also, parallax scrolling may be enabled for the home screen to give icons a 3D-like effect, a setting Apple refers to as "perspective zoom". AG Neovo patented Anti-burn-in technology is also using pixel shifting to activate the pixels to move by the designed time interval to prevent burn in effect on LCD monitors.

Google requests that when these techniques are enabled, watch face developers do not use large blocks of pixels so that different pixels are burned in with each shift, reducing the overall wear of the pixels.

Some screensavers move around, such as those on DVD players or those on some television sets that move around paused video after a long period of inactivity.

Depending on the type of screen, it is sometimes possible to remedy screen burn-in through the use of remedial software and remedial devices. In the case of OLED screens on Android phones, burn-in reduction apps can display an inverted image of the navigation and status bars (which are constantly displayed and therefore the most likely elements to be burned in) to burn in opposite pattern, resulting in a screen whose sub-pixels have more even luminosity and therefore less visible burn-in artifacts.

The most prevalent burn-in image on early televisions was said to be that of the RCA Indian-head test pattern, which would often follow the formal television station sign-off. This was due to the viewer leaving the television set on at the end of the day, which was not recommended by the television manufacturers.

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.

The origins and the complex history of liquid-crystal displays from the perspective of an insider during the early days were described by Joseph A. Castellano in Liquid Gold: The Story of Liquid Crystal Displays and the Creation of an Industry.IEEE History Center.Peter J. Wild, can be found at the Engineering and Technology History Wiki.

In 1888,Friedrich Reinitzer (1858–1927) discovered the liquid crystalline nature of cholesterol extracted from carrots (that is, two melting points and generation of colors) and published his findings at a meeting of the Vienna Chemical Society on May 3, 1888 (F. Reinitzer: Beiträge zur Kenntniss des Cholesterins, Monatshefte für Chemie (Wien) 9, 421–441 (1888)).Otto Lehmann published his work "Flüssige Kristalle" (Liquid Crystals). In 1911, Charles Mauguin first experimented with liquid crystals confined between plates in thin layers.

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 1964, George H. Heilmeier, then working at the RCA laboratories on the effect discovered by Williams achieved the switching of colors by field-induced realignment of dichroic dyes in a homeotropically oriented liquid crystal. Practical problems with this new electro-optical effect made Heilmeier continue to work on scattering effects in liquid crystals and finally the achievement of the first operational liquid-crystal display based on what he called the George H. Heilmeier was inducted in the National Inventors Hall of FameIEEE Milestone.

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 LEDs: such as red, green, yellow or blue LEDs are used in the small passive monochrome LCDs typically used in clocks, watches and small appliances.

Mini-LED: Backlighting with Mini-LEDs can support over a thousand of Full-area Local Area Dimming (FLAD) zones. This allows deeper blacks and higher contrast ratio.

Today, most LCD screens are being designed with an LED backlight instead of the traditional CCFL backlight, while that backlight is dynamically controlled with the video information (dynamic backlight control). The combination with the dynamic backlight control, invented by Philips researchers Douglas Stanton, Martinus Stroomer and Adrianus de Vaan, simultaneously increases the dynamic range of the display system (also marketed as HDR, high dynamic range television or FLAD, full-area local area dimming).

The LCD backlight systems are made highly efficient by applying optical films such as prismatic structure (prism sheet) to gain the light into the desired viewer directions and reflective polarizing films that recycle the polarized light that was formerly absorbed by the first polarizer of the LCD (invented by Philips researchers Adrianus de Vaan and Paulus Schaareman),

A pink elastomeric connector mating an LCD panel to circuit board traces, shown next to a centimeter-scale ruler. The conductive and insulating layers in the black stripe are very small.

A standard television receiver screen, a modern LCD panel, has over six million pixels, and they are all individually powered by a wire network embedded in the screen. The fine wires, or pathways, form a grid with vertical wires across the whole screen on one side of the screen and horizontal wires across the whole screen on the other side of the screen. To this grid each pixel has a positive connection on one side and a negative connection on the other side. So the total amount of wires needed for a 1080p display is 3 x 1920 going vertically and 1080 going horizontally for a total of 6840 wires horizontally and vertically. That"s three for red, green and blue and 1920 columns of pixels for each color for a total of 5760 wires going vertically and 1080 rows of wires going horizontally. For a panel that is 28.8 inches (73 centimeters) wide, that means a wire density of 200 wires per inch along the horizontal edge.

