classes of lcd monitors supplier
Liquid Crystal Display (LCD) screens are a staple in the digital display marketplace and are used in display applications across every industry. With every display application presenting a unique set of requirements, the selection of specialized LCDs has grown to meet these demands.
LCD screens can be grouped into three categories: TN (twisted nematic), IPS (in-plane switching), and VA (Vertical Alignment). Each of these screen types has its own unique qualities, almost all of them having to do with how images appear across the various screen types.
This technology consists of nematic liquid crystal sandwiched between two plates of glass. When power is applied to the electrodes, the liquid crystals twist 90°. TN (Twisted Nematic) LCDs are the most common LCD screen type. They offer full-color images, and moderate viewing angles.
TN LCDs maintain a dedicated user base despite other screen types growing in popularity due to some unique key features that TN display offer. For one,
VA, also known as Multi-Domain Vertical Alignment (MVA) dislays offer features found in both TN and IPS screens. The Pixels in VA displays align vertically to the glass substrate when voltage is applied, allowing light to pass through.
Displays with VA screens deliver wide viewing angles, high contrast, and good color reproduction. They maintain high response rates similar to TN TFTs but may not reach the same sunlight readable brightness levels as comparable TN or IPS LCDs. VA displays are generally best for applications that need to be viewed from multiple angles, like digital signage in a commercial setting.
IPS (In-Plane Switching) technology improves image quality by acting on the liquid crystal inside the display screen. When voltage is applied, the crystals rotate parallel (or “in-plane”) rather than upright to allow light to pass through. This behavior results in several significant improvements to the image quality of these screens.
IPS is superior in contrast, brightness, viewing angles, and color representation compared to TN screens. Images on screen retain their quality without becoming washed out or distorted, no matter what angle they’re viewed from. Because of this, viewers have the flexibility to view content on the screen from almost anywhere rather than having to look at the display from a front-center position.
IPS displays offer a slightly lower refresh rate than TN displays. Remember that the time for pixels to go from inactive to active is measured in milliseconds. So for most users, the difference in refresh rates will go unnoticed.
Based on current trends, IPS and TN screen types will be expected to remain the dominant formats for some time. As human interface display technology advances and new product designs are developed, customers will likely choose IPS LCDs to replace the similarly priced TN LCDs for their new projects.
Six Sigma capable, ISO 9001:2008 & ISO 14000 certified manufacturer of LCD, computer and video monitors. Features vary depending upon models and include front USB interfaces, 256 K or 16 million color displays, wall mounts, analog resistive touch-panels, serial/USB touch interfaces, on-screen display menu for brightness and contrast controls. Available with a 2-year warranty. Markets served include industrial, automotive, oil & gas, water/wastewater, semiconductors & agriculture. Modbus-IDA, OMAC & ODVA affiliated. Products are UL® listed, CSA® approved, and ATEX & CE certified. Products are RoHS compliant.
There are three main categories of panels used on modern LCD monitors; TN, VA, and IPS-type. TN panels are the most common and are typically found in budget monitors.
They offer good image quality and fast response times but suffer from poor viewing angles. VA panels are less common but offer better image quality and viewing angles than TN panels.
They once were more popular than they are, but they can still be found in some homes and businesses. They are less energy-efficient than newer monitors and can be more expensive.
There’s a good market for selling CRT monitors. They are used in a variety of settings, from businesses to schools. They offer a high-quality display and are very durable.
Because of this, they are often used in high-traffic areas. They are also relatively inexpensive, making them a good option for budget-conscious buyers.
LCD monitors are flat panel display that uses liquid crystal technology. LCD monitors are popular because they are thinner and lighter than traditional CRT monitors.
LED (Light-Emitting Diode) monitors are a new display technology that delivers bright, crisp images, vivid colors, and greater energy efficiency than standard monitors.
In addition, LED monitors use less power than traditional LCD monitors, making them more environmentally friendly. If you’re looking for a high-quality, energy-efficient monitor, an LED monitor is the way to go.
LED monitors use in-plane switching (IPS) technology, which allows for wider viewing angles and better color reproduction than traditional LCD monitors.
TN panels are the most popular LCD panels used in desktop and laptop screens. They offer good image quality and fast response times, making them ideal for gaming and other fast-paced applications.
TN panels are known for their fast response times, ideal for gaming or other activities where you must react quickly. They also tend to be more affordable than other types of panels.
In a nutshell, IPS panels are LCD panels that offer superior color reproduction and wider viewing angles. They’re often used in high-end monitors, TVs, and some smartphones and tablets.
VA panels are LCD panels that use vertically aligned crystals that tilt to allow light to pass. VA panels are less common than IPS panels for monitors, but they’re one of the most common choices for TVs.
OLED panels are the latest must-have gadget for tech-savvy consumers. These cutting-edge displays offer many advantages over traditional LCD panels, including superior image quality, higher contrast ratios, and faster response times.
There are a lot of counterfeit OLED panels on the market, so make sure you’re getting the real thing. Second, pricing is critical. OLED panels are still a relatively new technology,
VA panels typically have the highest contrast ratio, anywhere from 2500:1 up to 6000: In comparison, IPS panels usually have a lower contrast ratio of 700:1 to 1500:1, while TN monitors only have a contrast ratio of 600:1 to 1200.
LCDs have a lifespan of about 50,000 hours or 5 years. This is half the lifespan of an LED. LCDs are more susceptible to image retention and screen burn-in than LEDs.
There are three main types of connections for LCD monitors: HDMI, DisplayPort, and Mini DisplayPort. These standards are compatible with the High-Bandwidth Digital Content Protection System (HDCP).
LCD monitors only use about half the amount of electricity as CRT monitors of the same size. This is because LCD monitors have faster processor that uses less power.
The general consumer typically has very limited knowledge about the different types of LCD panels on the market and they take all of the information, specifications, and features printed on the packaging to heart. The reality is that advertisers tend to take advantage of the fact that most people conduct very minimal research before making big technological purchases—in fact, they depend on this to sell higher quantities of commercial monitors. With that in mind, how exactly do you know if you’re actually getting a good quality product that’ll suit your needs? Reading up on all of the different types of industrial LCD monitors is a good place to start!
