lcd display fading made in china

SEOUL (Reuters) - Chinese flat screen makers, once dismissed as second-class players in the global LCD market, are drawing envious looks from big names such as LG Display Co Ltd and Samsung.A man walks out of the headquarters of LG Display in Seoul, October 20, 2011. REUTERS/Jo Yong-Hak

While the Korean giants were busy developing next-generation organic light emitting diode (OLED) TVs, little-known Chinese companies have started selling a type of display that are sharper than the standard LCD and cheaper than OLED.

Until last year, the UHD market had been almost non-existent, with just 33,000 sets sold in the 200 million-unit LCD TV market. Since then, shipments have soared around 20-fold, thanks to China, data from research firm IHS shows.

Chinese consumers who want brighter and sharper images but can’t afford OLED screens made by LG and Samsung Display, a unit of Samsung Electronics Co Ltd, are turning to UHD.

But its slow introduction into the market and austere prices have thrown open a window of opportunity for UHD makers, in this case Chinese companies like BOE Technology Group Co Ltd and TCL Corp’s LCD unit CSOT.

“We assumed it’ll be too early for this type of display to take off, and thus didn’t think much of having diverse UHD product line-ups, especially in the low end. But I think we are not late just yet and we are working hard to lead the market here.”

By comparison, Japanese flat-screen pioneer Sharp Corp reported a razor-thin 0.5 percent margin. LG Display, the world’s No.1 LCD maker, posted a 5.6 percent margin.

Samsung Display, a unit of Samsung Electronics, had a margin of 13 percent, the biggest in the industry. But excluding its fledging OLED business, its LCD margin is between 3 and 7 percent, according to a Bernstein forecast.

Jolted by the reality of a growing UHD market, Samsung Electronics unveiled a 110-inch UHD TV in January. Interestingly, the UHD displays were not made by Samsung Display, but were produced by Taiwan’s AU Optronics.

“Even with some expansion of the Chinese panel suppliers we do expect Samsung and LG Display to stay dominant and continue production in LCD,” said Sweta Dash, director at IHS.

While Samsung and LG Display are investing billions of dollars in OLED this year, the two giants are also broadening their product lineups to include more popular 50 to 60-inch UHD models.

BOE Technology is now planning to raise 46 billion yuan ($7.5 billion) in the biggest Chinese equity offering this year, to build panel production lines and increase its stake in its LCD venture BOE Display Technology.

I"m using this (https://smile.amazon.com/gp/product/B07 ... UTF8&psc=1) 4 line LCD display. Does this type of display have a problem with burn in or anything like that? I"m trying to decide if I need to limit the time the display is on or if I can leave it on 24/7.

LCD panels will fade with time, but the device is likely to last a decade or more before you notice the fade, at least speaking from personal experience with monitors that are on 24/7 for the last decade at my place of employment.

One widely cited problem is that OLED displays don"t last as long: degradation of the organic molecules meant that early versions of OLEDs tended to wear out around four times faster than conventional LCDs or LED displays. Manufacturers have been working hard to address this and it"s much less of a problem than it used to be.

There are a lot of tricks that OLED TVs (and presumably mobile phones) are documented as doing to reduce the wear on OLED pixels, such as "resting" individual pixels by subtly dimming some whilst brightening adjacent ones and applying slight blurs or colour changes where lack of detail won"t be noticed. For example the whole "reduce blue light in the evening because it helps you sleep" colour shift may well be a chance for the display to give the blue OLED pixels a bit of a break as much as anything else

Traditional LCD display"s like you linked will work for many decades as long as they are not in direct sunlight and kept between 15°C and 40°C at less than 90%RH. Other environmental conditions can shorten the life span significantly. The LED"s used for backlighting, when used at moderate brightness, will also be usable for decades before dimming is noticeable.

The small inexpensive OLED displays do burn out rather quickly compared to other technologies. This statement from Adafruit for one they sell is dead on IME. https://www.adafruit.com/product/326

Please note that OLED displays are made of hundreds of...OLEDs! That means each pixel is a little organic LED, and if it"s kept on for over 1000 hours it"ll start to dim. If you want to keep the display uniformly bright, please turn off the display (set the pixels off) when it isn"t needed to keep them from dimming.