The LCD panel is powered by LCD drivers that are carefully matched up with the edge of the LCD panel at the factory level. The drivers may be installed using several methods, the most common of which are COG (Chip-On-Glass) and TAB (Tape-automated bonding) These same principles apply also for smartphone screens that are much smaller than TV screens.anisotropic conductive film or, for lower densities, elastomeric connectors.

Monochrome and later color passive-matrix LCDs were standard in most early laptops (although a few used plasma displaysGame Boyactive-matrix became standard on all laptops. The commercially unsuccessful Macintosh Portable (released in 1989) was one of the first to use an active-matrix display (though still monochrome). Passive-matrix LCDs are still used in the 2010s for applications less demanding than laptop computers and TVs, such as inexpensive calculators. In particular, these are used on portable devices where less information content needs to be displayed, lowest power consumption (no backlight) and low cost are desired or readability in direct sunlight is needed.

A comparison between a blank passive-matrix display (top) and a blank active-matrix display (bottom). A passive-matrix display can be identified when the blank background is more grey in appearance than the crisper active-matrix display, fog appears on all edges of the screen, and while pictures appear to be fading on the screen.

Displays having a passive-matrix structure are employing Crosstalk between activated and non-activated pixels has to be handled properly by keeping the RMS voltage of non-activated pixels below the threshold voltage as discovered by Peter J. Wild in 1972,

STN LCDs have to be continuously refreshed by alternating pulsed voltages of one polarity during one frame and pulses of opposite polarity during the next frame. Individual pixels are addressed by the corresponding row and column circuits. This type of display is called response times and poor contrast are typical of passive-matrix addressed LCDs with too many pixels and driven according to the "Alt & Pleshko" drive scheme. Welzen and de Vaan also invented a non RMS drive scheme enabling to drive STN displays with video rates and enabling to show smooth moving video images on an STN display.

Bistable LCDs do not require continuous refreshing. Rewriting is only required for picture information changes. In 1984 HA van Sprang and AJSM de Vaan invented an STN type display that could be operated in a bistable mode, enabling extremely high resolution images up to 4000 lines or more using only low voltages.

High-resolution color displays, such as modern LCD computer monitors and televisions, use an active-matrix structure. A matrix of thin-film transistors (TFTs) is added to the electrodes in contact with the LC layer. Each pixel has its own dedicated transistor, allowing each column line to access one pixel. When a row line is selected, all of the column lines are connected to a row of pixels and voltages corresponding to the picture information are driven onto all of the column lines. The row line is then deactivated and the next row line is selected. All of the row lines are selected in sequence during a refresh operation. Active-matrix addressed displays look brighter and sharper than passive-matrix addressed displays of the same size, and generally have quicker response times, producing much better images. Sharp produces bistable reflective LCDs with a 1-bit SRAM cell per pixel that only requires small amounts of power to maintain an image.

Segment LCDs can also have color by using Field Sequential Color (FSC LCD). This kind of displays have a high speed passive segment LCD panel with an RGB backlight. The backlight quickly changes color, making it appear white to the naked eye. The LCD panel is synchronized with the backlight. For example, to make a segment appear red, the segment is only turned ON when the backlight is red, and to make a segment appear magenta, the segment is turned ON when the backlight is blue, and it continues to be ON while the backlight becomes red, and it turns OFF when the backlight becomes green. To make a segment appear black, the segment is always turned ON. An FSC LCD divides a color image into 3 images (one Red, one Green and one Blue) and it displays them in order. Due to persistence of vision, the 3 monochromatic images appear as one color image. An FSC LCD needs an LCD panel with a refresh rate of 180 Hz, and the response time is reduced to just 5 milliseconds when compared with normal STN LCD panels which have a response time of 16 milliseconds.