LCD stands for liquid-crystal display. Over the years, LCD technology has become ubiquitous with various commercial and industrial screen manufacturing. LCDs are constructed of flat panels that contain liquid crystals with light modulating properties. This means that these liquid crystals use a backlight or reflector to emit light and produce either monochromatic or coloured images. LCDs are used to construct all sorts of displays from cellphones to computer screens to flat-screen TVs. Keep reading to learn everything you need to know about the different types of LCD displays on the market.
Twisted Nematic LCDs are the most commonly manufactured and used types of monitors across a wide range of industries. They’re most commonly used by gamers because they’re inexpensive and boast faster response times than most of the other display types on this list. The only real downside to these monitors is that they possess low quality and limited contrast ratios, colour reproduction, and viewing angles. However, they suffice for everyday operations.
In Plane Switching displays are considered to be among the best of the best when it comes to LCD technology as they offer superior viewing angles, excellent image quality, and vibrant colour accuracy and contrast. They’re most commonly used by graphic designers and in other applications that require the highest possible standards for image and colour reproduction.
AFFS LCDs offers far superior performance and a wider range of colour reproduction than even IPS panel technology. The applications involved in this type of LCD display are so advanced that they can minimize colour distortion without compromising on the extremely wide viewing angle. This screen is typically used in highly advanced and professional environments such as in the cockpits of commercial airplanes.
Nauticomp Inc. is the leading designer and manufacturer of high-quality LCD panels and displays. All of our touchscreen displays are made to order and customized according to your specific needs and applications. To learn more about our products, please contact us today.
Again, IPS is the clear winner here. The vertical viewing angles are very similar to the horizontal ones on both IPS and VA panels. Unfortunately, this is one area where TN panels are usually much, much worse. TN monitors degrade rapidly from below, and colors actually inverse - resulting in a negative image that can be distracting. For this reason, if you decide to buy a TN monitor, look for one with an excellent height adjustment, or consider buying a VESA mounting arm, as you should mount TN monitors at eye level. Even when mounted properly, larger TN displays can appear non-uniform at the edges.
There"s usually not much difference between VA and IPS panels in terms of gray uniformity. It"s rare for monitors to have uniformity issues, and even on monitors that perform worse than average, it"s usually not noticeable with regular content. TN monitors tend to perform a bit worse than usual, though, and the top half of the screen is almost always darker than the rest, but that"s an artifact of the bad vertical viewing angles.
Black uniformity tends to vary significantly, even between individual units of the same model, and there"s no single panel type that performs the best. It"s rare for monitors to have good black uniformity, and almost every monitor we"ve tested has some noticeable cloudiness or backlight bleed. IPS and TN panels can look slightly worse due to their low contrast ratios, as the screen can take on more of a bluish tint when displaying dark scenes. Like with contrast, black uniformity issues usually aren"t very noticeable unless you"re looking at dark content and you"re in a dark room. If you only use your monitor in a bright environment, generally speaking, you don"t need to worry about black uniformity.
Historically, TN panels used to have the worst colors, as many of them were cheaper models that only supported 6-bit colors or used techniques like dithering (FRC) to approximate 8-bit colors. Most displays today, including TN models, are at least 8 bit, and many of them are even able to approximate 10-bit colors through dithering. New technologies, like LG"s Nano IPS and Samsung"s Quantum Dot, add an extra layer to the LCD stack and have significantly improved the color gamut of modern IPS and VA displays, leaving TN a bit behind. Between them, NANO IPS is slightly better, as it tends to offer better coverage of the Adobe RGB color space. Although the difference is minor, IPS panels still have a slight edge over VA and TN displays.
Although TN panels have caught up a bit in the SDR color space, they"re far behind when it comes to HDR, so if you"re looking for a good HDR color gamut, avoid TN panels. Between VA and IPS panels, the difference isn"t as significant; however, IPS panels still have a slight edge. The best VA panels top out at around 90% coverage of the DCI P3 color space used by most current HDR content. IPS panels go as high as 98% coverage of DCI P3, rivaling even some of the best TVs on the market. Due to the very high coverage of DCI P3 on both VA and IPS, the difference isn"t that noticeable, though, as most content won"t use the entire color space anyway.
Although not necessarily as noticeable to everyone as the differences in picture quality, there can also be a difference in motion handling between IPS, VA, and TN displays. TN panels historically offered the best gaming performance, as they had the highest refresh rates and extremely fast response times. Manufacturers have found ways to drastically improve the motion handling of VA and IPS panels, though, and the difference isn"t as pronounced.
LCD panel technology has changed drastically over the last few years, and the historical expectations for response time performance don"t necessarily hold anymore. For years, TN monitors had the fastest response times by far, but that"s started to change. New high refresh-rate IPS monitors can be just as fast.
VA panels are a bit of a strange situation. They typically have slightly slower response times overall compared to similar TN or IPS models. It"s especially noticeable in near-black scenes, where they tend to be significantly slower, resulting in dark trails behind fast-moving objects in dark scenes, commonly known as black smear. Some recent VA panels, such as the Samsung Odyssey G7 LC32G75T, get around it by overdriving the pixels. It results in much better dark scene performance but a more noticeable overshoot in brighter areas.
The examples listed above aren"t perfect. The average response time metrics shown don"t necessarily show the whole picture. Monitors also usually offer a certain level of control over the pixel overdrive, so it"s possible to adjust the response time to match your usage and personal preference. Some overdrive settings deliver a sharper image but introduce overshoot and reverse ghosting artifacts, while other modes might not be as sharp but have no distracting artifacts. You can learn more about our response time testing here.
Within each of the three types of LCD we mentioned, other related panel types use the same basic idea but with slight differences. For example, two popular variants of IPS panels include ADS (technically known as ADSDS, or Advanced Super Dimension Switch) and PLS (Plane to Line Switching). It can be hard to tell these panels apart simply based on the subpixel structure, so we"ll usually group them all as IPS, and in the text, we"ll usually refer to them as IPS-like or IPS family. There are slight differences in colors, viewing angles, and contrast, but generally speaking, they"re all very similar.
There"s another display technology that"s growing in popularity: OLED. OLED, or organic light-emitting diode, is very different from the conventional LCD technology we"ve explored above. OLED panels are electro-emissive, which means each pixel emits its own light when it receives an electric signal, eliminating the need for a backlight. Since OLED panels can turn off individual pixels, they have deep, inky blacks with no blooming around bright objects. They also have excellent wide viewing angles, a near-instantaneous response time, and excellent gray uniformity.
