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117-413: 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 to display information. Liquid crystals do not emit light directly but instead use a backlight or reflector to produce images in color or monochrome . LCDs are available to display arbitrary images (as in

234-453: 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

351-734: A silicon nitride gate dielectric layer. The a-Si TFT was soon recognized as being more suitable for a large-area AM LCD. This led to commercial research and development (R&D) of AM LCD panels based on a-Si TFTs in Japan. By 1982, pocket TVs based on AM LCD technology were developed in Japan. In 1982, Fujitsu 's S. Kawai fabricated an a-Si dot-matrix display , and Canon 's Y. Okubo fabricated a-Si twisted nematic (TN) and guest-host LCD panels. In 1983, Toshiba 's K. Suzuki produced a-Si TFT arrays compatible with CMOS (complementary metal–oxide–semiconductor) integrated circuits (ICs), Canon's M. Sugata fabricated an a-Si color LCD panel, and

468-405: A silicon-on-insulator (SOI), at a relatively low temperature of 200   °C. A Hosiden research team led by T. Sunata in 1986 used a-Si TFTs to develop a 7-inch color AM LCD panel, and a 9-inch AM LCD panel. In the late 1980s, Hosiden supplied monochrome TFT LCD panels to Apple Computer . In 1988, a Sharp research team led by engineer T. Nagayasu used hydrogenated a-Si TFTs to demonstrate

585-460: A wall socket ) or a battery to maintain an image on the display or change the image. This refresh typically occurs many times a second. If this is not done, for example, if there is a power outage , the pixels will gradually lose their coherent state, and the image will "fade" from the screen. The following flat-display technologies have been commercialized in 1990s to 2010s: Technologies that were extensively researched, but their commercialization

702-630: A 14-inch full-color LCD display, which convinced the electronics industry that LCD would eventually replace cathode-ray tube (CRT) as the standard television display technology . The same year, Sharp launched TFT LCD panels for notebook PCs . In 1992, Toshiba and IBM Japan introduced a 12.1-inch color SVGA panel for the first commercial color laptop by IBM . TFTs can also be made out of indium gallium zinc oxide ( IGZO ). TFT-LCDs with IGZO transistors first showed up in 2012, and were first manufactured by Sharp Corporation. IGZO allows for higher refresh rates and lower power consumption. In 2021,

819-623: A 14-inch, active-matrix, full-color, full-motion TFT-LCD. This led to Japan launching an LCD industry, which developed large-size LCDs, including TFT computer monitors and LCD televisions. Epson developed the 3LCD projection technology in the 1980s, and licensed it for use in projectors in 1988. Epson's VPJ-700, released in January 1989, was the world's first 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

936-457: A CdSe (cadmium selenide) TFT, which they used to demonstrate the first CdSe thin-film-transistor liquid-crystal display (TFT LCD). The Westinghouse group also reported on operational TFT electroluminescence (EL) in 1973, using CdSe. Brody and Fang-Chen Luo demonstrated the first flat active-matrix liquid-crystal display (AM LCD) using CdSe in 1974, and then Brody coined the term "active matrix" in 1975. However, mass production of this device

1053-492: A Gen 8.5 mother glass, significantly reducing waste. The thickness of the mother glass also increases with each generation, so larger mother glass sizes are better suited for larger displays. An LCD module (LCM) is a ready-to-use LCD with a backlight. Thus, a factory that makes LCD modules does not necessarily make LCDs, it may only assemble them into the modules. LCD glass substrates are made by companies such as AGC Inc. , Corning Inc. , and Nippon Electric Glass . The origin and

1170-430: A TFT-based liquid-crystal display (LCD) was conceived by Bernard J. Lechner of RCA Laboratories in 1968. Lechner, F.J. Marlowe, E.O. Nester and J. Tults demonstrated the concept in 1968 with an 18x2 matrix dynamic scattering LCD that used standard discrete MOSFETs, as TFT performance was not adequate at the time. In 1973, T. Peter Brody , J. A. Asars and G. D. Dixon at Westinghouse Research Laboratories developed

1287-572: 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

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1404-423: A base for the image receptor in medical radiography . As of 2013 , all modern high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays. AMOLED displays also contain a TFT layer for active-matrix pixel addressing of individual organic light-emitting diodes . The most beneficial aspect of TFT technology is its use of a separate transistor for each pixel on

1521-452: A blue polarizer, or birefringence which gives them their distinctive appearance. 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 passive-matrix addressed , because the pixel must retain its state between refreshes without

1638-567: 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. Super-IPS was later introduced after in-plane switching with even better response times and color reproduction. Flat-panel display A flat-panel display ( FPD )

1755-968: A car windshield).The first solution-processed TTFTs, based on zinc oxide , were reported in 2003 by researchers at Oregon State University . The Portuguese laboratory CENIMAT at the Universidade Nova de Lisboa has produced the world's first completely transparent TFT at room temperature. CENIMAT also developed the first paper transistor, which may lead to applications such as magazines and journal pages with moving images. Many AMOLED displays use LTPO ( Low-temperature Poly-Crystalline Silicon and Oxide ) TFT transistors. These transistors offer stability at low refresh rates, and variable refresh rates, which allows for power saving displays that do not show visual artifacts. Large OLED displays usually use AOS (amporphous oxide semiconductor) TFT transistors instead, also called oxide TFTs and these are usually based on IGZO. The best known application of thin-film transistors

1872-419: 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

1989-643: A few used plasma displays) and the original Nintendo Game Boy until the mid-1990s, when color active-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

