can a lcd screen be repaired made in china

Mandy, ETS is obviously a company that you are connected to and this could easily be taken for spam. I think we can make an exception at this time since you are asking a good market research question that may be useful to many.

Having checked out your video, I personally will not use the aftermarket screen as a replacement for my X. It just doesn"t have what I expect for a $1000 USD phone. I recognize that $300 USD for a replacement is hefty but the aftermarket screen does not appear to have the quality that I would expect for my phone.

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Maybe your significant other tossed your phone off the balcony after discovering flirty texts with a certain coworker, or maybe you were just blackout drunk and dropped your phone on the club’s tile washroom floor while taking a shameless mirror selfie. Either way, your mobile’s glass screen likely looks like a drunken spider’s web.

Luckily for you, smartphone repairs in China are both affordable and fast. But before you venture off to your city’s electronics sales and repair market, we encourage you to browse these six helpful tips for repairing your phone screen:

As with damage to just about any electronic product, knowing the extent of the destruction will go a long way towards ensuring your trusty repairman doesn’t try and pull a fast one by over-quoting or overstating the damage.

In the case of phone glass and the LCD – or more recently AMOLED – screen underneath, it helps to know whether just one, or both, of these elements needs replacing (particularly so you can better estimate the cost).

While broken glass on the front of your mobile is obvious and easy to diagnose, a damaged screen (the part that actually displays all the programs and interface) can be a bit trickier to identify. Look for black spots, discolored areas, new lines and out-of-place patterns on your screen, as any of these may indicate a problem with the screen. Naturally, a totally black screen is a pretty good indicator that something is amiss.

One way to test your screen is to hold down on an app on your phone’s ‘desktop area’ until it starts vibrating, allowing you the move the app to new locations on your screen. Move the app to all parts of your display, if the app is unable to reach a certain area, this is a good indication that you’ll be fixing more than just broken glass.

From our experience, this may very likely be the most important step of all. When having your device"s screen or glass fixed, be sure to show the person doing the repair that all of its key components are in working order. In particular, be sure to demonstrate that both your front and rear cameras work, as well as the speaker and microphone.

We cannot count how many times we have heard of a phone being returned after a repair only for the owner to discover that the phone’s microphone (key for, you know, speaking on the phone) or cameras are no longer working. Also from experience: most repair people are unlikely to take your word that your camera was fine before you handed it over to them.

This should probably go without saying, but here we go anyway: having your mobile device repaired by someone other than a company technician from your phone’s particular brand will likely (like basically 100 percent) result in your warranty being voided.

Not every repair shop will give you the option of watching your phone’s crushed glass be replaced. This is because many smaller shops, particularly in electronics markets, will have your phone sent to an offsite repair area and tell you to come back in a few hours to collect it.

If possible, try and find a shop that will complete the repair in front of you. The main reason we encourage this is because we have heard several unfortunate stories where costumers have had their fully-functioning phone battery swapped out for one that can only hold a two-hour charge. Sad!

The price of having your phone’s glass or LCD screen replaced will depend greatly on the make and model of your phone, the honesty of the person fixing it and – like all things in Asia – your bargaining skills. If your local smartphone repair person wants RMB300 to replace your iPhone 6’s shattered glass, lowball them and offer RMB150. From our experience, repair people seem more inclined to budge on price when it comes to older model phones, meaning your brand new iPhone Xs Plus or Huawei P20 will likely have a higher price point and less discount wiggle-room.

Finding a good repair shop with honest staff who do repairs at a high quality and reasonable price can sometimes be difficult. If you manage to track down a good phone-fixing location, be sure to recommend it to your friends to save them the potentially costly and annoying trial-and-error process when having their glass or screen replaced.

Have you got countless broken screens with a LCD that still works? All over the world, broken screens are bought by various Buyback suppliers. These broken LCD’s are the raw materials for refurbished screens. But what actually happens to a broken screen? In part 1 of the Buyback and OEM Refurbished series, we tell you all about the process of how Buyback screens become OEM Refurbished screens and explain which grades of quality there are in the market.