OLED panels aren"t perfect, though. There"s a risk of permanent burn-in, especially when there are lots of static elements on screen, like the UI elements of a PC. There aren"t many OLED monitors available, either, but they"ve started to gain popularity as laptop screens and for high-end monitors, but they"re very expensive and hard to find. They"re also not very bright in some cases, especially when large bright areas are visible on screen. The technology is still maturing, and advances in OLED technology, like Samsung"s highly-anticipated QD-OLED technology, are promising.
As you can probably tell by now, no one panel type works best for everyone; it all depends on your exact usage. Although there used to be some significant differences between panel types, as technology has improved, these differences aren"t as noticeable. The two exceptions to this are viewing angles and contrast. If you"re in a dark room, a VA panel that can display deep blacks is probably the best choice. If you"re not in a dark room, you should focus on the other features of the monitor and choose based on the features that appeal to your exact usage. IPS panels are generally preferred for office use, and TN typically offers the best gaming experience, but recent advancements in VA and IPS technology are starting to change those generalizations. For the most part, the differences between each panel type are so minor now that it doesn"t need to be directly factored into your buying decision.
TFT (Thin Film Transistor) LCD (Liquid Crystal Display) dominates the world flat panel display market now. Thanks for its low cost, sharp colors, acceptable view angles, low power consumption, manufacturing friendly design, slim physical structure etc., it has driven CRT(Cathode-Ray Tube) VFD ( Vacuum Fluorescent Display) out of market, squeezed LED (Light Emitting Diode) displays only to large size display area. TFT LCD displays find wide applications in TV, computer monitors, medical, appliance, automotive, kiosk, POS terminals, low end mobile phones, marine, aerospace, industrial meters, smart homes, handheld devices, video game systems, projectors, consumer electronic products, advertisement etc. For more information about TFT displays, please visit our knowledge base.
What we are talking about TFT LCD, it is a LCD that uses TFT technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments without TFT in each pixel.
The TN type TFT LCD display is one of the oldest and lowest cost type of LCD display technology. TN TFT LCD displays have the advantages of fast response times, but its main advantages are poor color reproduction and narrow viewing angles. Colors will shift with the viewing angle. To make things worse, it has a viewing angle with gray scale inversion issue. Scientist and engineers took great effort trying to resolve the main genetic issues. Now, TN displays can look significantly better than older TN displays from decades earlier, but overall TN TFT LCD display has inferior viewing angles and poor color in comparison to other TFT LCD technologies.
IPS TFT LCD display was developed by Hitachi Ltd. in 1996 to improve on the poor viewing angle and the poor color reproduction of TN panels. Its name comes from its in-cell twist/switch difference compared with TN LCD panels.The liquid crystal molecules move parallel to the panel plane instead of perpendicular to it. This change reduces the amount of light scattering in the matrix, which gives IPS its characteristic of much improved wide viewing angles and color reproduction. But IPS TFT display has the disadvantages of lower panel transmission rate and higher production cost compared withTN type TFT displays, but these flaws can’t prevent it to be used in high end display applications which need superior color, contrast, viewing angle and crispy images.
The mono-domain VA technology is widely used for monochrome LCD displays to provide pure black background and better contrast, its uniformly alignment of the liquid crystal molecules makes the brightness changing with the viewing angle.
MVA solves this problem by causing the liquid crystal molecules to have more than one direction on a single pixel. This is done by dividing the pixel into two or four regions – called domains – and by using protrusions on the glass surfaces to pretilt the liquid crystal molecules in the different directions. In this way, the brightness of the LCD display can be made to appear uniform over a wide range of viewing angles.
This is an LCD technology derived from the IPS by Boe-Hydis of Korea. Known as fringe field switching (FFS) until 2003, advanced fringe field switching is a technology similar to IPS offering superior performance and color gamut with high luminosity. Color shift and deviation caused by light leakage is corrected by optimizing the white gamut, which also enhances white/grey reproduction. AFFS is developed by Hydis Technologies Co., Ltd, Korea (formally Hyundai Electronics, LCD Task Force).
The AFFS is similar to the IPS in concept; both align the crystal molecules in a parallel-to-substrate manner, improving viewing angles. However, the AFFS is more advanced and can better optimize power consumption. Most notably, AFFS has high transmittance, meaning that less of the light energy is absorbed within the liquid crystal layer and more is transmitted towards the surface. IPS TFT LCDs typically have lower transmittances, hence the need for the brighter backlight. This transmittance difference is rooted in the AFFS’s compact, maximized active cell space beneath each pixel.
The most basic LCD introduced above is called passive matrix LCDs which can be found mostly in low end or simple applications like, calculators, utility meters, early time digital watches, alarm clocks etc. Passive matrix LCDs have a lot of limitations, like the narrow viewing angle, slow response speed, dim, but it is great for power consumption.
In order to improve upon the drawbacks, scientists and engineers developed active matrix LCD technology. The most widely used is TFT (Thin Film Transistor) LCD technology. Based on TFT LCD, even more modern LCD technologies are developed. The best known is IPS (In Plane Switching) LCD. It has super wide viewing angle, superior image picture quality, fast response, great contrast, less burn-in defects etc.
IPS LCDs are widely used in LCD monitors, LCD TVs, Iphone, pads etc. Samsung even revolutionized the LED backlighting to be QLED (quantum dot) to switch off LEDs wherever light is not needed to produce deeper blacks.
– Twisted Nematic Display: The TN (Twisted Nematic) LCDs production can be done most frequently and used different kinds of displays all over the industries. These displays are most frequently used by gamers as they are cheap & have quick response time as compared with other displays. The main disadvantage of these displays is that they have low quality as well as partial contrast ratios, viewing angles & reproduction of color. But, these devices are sufficient for daily operations.
– In-Plane Switching Display:IPS displays are considered to be the best LCD because they provide good image quality, higher viewing angles, vibrant color precision & difference. These displays are mostly used by graphic designers & in some other applications, LCDs need the maximum potential standards for the reproduction of image & color.
– The structure of this panel generates deeper blacks as well as better colors as compared with the twisted nematic display. And several crystal alignments can permit for better viewing angles as compared with TN type displays. These displays arrive with a tradeoff because they are expensive as compared with other displays. And also they have slow response times & low refresh rates.