Samsung introduced UFB (Ultra Fine & Bright) displays back in 2002, utilized the super-birefringent effect. It has the luminance, color gamut, and most of the contrast of a TFT-LCD, but only consumes as much power as an STN display, according to Samsung. It was being used in a variety of Samsung cellular-telephone models produced until late 2006, when Samsung stopped producing UFB displays. UFB displays were also used in certain models of LG mobile phones.

Twisted nematic displays contain liquid crystals that twist and untwist at varying degrees to allow light to pass through. When no voltage is applied to a TN liquid crystal cell, polarized light passes through the 90-degrees twisted LC layer. In proportion to the voltage applied, the liquid crystals untwist changing the polarization and blocking the light"s path. By properly adjusting the level of the voltage almost any gray level or transmission can be achieved.

In-plane switching is an LCD technology that aligns the liquid crystals in a plane parallel to the glass substrates. In this method, the electrical field is applied through opposite electrodes on the same glass substrate, so that the liquid crystals can be reoriented (switched) essentially in the same plane, although fringe fields inhibit a homogeneous reorientation. This requires two transistors for each pixel instead of the single transistor needed for a standard thin-film transistor (TFT) display. The IPS technology is used in everything from televisions, computer monitors, and even wearable devices, especially almost all LCD smartphone panels are IPS/FFS mode. IPS displays belong to the LCD panel family screen types. The other two types are VA and TN. Before LG Enhanced IPS was introduced in 2001 by Hitachi as 17" monitor in Market, the additional transistors resulted in blocking more transmission area, thus requiring a brighter backlight and consuming more power, making this type of display less desirable for notebook computers. Panasonic Himeji G8.5 was using an enhanced version of IPS, also LGD in Korea, then currently the world biggest LCD panel manufacture BOE in China is also IPS/FFS mode TV panel.

In 2015 LG Display announced the implementation of a new technology called M+ which is the addition of white subpixel along with the regular RGB dots in their IPS panel technology.

Most of the new M+ technology was employed on 4K TV sets which led to a controversy after tests showed that the addition of a white sub pixel replacing the traditional RGB structure would reduce the resolution by around 25%. This means that a 4K TV cannot display the full UHD TV standard. The media and internet users later called this "RGBW" TVs because of the white sub pixel. Although LG Display has developed this technology for use in notebook display, outdoor and smartphones, it became more popular in the TV market because the announced 4K UHD resolution but still being incapable of achieving true UHD resolution defined by the CTA as 3840x2160 active pixels with 8-bit color. This negatively impacts the rendering of text, making it a bit fuzzier, which is especially noticeable when a TV is used as a PC monitor.

In 2011, LG claimed the smartphone LG Optimus Black (IPS LCD (LCD NOVA)) has the brightness up to 700 nits, while the competitor has only IPS LCD with 518 nits and double an active-matrix OLED (AMOLED) display with 305 nits. LG also claimed the NOVA display to be 50 percent more efficient than regular LCDs and to consume only 50 percent of the power of AMOLED displays when producing white on screen.

This pixel-layout is found in S-IPS LCDs. A chevron shape is used to widen the viewing cone (range of viewing directions with good contrast and low color shift).

Vertical-alignment displays are a form of LCDs in which the liquid crystals naturally align vertically to the glass substrates. When no voltage is applied, the liquid crystals remain perpendicular to the substrate, creating a black display between crossed polarizers. When voltage is applied, the liquid crystals shift to a tilted position, allowing light to pass through and create a gray-scale display depending on the amount of tilt generated by the electric field. It has a deeper-black background, a higher contrast ratio, a wider viewing angle, and better image quality at extreme temperatures than traditional twisted-nematic displays.

Blue phase mode LCDs have been shown as engineering samples early in 2008, but they are not in mass-production. The physics of blue phase mode LCDs suggest that very short switching times (≈1 ms) can be achieved, so time sequential color control can possibly be realized and expensive color filters would be obsolete.

Some LCD panels have defective transistors, causing permanently lit or unlit pixels which are commonly referred to as stuck pixels or dead pixels respectively. Unlike integrated circuits (ICs), LCD panels with a few defective transistors are usually still usable. Manufacturers" policies for the acceptable number of defective pixels vary greatly. At one point, Samsung held a zero-tolerance policy for LCD monitors sold in Korea.ISO 13406-2 standard.