To begin with, most purchased screens are sent to Hong Kong. From Hong Kong, the screens are sold to Chinese dealers who have their own shop on the electronic market in Shenzhen. The Chinese dealers transport the screens to Shenzhen.

In Shenzhen, the broken screens are bought up by manufacturers. These are manufacturers that are specialised in refurbishment. New glass plates are mounted on the LCD’s and if necessary, the backlight and polariser are replaced. After the screens have been repaired, the refurbished screens are sold again to Chinese dealers who have their own shop at the electronic market in Shenzhen.

Our sourcing team in Shenzhen buys custom-made OEM Refurbished LCD’s with the desired materials. These materials are selected by our specialists and then offered to manufacturers that assemble the screens. We are also supplied by our own Buyback programme (buybackLCD.com), in which we are very strict as to which quality of donors we purchase, because this greatly determines the final quality of the OEM refurbished display. If we buy screens in our own Buyback programme that do not meet our quality requirements, we do not use them for our own OEM refurbished quality. We simply sell these screens in China.

Our team in China is very well aware of which manufacturer is specialised in refurbishing which model per specific iPhone series. Some factories, for instance, are specialised in the 6 series and others in the 7 series. Therefore we make distinctions between which factory we choose. We hand in the donors, pay a refurbishment fee and after a double test carried out by our controllers, we get the OEM refurbished displays back. These screens are sent to our warehouse in the Netherlands and are ready to be sold again!

When someone buys refurbished screens, he/she will begin by grading the quality of the screen. In China, there are five different grades of quality on which the prices depends. Naturally, the end user doesn’t want to pay the same price for an LCD with dead pixels as for a perfectly functioning screen. The worse the cosmetic damage, the less consumers want to pay for the screen, and the price of a Buyback screen depends on this. For this reason, the same grading applies to both Buyback and OEM refurbished screens.

Other specific abnormalities in various models. For instance, special attention is paid to OLED screens for the iPhone X series, considering the seriousness of the cracks in the screen. If the screen is too badly broken, the LCD (soft OLED) can crease and the touch function might become defect after refurbishment.

During the refurbishing process, a number of screens always breaks. And not a single manufacturer on the market can make all A quality Buyback screens to perfection. This is because during checks, some hidden defects are not revealed. This could, for instance, be dead pixels that are under a crack and which only be visible after refurbishment. Sometimes, dirt also gets between the glass or the polariser during the refurbishment process. Usually, a manufacturer is able to repair 50 to 60 percent of the actual A quality Buyback screens which are bought.

In addition to the grading, prices are also based on supply and demand. If the demand is greater than the supply, prices will rise. However, the demand for OEM refurbished screens has decreased due to the arrival of the China copies. As a result, the price you get back for a Buyback screen has also dropped.

If your phone has image display issues, an unresponsive touch screen or physical cracks or scratches on the glass, this LCD and touch screen assembly is what you need

This is not an easy job for someone who has no technical skills with Disassembling or Assembling Cellphones/mobile phones, so only purchase this item if you know how to install it

Highly recommend professional installation. We will not be held responsible for any damages to your cellphone/mobile phone that you may cause during the changing of replacement parts

Since the iPhone 7/7 Plus has been released for quite a long time, finally the China made iPhone 7/7 Plus screen replacementscame out in the market. we’ve got some iPhone 7 series LCD screen replacements samples and done some tests on them, now let’s take a closer look at these new iPhone 7 series LCD screen replacements!(TianmaandLGsources for testing)

After installing all the sample screens to the iPhone 7/7 Plus rear housing assembly, we found that all the China made iPhone 7 series screen replacements are fitting well just like the original ones - the home button fits well, the screen assembly and the rear housing also fits well.

From the picture below, we can see that there is no difference between the China made iPhone 7 series display and the original ones, however, back to the rear side, we can easily figure out which one is which, cause the original one has Apple logo on it while the China made screen has none.