– Advanced Fringe Field Switching (AFFS): AFFS LCDs offer the best performance & a wide range of color reproduction as compared with IPS displays. The applications of AFFS are very advanced because they can reduce the distortion of color without compromising on the broad viewing angle. Usually, this display is used in highly advanced as well as professional surroundings like in the viable airplane cockpits.
– Passive and Active Matrix Displays: The Passive-matrix type LCDs works with a simple grid so that charge can be supplied to a specific pixel on the LCD. One glass layer gives columns whereas the other one gives rows that are designed by using a clear conductive material like indium-tin-oxide. The passive-matrix system has major drawbacks particularly response time is slow & inaccurate voltage control. The response time of the display mainly refers to the capability of the display to refresh the displayed image.
– Active-matrix type LCDs mainly depend on TFT (thin-film transistors). These transistors are small switching transistors as well as capacitors which are placed within a matrix over a glass substrate. When the proper row is activated then a charge can be transmitted down the exact column so that a specific pixel can be addressed, because all of the additional rows that the column intersects are switched OFF, simply the capacitor next to the designated pixel gets a charge.
LCD technologies have great advantages of light, thin, low power consumption which made wall TVs, laptops, smartphones, pad possible. On its way to progress, it wiped out the competition of many display technologies. We don’t see CRT monitors on our desks and plasma displays TV at our home anymore. LCD Technologies dominant the display market now. But any technology has the limitations.
LCD technologies have slow response times especially at low temperature, limited viewing angles, backlighting is needed. Focus on LCD drawbacks, OLED (Organic Light Emitting Diodes) technology was developed. Some high-end TV and mobile phones start to use AMOLED (Active Matrix Organic Light Emitting Diodes) displays.
This cutting-edge technology provides even better color reproduction, clear image quality, better color gamut, less power consumption when compared to LCD technology. Please note, OLED displays include AMOLED and PMOLED (Passive Matrix Organic Light Emitting Diodes). What you need to choose is AMOLED for your TV and mobile phones instead of PMOLED.
Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is switched ON. Vertical ridges etched on the surface are smooth.
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directlybacklight or reflector to produce images in color or monochrome.seven-segment displays, as in a digital clock, are all good examples of devices with these displays. They use the same basic technology, except that arbitrary images are made from a matrix of small pixels, while other displays have larger elements. LCDs can either be normally on (positive) or off (negative), depending on the polarizer arrangement. For example, a character positive LCD with a backlight will have black lettering on a background that is the color of the backlight, and a character negative LCD will have a black background with the letters being of the same color as the backlight. Optical filters are added to white on blue LCDs to give them their characteristic appearance.
LCDs are used in a wide range of applications, including LCD televisions, computer monitors, instrument panels, aircraft cockpit displays, and indoor and outdoor signage. Small LCD screens are common in LCD projectors and portable consumer devices such as digital cameras, watches, calculators, and mobile telephones, including smartphones. LCD screens have replaced heavy, bulky and less energy-efficient cathode-ray tube (CRT) displays in nearly all applications. The phosphors used in CRTs make them vulnerable to image burn-in when a static image is displayed on a screen for a long time, e.g., the table frame for an airline flight schedule on an indoor sign. LCDs do not have this weakness, but are still susceptible to image persistence.
Each pixel of an LCD typically consists of a layer of molecules aligned between two transparent electrodes, often made of Indium-Tin oxide (ITO) and two polarizing filters (parallel and perpendicular polarizers), the axes of transmission of which are (in most of the cases) perpendicular to each other. Without the liquid crystal between the polarizing filters, light passing through the first filter would be blocked by the second (crossed) polarizer. Before an electric field is applied, the orientation of the liquid-crystal molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic (TN) device, the surface alignment directions at the two electrodes are perpendicular to each other, and so the molecules arrange themselves in a helical structure, or twist. This induces the rotation of the polarization of the incident light, and the device appears gray. If the applied voltage is large enough, the liquid crystal molecules in the center of the layer are almost completely untwisted and the polarization of the incident light is not rotated as it passes through the liquid crystal layer. This light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts thus constituting different levels of gray.
The chemical formula of the liquid crystals used in LCDs may vary. Formulas may be patented.Sharp Corporation. The patent that covered that specific mixture expired.
Most color LCD systems use the same technique, with color filters used to generate red, green, and blue subpixels. The LCD color filters are made with a photolithography process on large glass sheets that are later glued with other glass sheets containing a TFT array, spacers and liquid crystal, creating several color LCDs that are then cut from one another and laminated with polarizer sheets. Red, green, blue and black photoresists (resists) are used. All resists contain a finely ground powdered pigment, with particles being just 40 nanometers across. The black resist is the first to be applied; this will create a black grid (known in the industry as a black matrix) that will separate red, green and blue subpixels from one another, increasing contrast ratios and preventing light from leaking from one subpixel onto other surrounding subpixels.Super-twisted nematic LCD, where the variable twist between tighter-spaced plates causes a varying double refraction birefringence, thus changing the hue.
LCD in a Texas Instruments calculator with top polarizer removed from device and placed on top, such that the top and bottom polarizers are perpendicular. As a result, the colors are inverted.
The optical effect of a TN device in the voltage-on state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, TN displays with low information content and no backlighting are usually operated between crossed polarizers such that they appear bright with no voltage (the eye is much more sensitive to variations in the dark state than the bright state). As most of 2010-era LCDs are used in television sets, monitors and smartphones, they have high-resolution matrix arrays of pixels to display arbitrary images using backlighting with a dark background. When no image is displayed, different arrangements are used. For this purpose, TN LCDs are operated between parallel polarizers, whereas IPS LCDs feature crossed polarizers. In many applications IPS LCDs have replaced TN LCDs, particularly in smartphones. Both the liquid crystal material and the alignment layer material contain ionic compounds. If an electric field of one particular polarity is applied for a long period of time, this ionic material is attracted to the surfaces and degrades the device performance. This is avoided either by applying an alternating current or by reversing the polarity of the electric field as the device is addressed (the response of the liquid crystal layer is identical, regardless of the polarity of the applied field).
Displays for a small number of individual digits or fixed symbols (as in digital watches and pocket calculators) can be implemented with independent electrodes for each segment.alphanumeric or variable graphics displays are usually implemented with pixels arranged as a matrix consisting of electrically connected rows on one side of the LC layer and columns on the other side, which makes it possible to address each pixel at the intersections. The general method of matrix addressing consists of sequentially addressing one side of the matrix, for example by selecting the rows one-by-one and applying the picture information on the other side at the columns row-by-row. For details on the various matrix addressing schemes see passive-matrix and active-matrix addressed LCDs.