Wish I"d known that before I put my one OLED project into service (bought the OLED from eBay), in under two months the display started to get rather ugly with many pixels at varying brightness levels. Fortunately, after over two years with the display on continuously it hasn"t gotten too much uglier and it is still readable.

Those OLEDs aren"t designed for 24x7 operation and will degrade rapidly if left continuously on. They"re meant for cordless phones where the display is usually off. The yellow strip at the top is for a status bar.

As an aside, if you can remove the transparent polarizing bezel from the front of the display, and re-install it back to front, then you end up with white digits on a black background. I used to customise calculators for folk when I was in high school doing that.Post Comment

Resolution: Faded or incomplete segments indicate a poor connection between the LCD and the circuit board. To remedy, clean the LCD, the circuit board and the rubber elastomers that make the connections. Using isopropyl (rubbing) alcohol on a cotton swab, do the following:

If cleaning the monitor does not improve the display, an upgrade to a PM5 monitor will be needed. Replacement LCDs are no longer available for PM2/PM2+ Performance Monitors. The PM5 Monitor Retrofit Kit is available from Concept2.

(Bloomberg) -- Japan Display Inc., once one of Apple Inc.’s key suppliers, sees a new market for its liquid crystal displays after ceding the smartphones arena to rival OLED screens: the niche yet growing virtual reality business.

The Tokyo-based LCD specialist expects its favored display technology to become the standard for VR because it can achieve higher resolution than OLED while keeping costs reasonable. That advantage is imperceptible in mobile devices but becomes critical in the more demanding VR scenario.

Many of the first wave of headsets released five years ago used OLED screens -- or organic light-emitting diodes, the same as used across most flagship phones today -- for their responsiveness to fast-moving action, a common feature of gaming experiences. But major players such as HTC Corp. and Facebook have moved to LCDs for their latest products, betting on the more economical standard to improve the user experience and immersion. Industry researchers at Omdia saw LCD adoption rise in 2020 and forecast the technology will dominate the category over the next five years.

One important holdout remains: Sony Group Corp. plans to use Samsung Display Co. OLED panels in its next-generation PlayStation VR goggles, according to people with knowledge of the matter. The Japanese console giant sold more than 5 million units of the original PS VR, launched in 2016, and is aiming to release the successor in the holiday period next year, the people said, asking not to be named discussing internal plans.

To grab a bigger share of the market, JDI is working to convince VR companies it can solve two of their biggest hurdles: display quality and cost. Because VR goggles place the screen so much closer to the human eye, they require higher resolution and clarity than mobile screens, achieved by packing pixels closer together. JDI is capable of producing displays with 1,200 pixels per inch, more than double the typical density of top-tier phone panels, according to its chief VR headset engineer, Yoshihiro Watanabe.

The threshold for a high-quality VR experience is to have a display with at least 1,000 pixels per inch, Watanabe said, adding that JDI is one of the few display makers -- if not the only -- that can mass-produce such panels at a reasonable production yield.

JDI was created in 2012 by the combination of the display-making units of Sony, Hitachi Ltd. and Toshiba Corp., with much of its revenue since then coming from mobile handsets, especially iPhones. More than half of its total sales used to come from the Apple business, but the iPhone maker’s adoption of OLED technology left the company reeling.

Unable to develop its own OLED panels to a competitive level with leader Samsung Display, JDI has seen its revenue from phones drop from 838 billion yen ($7.7 billion) in the year ended March 2016 to an expected 81 billion yen this fiscal year. The firm sold the factory it had used mainly to produce panels for Apple to Sharp Corp. last year.

It’s difficult to say that LCD is in all cases superior to OLED for VR, Hayase said, because OLED offers better contrast in addition to faster response times. The key for JDI will be to establish a solid footing in the industry by addressing customer needs that other suppliers would turn down owing to the small market size, he added. JDI has experience of doing that from its business supplying display panels for digital cameras.