By comparing these two iPhone 7 screens, we can find that the screen flex cables are much different, there are extra IC on the China-Made iPhone 7 screen while the original one has none. And the original iPhone 7 series screen flex cable is integrated together while on the China-Made iPhone 7 series screen the touch function flex cable is soldered to the display and 3D touch flex cable.

Another difference between the original and China made iPhone 7 screen replacements is the exposed IC on the after-market iPhone screen, just like other China-Made iPhone 5 or 6 series screen replacement, which has more potential risk of electrostatic damage and more likely to get damaged and this problem needs to be improved.

During our test, we found that the display color between our after-market iPhone 7 screen and original screen seems a little different although they are not effecting the touch function. And to be honest, there may have some black dots on the screen because of impurities within the screen module when laminating the LCD and backlight together, without any doubt, this can be solved with technical improvement.

The screen touch sensitivity is another big concern for all of us, luckily, during our test, almost all home button and touch functionality on both iPhone 7 and 7 Plus works well, except one piece of iPhone 7, the 3D touch function is not acting so well on the central part of the screen.

The China-Made iPhone 7 series LCD screen assembly replacement still remains to be improved in quality and performance compared to the original ones, the exposed IC, heavier screen flex cable ribbon, and the screen color difference, the touch function stability, although the price is attractive. However, the China made iPhone 7 series screen replacement is under the improvement, and sooner or later their quality and performance can be quite close to original ones and acceptable, if you"re going to stock up some non-original iPhone 7 series LCD screen replacement, pay more attention and we’ll keep you updated with further information about after-market iPhone 7 series screen replacement!

China, we’re told, can make anything. If you need some PCBs in a few weeks, there are a few factories in China that will do it. If you need a nuclear reactor, yep, there’s probably a factory in China that’ll do it because nuclear reactors are listed as one of the items facing new tariffs when imported into the United States. No, I am not kidding. What about LCDs? What about old-school character LCDs? Is it possible to find a factory in China that will make you the LCD you want? That’s what [Robert Baruch] will find out, because he’s repairing an old computer with new parts.

The object of this repair and restomod is a TRS-80 Pocket Computer (PC-1), otherwise known as the Sharp PC-1211. It looks like a calculator, but no, it’s a legitimate computer you can program in BASIC. [Robert] bought this computer for a bit more than $5 on eBay ‘for repair’, which means the zinc-air battery was dead, and unfortunately, the LCD was shot. The LCD technically works, but it just doesn’t look good. Sometime in the last thirty years, moisture got in between the layers of glass, polarizing film, and liquid crystal. This is not unique to [Robert]’s unit — a lot of these PC-1s have the same problem, many of these broken seals rendering the computers themselves useless.

This is an ancient computer, and replacements for this LCD are impossible to find, but because the Sharp PC-1211 is well documented, it is possible to find the datasheet for the original display. With that, it’s just a question of finding an LCD manufacturer that will do it. So far, the costs look good — $800 USD ($300 for tooling and 10 samples, $500 for another 200 LCDs) is what it’ll take to get a few units. [Robert] already has a few people interested in repairing their own Pocket Computers. You can follow the eevblog thread here, or check out the video below.

Use our “Get an Estimate” tool to review potential costs if you get service directly from Apple. The prices shown here are only for screen repair. If your iPhone needs other service, you’ll pay additional costs.

If you go to another service provider, they can set their own fees, so ask them for an estimate. For service covered by AppleCare+, your fee per incident will be the same regardless of which service provider you choose.

Your country or region offers AppleCare+ for this product. Screen repair (front) is eligible for coverage with a fee by using an incident of accidental damage from handling that comes with your AppleCare+ plan.

The Apple Limited Warranty covers your iPhone and the Apple-branded accessories that come in the box with your product against manufacturing issues for one year from the date you bought them. Apple-branded accessories purchased separately are covered by the Apple Limited Warranty for Accessories. This includes adapters, spare cables, wireless chargers, or cases.

Depending on the issue, you might also have coverage with AppleCare+. Terms and Conditions apply, including fees. Feature availability and options may vary by country or region.