LCDs are manufactured in cleanrooms borrowing techniques from semiconductor manufacturing and using large sheets of glass whose size has increased over time. Several displays are manufactured at the same time, and then cut from the sheet of glass, also known as the mother glass or LCD glass substrate. The increase in size allows more displays or larger displays to be made, just like with increasing wafer sizes in semiconductor manufacturing. The glass sizes are as follows:
Until Gen 8, manufacturers would not agree on a single mother glass size and as a result, different manufacturers would use slightly different glass sizes for the same generation. Some manufacturers have adopted Gen 8.6 mother glass sheets which are only slightly larger than Gen 8.5, allowing for more 50 and 58 inch LCDs to be made per mother glass, specially 58 inch LCDs, in which case 6 can be produced on a Gen 8.6 mother glass vs only 3 on a Gen 8.5 mother glass, significantly reducing waste.AGC Inc., Corning Inc., and Nippon Electric Glass.
The origins and the complex history of liquid-crystal displays from the perspective of an insider during the early days were described by Joseph A. Castellano in Liquid Gold: The Story of Liquid Crystal Displays and the Creation of an Industry.IEEE History Center.Peter J. Wild, can be found at the Engineering and Technology History Wiki.
In 1888,Friedrich Reinitzer (1858–1927) discovered the liquid crystalline nature of cholesterol extracted from carrots (that is, two melting points and generation of colors) and published his findings at a meeting of the Vienna Chemical Society on May 3, 1888 (F. Reinitzer: Beiträge zur Kenntniss des Cholesterins, Monatshefte für Chemie (Wien) 9, 421–441 (1888)).Otto Lehmann published his work "Flüssige Kristalle" (Liquid Crystals). In 1911, Charles Mauguin first experimented with liquid crystals confined between plates in thin layers.
In 1922, Georges Friedel described the structure and properties of liquid crystals and classified them in three types (nematics, smectics and cholesterics). In 1927, Vsevolod Frederiks devised the electrically switched light valve, called the Fréedericksz transition, the essential effect of all LCD technology. In 1936, the Marconi Wireless Telegraph company patented the first practical application of the technology, "The Liquid Crystal Light Valve". In 1962, the first major English language publication Molecular Structure and Properties of Liquid Crystals was published by Dr. George W. Gray.RCA found that liquid crystals had some interesting electro-optic characteristics and he realized an electro-optical effect by generating stripe-patterns in a thin layer of liquid crystal material by the application of a voltage. This effect is based on an electro-hydrodynamic instability forming what are now called "Williams domains" inside the liquid crystal.
In 1964, George H. Heilmeier, then working at the RCA laboratories on the effect discovered by Williams achieved the switching of colors by field-induced realignment of dichroic dyes in a homeotropically oriented liquid crystal. Practical problems with this new electro-optical effect made Heilmeier continue to work on scattering effects in liquid crystals and finally the achievement of the first operational liquid-crystal display based on what he called the George H. Heilmeier was inducted in the National Inventors Hall of FameIEEE Milestone.
In the late 1960s, pioneering work on liquid crystals was undertaken by the UK"s Royal Radar Establishment at Malvern, England. The team at RRE supported ongoing work by George William Gray and his team at the University of Hull who ultimately discovered the cyanobiphenyl liquid crystals, which had correct stability and temperature properties for application in LCDs.
The idea of a TFT-based liquid-crystal display (LCD) was conceived by Bernard Lechner of RCA Laboratories in 1968.dynamic scattering mode (DSM) LCD that used standard discrete MOSFETs.
On December 4, 1970, the twisted nematic field effect (TN) in liquid crystals was filed for patent by Hoffmann-LaRoche in Switzerland, (Swiss patent No. 532 261) with Wolfgang Helfrich and Martin Schadt (then working for the Central Research Laboratories) listed as inventors.Brown, Boveri & Cie, its joint venture partner at that time, which produced TN displays for wristwatches and other applications during the 1970s for the international markets including the Japanese electronics industry, which soon produced the first digital quartz wristwatches with TN-LCDs and numerous other products. James Fergason, while working with Sardari Arora and Alfred Saupe at Kent State University Liquid Crystal Institute, filed an identical patent in the United States on April 22, 1971.ILIXCO (now LXD Incorporated), produced LCDs based on the TN-effect, which soon superseded the poor-quality DSM types due to improvements of lower operating voltages and lower power consumption. Tetsuro Hama and Izuhiko Nishimura of Seiko received a US patent dated February 1971, for an electronic wristwatch incorporating a TN-LCD.
In 1972, the concept of the active-matrix thin-film transistor (TFT) liquid-crystal display panel was prototyped in the United States by T. Peter Brody"s team at Westinghouse, in Pittsburgh, Pennsylvania.Westinghouse Research Laboratories demonstrated the first thin-film-transistor liquid-crystal display (TFT LCD).high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays.active-matrix liquid-crystal display (AM LCD) in 1974, and then Brody coined the term "active matrix" in 1975.
In 1972 North American Rockwell Microelectronics Corp introduced the use of DSM LCDs for calculators for marketing by Lloyds Electronics Inc, though these required an internal light source for illumination.Sharp Corporation followed with DSM LCDs for pocket-sized calculators in 1973Seiko and its first 6-digit TN-LCD quartz wristwatch, and Casio"s "Casiotron". Color LCDs based on Guest-Host interaction were invented by a team at RCA in 1968.TFT LCDs similar to the prototypes developed by a Westinghouse team in 1972 were patented in 1976 by a team at Sharp consisting of Fumiaki Funada, Masataka Matsuura, and Tomio Wada,
In 1983, researchers at Brown, Boveri & Cie (BBC) Research Center, Switzerland, invented the passive matrix-addressed LCDs. H. Amstutz et al. were listed as inventors in the corresponding patent applications filed in Switzerland on July 7, 1983, and October 28, 1983. Patents were granted in Switzerland CH 665491, Europe EP 0131216,
The first color LCD televisions were developed as handheld televisions in Japan. In 1980, Hattori Seiko"s R&D group began development on color LCD pocket televisions.Seiko Epson released the first LCD television, the Epson TV Watch, a wristwatch equipped with a small active-matrix LCD television.dot matrix TN-LCD in 1983.Citizen Watch,TFT LCD.computer monitors and LCD televisions.3LCD projection technology in the 1980s, and licensed it for use in projectors in 1988.compact, full-color LCD projector.