BMW 3 series (E36), 5 series (E34, E39), 7 series (E38), 8 series (E31), X5 from 1988-2003 all have the common dead / fading / disappearing pixels on the dashboard instrument cluster / speedometer (also on the board computer) - on the large LCD display that shows valuable data such as the mileage and the on board computer messages. The LCD display pixel problem lies with the OBC ribbon cable that connects the LCD display to the circuit board of the instrument cluster. The pictures below show the speedo / instrument cluster"s LCD display before and after the silver ribbon cable KIT replacement (just an example of several board computer / dashboard instrument cluster types):

The instrument cluster units in the BMW E38, E39 and X5 models from 1994-2003 are quite similar - (they were all produced by Siemens VDO) - using the same LCD and the same ribbon cable at all models. There are minor differences, like diesel or petrol powered ones, and also some speedos come with miles others with km/hrs, however the OBC LCD display and the ribbon cable is the same at all 5 series (E39) 7 series (E38) and X5 (E53) and M5 models.

The OBC unit on the MID console - also known as radio / telephone unit on BMW E39, X5, M5 models from 1996-2003 are identical, using the same OBC LCD and the same ribbon cable. There are minor differences, like one comes with telephone button, others are witout, however the LCD display and the ribbon cable is the same at all 5 series (E39) X5 (E53) and M5 models.

Fits all E39 / E53 MID units assembled with bulbs (not leds). If you have uneven background light on the MID unit (some parts of the LCD are lighter, some are darker), most probably you have dead or almost dead bulbs.

The OBC unit on the MID console - also known as radio / telephone unit on BMW E38 from 1994-2003 have the very common fading or missing pixels, lines, columns.

Fits all BMW E38 7 series A/C (air conditioning) climate control units assembled with 2 small LCD"s - just like the one on the picture. Essential for dead or fading pixel repairs.

BMW 8 series (E31), from1988-1999 all have the common disappearing/fading pixels on the on board computer LCD. The problem lies with the ribbon cable that connects the LCD display to the circuit board of the MID.

BMW 3 series (E36), from1988-1999 all have the common disappearing / fading or completely dead LCD pixels on the board computer display. The problem lies with the ribbon cable that connects the LCD display to the circuit board of the MID. All 3 variants (8 / 11 / 16 buttons) are available.

This is a very common failure at BMW E90, E91, E92 BMW CD73 stereo / radio / head units, that the central display has missing lines and columns, missing and fading pixels all around the LCD display.Most common at BMW 3 series E90, but E91 E92 and other models are also affected.

This is a very common failure at BMW E90, E91, E92 BMW CD73 stereo / radio / head units, that the central display has missing lines and columns, missing and fading pixels all around the LCD display.

If your display is leaking, suffers from pixel issues (one or more pixels, or complete lines are missing), or completely dead, then this KIT will NOT help, this case please do not buy it!

This is a very common failure at BMW Bavaria radio units, that the display has missing lines and columns, missing and fading pixels all around the LCD display.

Why do the BMW speedometer LCD displays fail with pixel failure? DIY Pixel repair helps with pixel failure? Well the BMW speedo manufacturers have a few minurtes only to produce a complete BMW speedo with LCD dispay and silver. Because of this, VDO Instrument Cluster manufacturer decied to assemble the BMW LCD display and the silver ribbon cable with heat bonding procedure. This BMW speedometer assembly design makes the contacts of the LCD display and the ribbon cable loose contact very fast, most cases in just a few years. This means, the BMW LCD display show pixel failures, it needs pixel repair, but both the silver ribbon cable and the BMW LCD display work well - only the connection of them is bad, tha is why you have LCD display pixel problems, and you need a pixel fix by a professional, or done DIY with an LCD display pixel repair KIT - a silver cable. How can we improve the quality of the LCD displays and the ribbon cables? Well if you assemble the LCD with the ribbon cable with pressure, no heat bonding, then the pixels of the BMW LCD display will work for an unlimited time. Dashboard LCD displays work on high temperature, so it is the best to avoid using the heat bonding procedure. Pixel repair DIY, or pixel fix by a professional?

The LCD display repair ribbon cable KIT is available in silver cable version. Once the BMW dashboard instrument cluster LCD display pixel failure was properly repaired, the BMW speedometer display will work as new, the silver ribbon cable and the LCD will work for good in the speedometer.

- If the bulbs are out behind the display, then all the rows and colunms do work on the BMW speedometer LCD display, but the background light of the LCD display is uneven, or some cases the BMW LCD display is completely dark. This case no need to repair the pixels, you do not need a silver or carbon ribbon cable, nor a new LCD display. This case you just need to buy the lightbulbs that provide light behind the BMW LCD display.