We guarantee our service, including replacement parts, for 90 days or the remaining term of your Apple warranty or AppleCare plan, whichever is longer. This is in addition to your rights provided by consumer law.

Replacement equipment that Apple provides as part of the repair or replacement service may contain new or previously used genuine Apple parts that have been tested and pass Apple functional requirements.

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“Original” screens are those containing LCDs manufactured for Apple. “Copy” screens are compatible replacements entirely designed and manufactured by third-party companies not associated with Apple.

LCD display panel can have poorer resolution (i.e. looks “coarser”), worse brightness, contrast and vibrancy and reduced refresh rate amongst other problems.

Changes in specification from original can result in battery and performance issues. Certain badly-engineered screens could even damage the backlight circuitry.

Customers who bring their iPhones to us for a screen repair are offered two choices of replacement- an original or a “copy” screen. The most common response is “Is there a difference- and which one would you recommend?”

Originals are those screens containing LCDs that were manufactured for Apple. So-called “copy” screens are compatible replacements, but designed and manufactured entirely independently by third-party companies, typically in China.

Our answer is simple- the original screen is the one we’d go for ourselves, every time. Some people think we make more money on them, but this isn’t the case. We recommend originals because they’re far higher quality and the price difference is fairly small.

We’d rather only fit original screens. The only reason we don’t is that many people will shop around and choose purely on price. As such, we need to offer the cheaper copy screens to remain competitive and avoid losing these customers. In some cases, they didn’t even know there was a difference in the first place- especially since it’s not in some shops’ interest to draw people’s attention to the issue!

This may well be the worst copy screen we’ve ever come across. As a result, the unfortunate customer has ended up paying twice to have their screen replaced- we’re sure that had they been properly informed, they would have chosen an original in the first place.

While the difference in price between copies and originals can vary across devices, it’s generally around £10 – £14 extra to have an original screen fitted. This really isn’t a lot considering the improved quality and reliability.

We compare our prices to our competitors- and we know that we come out of it favourably. While we have to offer copy screens to remain competitive, we always advise customers to go for the original.

When you’ve spent- directly or indirectly- several hundred pounds for an iPhone with a Retina display, it doesn’t make sense to replace it with a lower-quality screen that can make a £400 phone look like a £40 one! Not only that, but you’re likely to have fewer issues, and a longer-lasting screen.

There’s nothing stopping any random person without training or experience opening up a smartphone repair shop. As a result, the industry is full of companies with little skill or experience who are only interested in getting hold of your money and installing the cheapest parts they can find.

Many- if not most- don’t even acknowledge the existence of copy screens, let alone explain the difference to the customer. Hardly in their interest to do so if they only fit cheap, low-quality copies. Some of them can hardly be blamed- they know so little, they’re not even clear on the differences between OEM, non-OEM and copy displays themselves! Others can be more deliberately misleading… and some outright lie.

Generally, these shops are looking for the cheapest price on replacement screens.. When offered a copy at a half or a third of a price of the original, they’re going to go for that. That might be fine if they offered the customer a cheaper price- what we disagree with is selling “supermarket beans” (i.e. the copy screens) at “Heinz beans” prices!

Heading towards the “blatantly fraudulent”, we’re aware of companies that shamelessly fit copy screens while claiming them to be original. Worse, they’ll take your broken original screen and sell that to a recycler for more than they paid for your copy!

Obtained or manufactured “off the clock” via the same production line that produced them for Apple- in some cases, from the stockpile of parts that didn’t meet Apple’s standards, or

Apple tightened up their supply chain around 2015, which reduced the number of screens available for repairs and increased their price dramatically. A lot of companies went bankrupt, and Chinese manufacturers responded by making their own “copy” screens from scratch. At first, these weren’t much cheaper than the Apple ones, but the price soon fell.

We should be clear that- despite the name- “copy” screens aren’t direct copies of the Apple originals. Rather, they’re compatible replacements that have been designed from scratch and- as a result- vary in some respects that have an effect on usability and quality.