Dead pixel policies are often hotly debated between manufacturers and customers. To regulate the acceptability of defects and to protect the end user, ISO released the ISO 13406-2 standard,ISO 9241, specifically ISO-9241-302, 303, 305, 307:2008 pixel defects. However, not every LCD manufacturer conforms to the ISO standard and the ISO standard is quite often interpreted in different ways. LCD panels are more likely to have defects than most ICs due to their larger size. For example, a 300 mm SVGA LCD has 8 defects and a 150 mm wafer has only 3 defects. However, 134 of the 137 dies on the wafer will be acceptable, whereas rejection of the whole LCD panel would be a 0% yield. In recent years, quality control has been improved. An SVGA LCD panel with 4 defective pixels is usually considered defective and customers can request an exchange for a new one.

Some manufacturers, notably in South Korea where some of the largest LCD panel manufacturers, such as LG, are located, now have a zero-defective-pixel guarantee, which is an extra screening process which can then determine "A"- and "B"-grade panels.clouding (or less commonly mura), which describes the uneven patches of changes in luminance. It is most visible in dark or black areas of displayed scenes.

The zenithal bistable device (ZBD), developed by Qinetiq (formerly DERA), can retain an image without power. The crystals may exist in one of two stable orientations ("black" and "white") and power is only required to change the image. ZBD Displays is a spin-off company from QinetiQ who manufactured both grayscale and color ZBD devices. Kent Displays has also developed a "no-power" display that uses polymer stabilized cholesteric liquid crystal (ChLCD). In 2009 Kent demonstrated the use of a ChLCD to cover the entire surface of a mobile phone, allowing it to change colors, and keep that color even when power is removed.

In 2004, researchers at the University of Oxford demonstrated two new types of zero-power bistable LCDs based on Zenithal bistable techniques.e.g., BiNem technology, are based mainly on the surface properties and need specific weak anchoring materials.

Resolution The resolution of an LCD is expressed by the number of columns and rows of pixels (e.g., 1024×768). Each pixel is usually composed 3 sub-pixels, a red, a green, and a blue one. This had been one of the few features of LCD performance that remained uniform among different designs. However, there are newer designs that share sub-pixels among pixels and add Quattron which attempt to efficiently increase the perceived resolution of a display without increasing the actual resolution, to mixed results.

Spatial performance: For a computer monitor or some other display that is being viewed from a very close distance, resolution is often expressed in terms of dot pitch or pixels per inch, which is consistent with the printing industry. Display density varies per application, with televisions generally having a low density for long-distance viewing and portable devices having a high density for close-range detail. The Viewing Angle of an LCD may be important depending on the display and its usage, the limitations of certain display technologies mean the display only displays accurately at certain angles.

Temporal performance: the temporal resolution of an LCD is how well it can display changing images, or the accuracy and the number of times per second the display draws the data it is being given. LCD pixels do not flash on/off between frames, so LCD monitors exhibit no refresh-induced flicker no matter how low the refresh rate.

Color performance: There are multiple terms to describe different aspects of color performance of a display. Color gamut is the range of colors that can be displayed, and color depth, which is the fineness with which the color range is divided. Color gamut is a relatively straight forward feature, but it is rarely discussed in marketing materials except at the professional level. Having a color range that exceeds the content being shown on the screen has no benefits, so displays are only made to perform within or below the range of a certain specification.white point and gamma correction, which describe what color white is and how the other colors are displayed relative to white.

Brightness and contrast ratio: Contrast ratio is the ratio of the brightness of a full-on pixel to a full-off pixel. The LCD itself is only a light valve and does not generate light; the light comes from a backlight that is either fluorescent or a set of LEDs. Brightness is usually stated as the maximum light output of the LCD, which can vary greatly based on the transparency of the LCD and the brightness of the backlight. Brighter backlight allows stronger contrast and higher dynamic range (HDR displays are graded in peak luminance), but there is always a trade-off between brightness and power consumption.