In 1990, under different titles, inventors conceived electro optical effects as alternatives to twisted nematic field effect LCDs (TN- and STN- LCDs). One approach was to use interdigital electrodes on one glass substrate only to produce an electric field essentially parallel to the glass substrates.Germany by Guenter Baur et al. and patented in various countries.Hitachi work out various practical details of the IPS technology to interconnect the thin-film transistor array as a matrix and to avoid undesirable stray fields in between pixels.
Hitachi also improved the viewing angle dependence further by optimizing the shape of the electrodes (Super IPS). NEC and Hitachi become early manufacturers of active-matrix addressed LCDs based on the IPS technology. This is a milestone for implementing large-screen LCDs having acceptable visual performance for flat-panel computer monitors and television screens. In 1996, Samsung developed the optical patterning technique that enables multi-domain LCD. Multi-domain and In Plane Switching subsequently remain the dominant LCD designs through 2006.South Korea and Taiwan,
In 2007 the image quality of LCD televisions surpassed the image quality of cathode-ray-tube-based (CRT) TVs.LCD TVs were projected to account 50% of the 200 million TVs to be shipped globally in 2006, according to Displaybank.Toshiba announced 2560 × 1600 pixels on a 6.1-inch (155 mm) LCD panel, suitable for use in a tablet computer,
In 2016, Panasonic developed IPS LCDs with a contrast ratio of 1,000,000:1, rivaling OLEDs. This technology was later put into mass production as dual layer, dual panel or LMCL (Light Modulating Cell Layer) LCDs. The technology uses 2 liquid crystal layers instead of one, and may be used along with a mini-LED backlight and quantum dot sheets.
Since LCDs produce no light of their own, they require external light to produce a visible image.backlight. Active-matrix LCDs are almost always backlit.Transflective LCDs combine the features of a backlit transmissive display and a reflective display.
CCFL: The LCD panel is lit either by two cold cathode fluorescent lamps placed at opposite edges of the display or an array of parallel CCFLs behind larger displays. A diffuser (made of PMMA acrylic plastic, also known as a wave or light guide/guiding plateinverter to convert whatever DC voltage the device uses (usually 5 or 12 V) to ≈1000 V needed to light a CCFL.
EL-WLED: The LCD panel is lit by a row of white LEDs placed at one or more edges of the screen. A light diffuser (light guide plate, LGP) is then used to spread the light evenly across the whole display, similarly to edge-lit CCFL LCD backlights. The diffuser is made out of either PMMA plastic or special glass, PMMA is used in most cases because it is rugged, while special glass is used when the thickness of the LCD is of primary concern, because it doesn"t expand as much when heated or exposed to moisture, which allows LCDs to be just 5mm thick. Quantum dots may be placed on top of the diffuser as a quantum dot enhancement film (QDEF, in which case they need a layer to be protected from heat and humidity) or on the color filter of the LCD, replacing the resists that are normally used.
WLED array: The LCD panel is lit by a full array of white LEDs placed behind a diffuser behind the panel. LCDs that use this implementation will usually have the ability to dim or completely turn off the LEDs in the dark areas of the image being displayed, effectively increasing the contrast ratio of the display. The precision with which this can be done will depend on the number of dimming zones of the display. The more dimming zones, the more precise the dimming, with less obvious blooming artifacts which are visible as dark grey patches surrounded by the unlit areas of the LCD. As of 2012, this design gets most of its use from upscale, larger-screen LCD televisions.
RGB-LED array: Similar to the WLED array, except the panel is lit by a full array of RGB LEDs. While displays lit with white LEDs usually have a poorer color gamut than CCFL lit displays, panels lit with RGB LEDs have very wide color gamuts. This implementation is most popular on professional graphics editing LCDs. As of 2012, LCDs in this category usually cost more than $1000. As of 2016 the cost of this category has drastically reduced and such LCD televisions obtained same price levels as the former 28" (71 cm) CRT based categories.
Monochrome LEDs: such as red, green, yellow or blue LEDs are used in the small passive monochrome LCDs typically used in clocks, watches and small appliances.
Mini-LED: Backlighting with Mini-LEDs can support over a thousand of Full-area Local Area Dimming (FLAD) zones. This allows deeper blacks and higher contrast ratio.
Today, most LCD screens are being designed with an LED backlight instead of the traditional CCFL backlight, while that backlight is dynamically controlled with the video information (dynamic backlight control). The combination with the dynamic backlight control, invented by Philips researchers Douglas Stanton, Martinus Stroomer and Adrianus de Vaan, simultaneously increases the dynamic range of the display system (also marketed as HDR, high dynamic range television or FLAD, full-area local area dimming).
The LCD backlight systems are made highly efficient by applying optical films such as prismatic structure (prism sheet) to gain the light into the desired viewer directions and reflective polarizing films that recycle the polarized light that was formerly absorbed by the first polarizer of the LCD (invented by Philips researchers Adrianus de Vaan and Paulus Schaareman),
A pink elastomeric connector mating an LCD panel to circuit board traces, shown next to a centimeter-scale ruler. The conductive and insulating layers in the black stripe are very small.
A standard television receiver screen, a modern LCD panel, has over six million pixels, and they are all individually powered by a wire network embedded in the screen. The fine wires, or pathways, form a grid with vertical wires across the whole screen on one side of the screen and horizontal wires across the whole screen on the other side of the screen. To this grid each pixel has a positive connection on one side and a negative connection on the other side. So the total amount of wires needed for a 1080p display is 3 x 1920 going vertically and 1080 going horizontally for a total of 6840 wires horizontally and vertically. That"s three for red, green and blue and 1920 columns of pixels for each color for a total of 5760 wires going vertically and 1080 rows of wires going horizontally. For a panel that is 28.8 inches (73 centimeters) wide, that means a wire density of 200 wires per inch along the horizontal edge.
The LCD panel is powered by LCD drivers that are carefully matched up with the edge of the LCD panel at the factory level. The drivers may be installed using several methods, the most common of which are COG (Chip-On-Glass) and TAB (Tape-automated bonding) These same principles apply also for smartphone screens that are much smaller than TV screens.anisotropic conductive film or, for lower densities, elastomeric connectors.