One of the most important differences between an original and a “copy” screen is how the digitizer (touch sensor) is designed. Apple has it manufactured as part of the LCD itself, whereas the copies have it on the glass.

Although there are only a small number of manufacturers of the bare LCDs themselves, these are then bought by countless other companies who add the remaining components needed to turn these into a complete working screen. As a result, you could easily end up with an LCD from the best “copy” manufacturer, but the digitizer/touch (as part of the separately-manufactured glass) from the worst.

There are countless digitizers out there, and you can only take the supplier’s word that the quality is good. Many ship good ones at first, then switch to cheaper parts to make more profit. This is particularly bad with the iPhone 6S and 6S+, since Apple moved the chips responsible for touch processing onto the LCD itself. As a result, you’re not just getting a copy screen- you’re getting copy chips too.

The performance specification (power drain, etc.) of most copy screens isn’t identical to the originals. As a result, they can drain the battery more quickly and mislead the operating system which was optimised for the original screen design.

It’s even possible that this mismatch could damage your backlight. We do a lot of subcontracted repairs for less-experienced shops, and get backlight repairs in almost every day. We’ve had cases where we fixed the circuit, fitted the new copy screen to test it, and had it break the circuit again!

Copy screens can disrupt the touch ID fingerprint reader. With the 6S, 6S+, 7 and 7+, the home button- part of the 3D touch- is part of the screen assembly. Frequently the home button flexes on aftermarket designs don’t work properly and stop the touch ID working- annoying if you use it to unlock the phone or log in to your bank.

We’ve seen many lift away from the frame that holds them in place. This usually results in the flex cable getting torn, and the screen needing replacing. You don’t even need to have dropped the phone- this often happens through general everyday wear and tear.

That brings us to another major issue with the copies. When you drop an Apple original, the glass often breaks, but if the LCD itself is intact, you can continue to use it until it’s fixed. With the copies, the touch/digitizer is on the glass and stops working when that’s broken. Even worse, the LCD itself is more likely to break due to the thinner and more fragile glass.

We’re not convinced this will happen, since Apple recently changed their repair policy to accept iPhones with third-party screens. However, it is possible that copy screens could be stopped from working via an iOS update, since those make a number of security checks.

Chemicals leaking from millions of computer screens in homes, offices and schools could damage human health, according to research by Chinese scientists.

Chemistry professor Su Guanyong and colleagues at Nanjing University of Science and Technology in eastern Jiangsu province studied more than 360 types of chemicals used in computer and mobile phone screens and found that 87 of them could be a danger if they got into the environment.

Some chemicals in liquid crystal displays (LCDs) could alter genes, they said. Animal cells mutated unexpectedly if exposed, and preliminary results of their ongoing study published in Proceedings of the National Academy of Sciences on Monday showed that one of the most polluted places was the home.

Researchers said about a quarter of the chemicals from screens they tested might be pollutants. Photo: Getty alt=Researchers said about a quarter of the chemicals from screens they tested might be pollutants. Photo: Getty

Studies found that excessive radiation from screens could speed up the ageing of skin and blue light from diodes could harm the retina of the eye. "But nobody has looked beyond the brightness to unveil the dark secrets behind," Su said.

Over the years, screen panel manufacturers have pushed LCD technology to higher resolutions and faster refreshing rates, but the chemical composition of the liquid crystal that fills their screens has hardly changed.

Su and colleagues produced a list of chemicals used by manufacturers and found that 87 " about a quarter of the substances tested " might be "persisting organic pollutants" that were not only harmful to health, but their composition meant they would take years or sometimes decades to decompose. The exact effect of these chemicals was unknown.

Smartphones mean booming demand for components such as screens. Photo: Ben Sin alt=Smartphones mean booming demand for components such as screens. Photo: Ben Sin

They exposed embryonic chicken cells to liquid crystal taken from the screens and compared them to cells grown in normal conditions. They found genetic changes that suggested the exposed cells had mutated.