Low power consumption. Depending on the set display brightness and content being displayed, the older CCFT backlit models typically use less than half of the power a CRT monitor of the same size viewing area would use, and the modern LED backlit models typically use 10–25% of the power a CRT monitor would use.

Usually no refresh-rate flicker, because the LCD pixels hold their state between refreshes (which are usually done at 200 Hz or faster, regardless of the input refresh rate).

No theoretical resolution limit. When multiple LCD panels are used together to create a single canvas, each additional panel increases the total resolution of the display, which is commonly called stacked resolution.

LCDs can be made transparent and flexible, but they cannot emit light without a backlight like OLED and microLED, which are other technologies that can also be made flexible and transparent.

As an inherently digital device, the LCD can natively display digital data from a DVI or HDMI connection without requiring conversion to analog. Some LCD panels have native fiber optic inputs in addition to DVI and HDMI.

Limited viewing angle in some older or cheaper monitors, causing color, saturation, contrast and brightness to vary with user position, even within the intended viewing angle. Special films can be used to increase the viewing angles of LCDs.

Uneven backlighting in some monitors (more common in IPS-types and older TNs), causing brightness distortion, especially toward the edges ("backlight bleed").

Display motion blur on moving objects caused by slow response times (>8 ms) and eye-tracking on a sample-and-hold display, unless a strobing backlight is used. However, this strobing can cause eye strain, as is noted next:

As of 2012, most implementations of LCD backlighting use pulse-width modulation (PWM) to dim the display,CRT monitor at 85 Hz refresh rate would (this is because the entire screen is strobing on and off rather than a CRT"s phosphor sustained dot which continually scans across the display, leaving some part of the display always lit), causing severe eye-strain for some people.LED-backlit monitors, because the LEDs switch on and off faster than a CCFL lamp.

Only one native resolution. Displaying any other resolution either requires a video scaler, causing blurriness and jagged edges, or running the display at native resolution using 1:1 pixel mapping, causing the image either not to fill the screen (letterboxed display), or to run off the lower or right edges of the screen.

Fixed bit depth (also called color depth). Many cheaper LCDs are only able to display 262144 (218) colors. 8-bit S-IPS panels can display 16 million (224) colors and have significantly better black level, but are expensive and have slower response time.

Input lag, because the LCD"s A/D converter waits for each frame to be completely been output before drawing it to the LCD panel. Many LCD monitors do post-processing before displaying the image in an attempt to compensate for poor color fidelity, which adds an additional lag. Further, a video scaler must be used when displaying non-native resolutions, which adds yet more time lag. Scaling and post processing are usually done in a single chip on modern monitors, but each function that chip performs adds some delay. Some displays have a video gaming mode which disables all or most processing to reduce perceivable input lag.

Dead or stuck pixels may occur during manufacturing or after a period of use. A stuck pixel will glow with color even on an all-black screen, while a dead one will always remain black.

Subject to burn-in effect, although the cause differs from CRT and the effect may not be permanent, a static image can cause burn-in in a matter of hours in badly designed displays.

In a constant-on situation, thermalization may occur in case of bad thermal management, in which part of the screen has overheated and looks discolored compared to the rest of the screen.

Loss of brightness and much slower response times in low temperature environments. In sub-zero environments, LCD screens may cease to function without the use of supplemental heating.

Several different families of liquid crystals are used in liquid crystal displays. The molecules used have to be anisotropic, and to exhibit mutual attraction. Polarizable rod-shaped molecules (biphenyls, terphenyls, etc.) are common. A common form is a pair of aromatic benzene rings, with a nonpolar moiety (pentyl, heptyl, octyl, or alkyl oxy group) on one end and polar (nitrile, halogen) on the other. Sometimes the benzene rings are separated with an acetylene group, ethylene, CH=N, CH=NO, N=N, N=NO, or ester group. In practice, eutectic mixtures of several chemicals are used, to achieve wider temperature operating range (−10..+60 °C for low-end and −20..+100 °C for high-performance displays). For example, the E7 mixture is composed of three biphenyls and one terphenyl: 39 wt.% of 4"-pentyl[1,1"-biphenyl]-4-carbonitrile (nematic range 24..35 °C), 36 wt.% of 4"-heptyl[1,1"