Monochrome and later color passive-matrix LCDs were standard in most early laptops (although a few used plasma displaysGame Boyactive-matrix became standard on all laptops. The commercially unsuccessful Macintosh Portable (released in 1989) was one of the first to use an active-matrix display (though still monochrome). Passive-matrix LCDs are still used in the 2010s for applications less demanding than laptop computers and TVs, such as inexpensive calculators. In particular, these are used on portable devices where less information content needs to be displayed, lowest power consumption (no backlight) and low cost are desired or readability in direct sunlight is needed.
A comparison between a blank passive-matrix display (top) and a blank active-matrix display (bottom). A passive-matrix display can be identified when the blank background is more grey in appearance than the crisper active-matrix display, fog appears on all edges of the screen, and while pictures appear to be fading on the screen.
Displays having a passive-matrix structure are employing Crosstalk between activated and non-activated pixels has to be handled properly by keeping the RMS voltage of non-activated pixels below the threshold voltage as discovered by Peter J. Wild in 1972,
STN LCDs have to be continuously refreshed by alternating pulsed voltages of one polarity during one frame and pulses of opposite polarity during the next frame. Individual pixels are addressed by the corresponding row and column circuits. This type of display is called response times and poor contrast are typical of passive-matrix addressed LCDs with too many pixels and driven according to the "Alt & Pleshko" drive scheme. Welzen and de Vaan also invented a non RMS drive scheme enabling to drive STN displays with video rates and enabling to show smooth moving video images on an STN display.
Bistable LCDs do not require continuous refreshing. Rewriting is only required for picture information changes. In 1984 HA van Sprang and AJSM de Vaan invented an STN type display that could be operated in a bistable mode, enabling extremely high resolution images up to 4000 lines or more using only low voltages.
High-resolution color displays, such as modern LCD computer monitors and televisions, use an active-matrix structure. A matrix of thin-film transistors (TFTs) is added to the electrodes in contact with the LC layer. Each pixel has its own dedicated transistor, allowing each column line to access one pixel. When a row line is selected, all of the column lines are connected to a row of pixels and voltages corresponding to the picture information are driven onto all of the column lines. The row line is then deactivated and the next row line is selected. All of the row lines are selected in sequence during a refresh operation. Active-matrix addressed displays look brighter and sharper than passive-matrix addressed displays of the same size, and generally have quicker response times, producing much better images. Sharp produces bistable reflective LCDs with a 1-bit SRAM cell per pixel that only requires small amounts of power to maintain an image.
Segment LCDs can also have color by using Field Sequential Color (FSC LCD). This kind of displays have a high speed passive segment LCD panel with an RGB backlight. The backlight quickly changes color, making it appear white to the naked eye. The LCD panel is synchronized with the backlight. For example, to make a segment appear red, the segment is only turned ON when the backlight is red, and to make a segment appear magenta, the segment is turned ON when the backlight is blue, and it continues to be ON while the backlight becomes red, and it turns OFF when the backlight becomes green. To make a segment appear black, the segment is always turned ON. An FSC LCD divides a color image into 3 images (one Red, one Green and one Blue) and it displays them in order. Due to persistence of vision, the 3 monochromatic images appear as one color image. An FSC LCD needs an LCD panel with a refresh rate of 180 Hz, and the response time is reduced to just 5 milliseconds when compared with normal STN LCD panels which have a response time of 16 milliseconds.
Samsung introduced UFB (Ultra Fine & Bright) displays back in 2002, utilized the super-birefringent effect. It has the luminance, color gamut, and most of the contrast of a TFT-LCD, but only consumes as much power as an STN display, according to Samsung. It was being used in a variety of Samsung cellular-telephone models produced until late 2006, when Samsung stopped producing UFB displays. UFB displays were also used in certain models of LG mobile phones.
Twisted nematic displays contain liquid crystals that twist and untwist at varying degrees to allow light to pass through. When no voltage is applied to a TN liquid crystal cell, polarized light passes through the 90-degrees twisted LC layer. In proportion to the voltage applied, the liquid crystals untwist changing the polarization and blocking the light"s path. By properly adjusting the level of the voltage almost any gray level or transmission can be achieved.
In-plane switching is an LCD technology that aligns the liquid crystals in a plane parallel to the glass substrates. In this method, the electrical field is applied through opposite electrodes on the same glass substrate, so that the liquid crystals can be reoriented (switched) essentially in the same plane, although fringe fields inhibit a homogeneous reorientation. This requires two transistors for each pixel instead of the single transistor needed for a standard thin-film transistor (TFT) display. The IPS technology is used in everything from televisions, computer monitors, and even wearable devices, especially almost all LCD smartphone panels are IPS/FFS mode. IPS displays belong to the LCD panel family screen types. The other two types are VA and TN. Before LG Enhanced IPS was introduced in 2001 by Hitachi as 17" monitor in Market, the additional transistors resulted in blocking more transmission area, thus requiring a brighter backlight and consuming more power, making this type of display less desirable for notebook computers. Panasonic Himeji G8.5 was using an enhanced version of IPS, also LGD in Korea, then currently the world biggest LCD panel manufacture BOE in China is also IPS/FFS mode TV panel.
In 2015 LG Display announced the implementation of a new technology called M+ which is the addition of white subpixel along with the regular RGB dots in their IPS panel technology.
Most of the new M+ technology was employed on 4K TV sets which led to a controversy after tests showed that the addition of a white sub pixel replacing the traditional RGB structure would reduce the resolution by around 25%. This means that a 4K TV cannot display the full UHD TV standard. The media and internet users later called this "RGBW" TVs because of the white sub pixel. Although LG Display has developed this technology for use in notebook display, outdoor and smartphones, it became more popular in the TV market because the announced 4K UHD resolution but still being incapable of achieving true UHD resolution defined by the CTA as 3840x2160 active pixels with 8-bit color. This negatively impacts the rendering of text, making it a bit fuzzier, which is especially noticeable when a TV is used as a PC monitor.
In 2011, LG claimed the smartphone LG Optimus Black (IPS LCD (LCD NOVA)) has the brightness up to 700 nits, while the competitor has only IPS LCD with 518 nits and double an active-matrix OLED (AMOLED) display with 305 nits. LG also claimed the NOVA display to be 50 percent more efficient than regular LCDs and to consume only 50 percent of the power of AMOLED displays when producing white on screen.