"Our laboratory has tested a large number of toxic substances. This [effect] is similar to the exposure of other known persistent organic pollutants," Su said.

The Nanjing team was baffled by the amount of liquid crystal in the air. They knew screens were made in dust-free factories and sealed, but their surveys of hotels, school buildings, canteens, dormitories, electronic product repair centres, homes and laboratories revealed surprising results.

Scientists say cracked screens and leaking chemicals are a worldwide problem. Photo: Shutterstock alt=Scientists say cracked screens and leaking chemicals are a worldwide problem. Photo: Shutterstock

The lowest levels were found in a canteen, a dormitory and classrooms. Su said they were not sure where the drifting liquid crystals came from. Some screens might have been cracked or broken, he said. If a screen was left on for a long time, heat and radiation might cause liquid crystal to evaporate.

There was no solution to the problem at this stage, the researchers said. To push the government for more strict regulations meant that the scientific community had to come up with more evidence and a better understanding of the problem.

"Electric device recycling plants could be a major source of emissions, with broken screens dumped everywhere and little protection. This practice must stop," he said.

This article originally appeared in the South China Morning Post (SCMP), the most authoritative voice reporting on China and Asia for more than a century. For more SCMP stories, please explore the SCMP app or visit the SCMP"s Facebook and Twitter pages. Copyright © 2019 South China Morning Post Publishers Ltd. All rights reserved.

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, digital clocks, calculators, and mobile telephones, including smartphones. LCD screens are also used on consumer electronics products such as DVD players, video game devices and clocks. LCD screens have replaced heavy, bulky cathode-ray tube (CRT) displays in nearly all applications. LCD screens are available in a wider range of screen sizes than CRT and plasma displays, with LCD screens available in sizes ranging from tiny digital watches to very large television receivers. LCDs are slowly being replaced by OLEDs, which can be easily made into different shapes, and have a lower response time, wider color gamut, virtually infinite color contrast and viewing angles, lower weight for a given display size and a slimmer profile (because OLEDs use a single glass or plastic panel whereas LCDs use two glass panels; the thickness of the panels increases with size but the increase is more noticeable on LCDs) and potentially lower power consumption (as the display is only "on" where needed and there is no backlight). OLEDs, however, are more expensive for a given display size due to the very expensive electroluminescent materials or phosphors that they use. Also due to the use of phosphors, OLEDs suffer from screen burn-in and there is currently no way to recycle OLED displays, whereas LCD panels can be recycled, although the technology required to recycle LCDs is not yet widespread. Attempts to maintain the competitiveness of LCDs are quantum dot displays, marketed as SUHD, QLED or Triluminos, which are displays with blue LED backlighting and a Quantum-dot enhancement film (QDEF) that converts part of the blue light into red and green, offering similar performance to an OLED display at a lower price, but the quantum dot layer that gives these displays their characteristics can not yet be recycled.

Since LCD screens do not use phosphors, they rarely suffer 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 are, however, susceptible to image persistence.battery-powered electronic equipment more efficiently than a CRT can be. By 2008, annual sales of televisions with LCD screens exceeded sales of CRT units worldwide, and the CRT became obsolete for most purposes.

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, along with OLED displays, 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.

The MOSFET (metal-oxide-semiconductor field-effect transistor) was invented by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959, and presented in 1960.Paul K. Weimer at RCA developed the thin-film transistor (TFT) in 1962.

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,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.

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.MicroLED.)

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),

Due to the LCD layer that generates the desired high resolution images at flashing video speeds using very low power electronics in combination with LED based backlight technologies, LCD technology has become the dominant display technology for products such as televisions, desktop monitors, notebooks, tablets, smartphones and mobile phones. Although competing OLED technology is pushed to the market, such OLED displays do not feature the HDR capabilities like LCDs in combination with 2D LED backlight technologies have, reason why the annual market of such LCD-based products is still growing faster (in volume) than OLED-based products while the efficiency of LCDs (and products like portable computers, mobile phones and televisions) may even be further improved by preventing the light to be absorbed in the colour filters of the LCD.

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,