- If the BMW speedometer LCD display has really pixel problems, then typically lines or colunms of the display are missing. Several cases the characters are broken, numbers and letters shown on the speedometer display are unreadable - tha backlight is even. In case of a real pixel problem, when one or more pixels are missing from the display, you need to buy a silver ribbon cable, a carbon ribbon cable, or some cases a complete BMW LCD display. It really depends on that if it is a BMW, a Mercedes, and Audi, Saab or other make, and of course if it a MID display, a speedometer, a board computer or other LCD dipslay. Most cases, when you have a pixel failure, and you decide to repair it, it"s really worth to buy a set of bulbs too, as bulbs tend to go out during repair - this is due to the massive mechanical shocks experienced during the pixel repair procedure.

Well, most of the BMW pixel repair KITs we sell are designed to be simple and easy to use. The word easy should now be the subject of further discussion. An average BMW speedometer LCD display pixel repair is far more difficult then replacing a lightbulb. You definitely have to have good mechnical skills, and some household tools, such as nippers, screewdrivers, household tape, and other goodies to fix things around the house.

If you have to ask one of these questions, then you definitly should NOT do a BMW speedometer LCD display pixel repair at home (we were asked these questions before, this is not a joke):

Well, Pixelfix is an internationally registered trademark. Pixelfix only sells the highest quality BMW speedometer silver ribbon cables, that are capable of lifetime operation. We sell most of our repairs with lifetime warranty, and you will find the exact same displays, cables, and other spare parts that we use for professional repairs. The silver ribbon cables we use for BMW E38 E39 M5 X5 LCD display pixel repair are real silver, which is a very expensive base material, that is why the price is much higher compared to carbon ribbon cables.

You may keep an eye on your package, if you ordered the BMW LCD dispaly with postal delivery on you may check the status on your local post office"s website, or if you ordered next day deliver then you need to see TNT / FedEx or DHL tracking site for status.

All BMW LCD displays, ribbon cables, BMW speedometer spare parts bought in the webshop will come with an invoice. All invoices are issued electronically, so you will receive an e-mail with the printable invoice in it. This invoce can be printed and filed to the accounts.

No worries, we do provide technical support, and help repairing of your BMW speedometer LCD display. We have been repairing these BMW display units for years, we made hundreds of BMW speedometer repairs, so we can provide tecnical support very effectively - on the phone, via skype, via e-amil or whichever you prefer. Please note that you need to book an appointment, but it is completely free of charge.

No worries, this symptom can be due to a bagatel problem which is easy to fix. If there are no pixels on the BMW instrument cluster"s display at all, that MUST be due to one of the followings:

Let"s talk about the worst case scenario, you started the repair, but you do not seem to deal with the repair of the BMW instrument cluster"s display. This case we have a backup solution. We always stand behind our customers, so you may send the BMW speedometer LCD display unit to us for repair, and no matter what the condition of the unit is, we can help. More precisely, up to this point we always succeeded, meaning none of our customers managed to do such a damage in the unit that we could not fix. The repair does not cost a fortune, in a lucky case it is 20-30 Euro plus return delivery cost only.

LCD manufacturers are mainly located in China, Taiwan, Korea, Japan. Almost all the lcd or TFT manufacturers have built or moved their lcd plants to China on the past decades. Top TFT lcd and oled display manufactuers including BOE, COST, Tianma, IVO from China mainland, and Innolux, AUO from Tianwan, but they have established factories in China mainland as well, and other small-middium sizes lcd manufacturers in China.

China flat display revenue has reached to Sixty billion US Dollars from 2020. there are 35 tft lcd lines (higher than 6 generation lines) in China,China is the best place for seeking the lcd manufacturers.

The first half of 2021, BOE revenue has been reached to twenty billion US dollars, increased more than 90% than thesame time of 2020, the main revenue is from TFT LCD, AMoled. BOE flexible amoled screens" output have been reach to 25KK pcs at the first half of 2021.the new display group Micro LED revenue has been increased to 0.25% of the total revenue as well.

Established in 1993 BOE Technology Group Co. Ltd. is the top1 tft lcd manufacturers in China, headquarter in Beijing, China, BOE has 4 lines of G6 AMOLED production lines that can make flexible OLED, BOE is the authorized screen supplier of Apple, Huawei, Xiaomi, etc,the first G10.5 TFT line is made in BOE.BOE main products is in large sizes of tft lcd panel,the maximum lcd sizes what BOE made is up to 110 inch tft panel, 8k resolution. BOE is the bigger supplier for flexible AM OLED in China.