This pixel-layout is found in S-IPS LCDs. A chevron shape is used to widen the viewing cone (range of viewing directions with good contrast and low color shift).
Vertical-alignment displays are a form of LCDs in which the liquid crystals naturally align vertically to the glass substrates. When no voltage is applied, the liquid crystals remain perpendicular to the substrate, creating a black display between crossed polarizers. When voltage is applied, the liquid crystals shift to a tilted position, allowing light to pass through and create a gray-scale display depending on the amount of tilt generated by the electric field. It has a deeper-black background, a higher contrast ratio, a wider viewing angle, and better image quality at extreme temperatures than traditional twisted-nematic displays.
Blue phase mode LCDs have been shown as engineering samples early in 2008, but they are not in mass-production. The physics of blue phase mode LCDs suggest that very short switching times (≈1 ms) can be achieved, so time sequential color control can possibly be realized and expensive color filters would be obsolete.
Some LCD panels have defective transistors, causing permanently lit or unlit pixels which are commonly referred to as stuck pixels or dead pixels respectively. Unlike integrated circuits (ICs), LCD panels with a few defective transistors are usually still usable. Manufacturers" policies for the acceptable number of defective pixels vary greatly. At one point, Samsung held a zero-tolerance policy for LCD monitors sold in Korea.ISO 13406-2 standard.
Dead pixel policies are often hotly debated between manufacturers and customers. To regulate the acceptability of defects and to protect the end user, ISO released the ISO 13406-2 standard,ISO 9241, specifically ISO-9241-302, 303, 305, 307:2008 pixel defects. However, not every LCD manufacturer conforms to the ISO standard and the ISO standard is quite often interpreted in different ways. LCD panels are more likely to have defects than most ICs due to their larger size. For example, a 300 mm SVGA LCD has 8 defects and a 150 mm wafer has only 3 defects. However, 134 of the 137 dies on the wafer will be acceptable, whereas rejection of the whole LCD panel would be a 0% yield. In recent years, quality control has been improved. An SVGA LCD panel with 4 defective pixels is usually considered defective and customers can request an exchange for a new one.
Some manufacturers, notably in South Korea where some of the largest LCD panel manufacturers, such as LG, are located, now have a zero-defective-pixel guarantee, which is an extra screening process which can then determine "A"- and "B"-grade panels.clouding (or less commonly mura), which describes the uneven patches of changes in luminance. It is most visible in dark or black areas of displayed scenes.
The zenithal bistable device (ZBD), developed by Qinetiq (formerly DERA), can retain an image without power. The crystals may exist in one of two stable orientations ("black" and "white") and power is only required to change the image. ZBD Displays is a spin-off company from QinetiQ who manufactured both grayscale and color ZBD devices. Kent Displays has also developed a "no-power" display that uses polymer stabilized cholesteric liquid crystal (ChLCD). In 2009 Kent demonstrated the use of a ChLCD to cover the entire surface of a mobile phone, allowing it to change colors, and keep that color even when power is removed.
In 2004, researchers at the University of Oxford demonstrated two new types of zero-power bistable LCDs based on Zenithal bistable techniques.e.g., BiNem technology, are based mainly on the surface properties and need specific weak anchoring materials.
Resolution The resolution of an LCD is expressed by the number of columns and rows of pixels (e.g., 1024×768). Each pixel is usually composed 3 sub-pixels, a red, a green, and a blue one. This had been one of the few features of LCD performance that remained uniform among different designs. However, there are newer designs that share sub-pixels among pixels and add Quattron which attempt to efficiently increase the perceived resolution of a display without increasing the actual resolution, to mixed results.
Spatial performance: For a computer monitor or some other display that is being viewed from a very close distance, resolution is often expressed in terms of dot pitch or pixels per inch, which is consistent with the printing industry. Display density varies per application, with televisions generally having a low density for long-distance viewing and portable devices having a high density for close-range detail. The Viewing Angle of an LCD may be important depending on the display and its usage, the limitations of certain display technologies mean the display only displays accurately at certain angles.
Temporal performance: the temporal resolution of an LCD is how well it can display changing images, or the accuracy and the number of times per second the display draws the data it is being given. LCD pixels do not flash on/off between frames, so LCD monitors exhibit no refresh-induced flicker no matter how low the refresh rate.
Color performance: There are multiple terms to describe different aspects of color performance of a display. Color gamut is the range of colors that can be displayed, and color depth, which is the fineness with which the color range is divided. Color gamut is a relatively straight forward feature, but it is rarely discussed in marketing materials except at the professional level. Having a color range that exceeds the content being shown on the screen has no benefits, so displays are only made to perform within or below the range of a certain specification.white point and gamma correction, which describe what color white is and how the other colors are displayed relative to white.
Brightness and contrast ratio: Contrast ratio is the ratio of the brightness of a full-on pixel to a full-off pixel. The LCD itself is only a light valve and does not generate light; the light comes from a backlight that is either fluorescent or a set of LEDs. Brightness is usually stated as the maximum light output of the LCD, which can vary greatly based on the transparency of the LCD and the brightness of the backlight. Brighter backlight allows stronger contrast and higher dynamic range (HDR displays are graded in peak luminance), but there is always a trade-off between brightness and power consumption.
Low power consumption. Depending on the set display brightness and content being displayed, the older CCFT backlit models typically use less than half of the power a CRT monitor of the same size viewing area would use, and the modern LED backlit models typically use 10–25% of the power a CRT monitor would use.
Usually no refresh-rate flicker, because the LCD pixels hold their state between refreshes (which are usually done at 200 Hz or faster, regardless of the input refresh rate).
No theoretical resolution limit. When multiple LCD panels are used together to create a single canvas, each additional panel increases the total resolution of the display, which is commonly called stacked resolution.
LCDs can be made transparent and flexible, but they cannot emit light without a backlight like OLED and microLED, which are other technologies that can also be made flexible and transparent.
As an inherently digital device, the LCD can natively display digital data from a DVI or HDMI connection without requiring conversion to analog. Some LCD panels have native fiber optic inputs in addition to DVI and HDMI.
Limited viewing angle in some older or cheaper monitors, causing color, saturation, contrast and brightness to vary with user position, even within the intended viewing angle. Special films can be used to increase the viewing angles of LCDs.
Uneven backlighting in some monitors (more common in IPS-types and older TNs), causing brightness distortion, especially toward the edges ("backlight bleed").
As of 2012, mos