As the market forecast of 2022, iPhone OLED purchasing quantity would reach 223 million pcs, more 40 million than 2021, the main suppliers of iPhone OLED screen are from Samsung display (61%), LG display (25%), BOE (14%). Samsung also plan to purchase 3.5 million pcs AMOLED screen from BOE for their Galaxy"s screen in 2022.

Technology Co., Ltd), established in 2009. CSOT is the company from TCL, CSOT has eight tft LCD panel plants, four tft lcd modules plants in Shenzhen, Wuhan, Huizhou, Suzhou, Guangzhou and in India. CSOTproviding panels and modules for TV and mobile

three decades.Tianma is the leader of small to medium size displays in technologyin China. Tianma have the tft panel factories in Shenzhen, Shanhai, Chendu, Xiamen city, Tianma"s Shenzhen factory could make the monochrome lcd panel and LCD module, TFT LCD module, TFT touch screen module. Tianma is top 1 manufactures in Automotive display screen and LTPS TFT panel.

Tianma and BOE are the top grade lcd manufacturers in China, because they are big lcd manufacturers, their minimum order quantity would be reached 30k pcs MOQ for small sizes lcd panel. price is also top grade, it might be more expensive 50%~80% than the market price.

Established in 2005, IVO is located in Kunsan,Jiangshu province, China, IVO have more than 3000 employee, 400 R&D employee, IVO have a G-5 tft panel production line, IVO products are including tft panel for notebook, automotive display, smart phone screen. 60% of IVO tft panel is for notebook application (TOP 6 in the worldwide), 23% for smart phone, 11% for automotive.

Besides the lcd manufacturers from China mainland,inGreater China region,there are other lcd manufacturers in Taiwan,even they started from Taiwan, they all have built the lcd plants in China mainland as well,let"s see the lcd manufacturers in Taiwan:

Innolux"s 14 plants in Taiwan possess a complete range of 3.5G, 4G, 4.5G, 5G, 6G, 7.5G, and 8.5G-8.6G production line in Taiwan and China mainland, offering a full range of large/medium/small LCD panels and touch-control screens.including 4K2K ultra-high resolution, 3D naked eye, IGZO, LTPS, AMOLED, OLED, and touch-control solutions,full range of TFT LCD panel modules and touch panels, including TV panels, desktop monitors, notebook computer panels, small and medium-sized panels, and medical and automotive panels.

AUO is the tft lcd panel manufacturers in Taiwan,AUO has the lcd factories in Tianma and China mainland,AUOOffer the full range of display products with industry-leading display technology,such as 8K4K resolution TFT lcd panel, wide color gamut, high dynamic range, mini LED backlight, ultra high refresh rate, ultra high brightness and low power consumption. AUO is also actively developing curved, super slim, bezel-less, extreme narrow bezel and free-form technologies that boast aesthetic beauty in terms of design.Micro LED, flexible and foldable AMOLED, and fingerprint sensing technologies were also developed for people to enjoy a new smart living experience.

Hannstar was found in 1998 in Taiwan, Hannstar display hasG5.3 TFT-LCD factory in Tainan and the Nanjing LCM/Touch factories, providing various products and focus on the vertical integration of industrial resources, creating new products for future applications and business models.

driver, backlight etc ,then make it to tft lcd module. so its price is also more expensive than many other lcd module manufacturers in China mainland.

Maclight is a China based display company, located in Shenzhen, China. ISO9001 certified, as a company that more than 10 years working experiences in display, Maclight has the good relationship with top tft panel manufacturers, it guarantee that we could provide a long term stable supply in our products, we commit our products with reliable quality and competitive prices.

Maclight products included monochrome lcd, TFT lcd module and OLED display, touch screen module, Maclight is special in custom lcd display, Sunlight readable tft lcd module, tft lcd with capacitive touch screen. Maclight is the leader of round lcd display. Maclight is also the long term supplier for many lcd companies in USA and Europe.

If you want tobuy lcd moduleorbuy tft screenfrom China with good quality and competitive price, Maclight would be a best choice for your glowing business.

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 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.

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.

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.

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.

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 (nitri