2106-459: 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. After the black resist has been dried in an oven and exposed to UV light through

2223-465: A general-purpose computer display) or fixed images with low information content, which can be displayed or hidden: preset words, digits, and seven-segment displays (as in a digital clock) are all 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

2340-415: A glass substrate to form the cell circuitry to operate the panel. It is usually not possible to use soldering techniques to directly connect the panel to a separate copper-etched circuit board. Instead, interfacing is accomplished using anisotropic conductive film or, for lower densities, elastomeric connectors . Monochrome and later color passive-matrix LCDs were standard in most early laptops (although

2457-514: 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

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2574-412: 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

2691-440: A joint Sanyo and Sanritsu team including Mitsuhiro Yamasaki, S. Suhibuchi and Y. Sasaki fabricated a 3-inch a-SI color LCD TV. The first commercial TFT-based AM LCD product was the 2.1-inch Epson ET-10 (Epson Elf), the first color LCD pocket TV, released in 1984. In 1986, a Hitachi research team led by Akio Mimura demonstrated a low-temperature polycrystalline silicon (LTPS) process for fabricating n-channel TFTs on

2808-449: 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

2925-613: A leading position in the wristwatch market, like Seiko 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. A particular type of such a color LCD was developed by Japan's Sharp Corporation in the 1970s, receiving patents for their inventions, such as a patent by Shinji Kato and Takaaki Miyazaki in May 1975, and then improved by Fumiaki Funada and Masataka Matsuura in December 1975. TFT LCDs similar to

3042-465: 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

3159-400: A mini-LED backlight and quantum dot sheets. LCDs with quantum dot enhancement film or quantum dot color filters were introduced from 2015 to 2018. Quantum dots receive blue light from a backlight and convert it to light that allows LCD panels to offer better color reproduction. Quantum dot color filters are manufactured using photoresists containing quantum dots instead of colored pigments, and

3276-470: A photomask, the unexposed areas are washed away, creating a black grid. Then the same process is repeated with the remaining resists. This fills the holes in the black grid with their corresponding colored resists. Black matrices made in the 1980s and 1990s when most color LCD production was for laptop computers, are made of Chromium due to its high opacity, but due to environmental concerns, manufacturers shifted to black colored photoresist with carbon pigment as

3393-449: 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

3510-464: A reflective display. The common implementations of LCD backlight technology are: 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

3627-661: A relatively flat (for its day) cathode-ray tube setup and would be the first commercially released "flat panel" upon its launch in 1958; the Predicta was a commercial failure. The plasma display panel was invented in 1964 at the University of Illinois , according to The History of Plasma Display Panels. The MOSFET (metal–oxide–semiconductor field-effect transistor, or MOS transistor) was invented by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959, and presented in 1960. Building on their work, Paul K. Weimer at RCA developed

Liquid-crystal display - Misplaced Pages Continue

3744-522: A sharper threshold of the contrast-vs-voltage characteristic than the original TN LCDs. This is important, because pixels are subjected to partial voltages even while not selected. 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, while activated pixels are subjected to voltages above threshold (the voltages according to

3861-476: A significant role in this growth, including as a result of their investments in LCD manufacturers via state-owned investment companies. China had previously imported significant amounts of LCDs, and the growth of its LCD industry decreased prices for other consumer products that use LCDs and led to growth in other sectors like mobile phones. LCDs do not produce light on their own, so they require external light to produce

3978-401: 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

4095-763: A smartwatch). Thin-film transistor TFTs can be fabricated with a wide variety of semiconductor materials. Because it is naturally abundant and well understood, amorphous or polycrystalline silicon were (and still are) used as the semiconductor layer. However, because of the low mobility of amorphous silicon and the large device-to-device variations found in polycrystalline silicon, other materials have been studied for use in TFTs. These include cadmium selenide , metal oxides such as indium gallium zinc oxide (IGZO) or zinc oxide , organic semiconductors , carbon nanotubes , or metal halide perovskites . Because TFTs are grown on inert substrates, rather than on wafers,

4212-638: 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. LCD panels typically use thinly-coated metallic conductive pathways on

4329-529: A video speed-drive scheme that solved the slow response time of STN-LCDs, enabling high-resolution, high-quality, and smooth-moving video images on STN-LCDs. In 1985, Philips inventors Theodorus Welzen and Adrianus de Vaan solved the problem of driving high-resolution STN-LCDs using low-voltage (CMOS-based) drive electronics, allowing the application of high-quality (high resolution and video speed) LCD panels in battery-operated portable products like notebook computers and mobile phones. In 1985, Philips acquired 100% of

4446-412: A visible image. In a transmissive type of LCD, the light source is provided at the back of the glass stack and is called a backlight . Active-matrix LCDs are almost always backlit. Passive LCDs may be backlit but many are reflective as they use a reflective surface or film at the back of the glass stack to utilize ambient light. Transflective LCDs combine the features of a backlit transmissive display and

4563-480: A voltage to a DSM display switches the initially clear transparent liquid crystal layer into a milky turbid state. DSM displays could be operated in transmissive and in reflective mode but they required a considerable current to flow for their operation. George H. Heilmeier was inducted in the National Inventors Hall of Fame and credited with the invention of LCDs. Heilmeier's work is an IEEE Milestone . In

4680-406: Is a flat panel display technology introduced by Samsung under this trademark. Other television set manufacturers such as Sony have used the same technology to enhance the backlighting of LCD TVs already in 2013. Quantum dots create their own unique light when illuminated by a light source of shorter wavelength such as blue LEDs. This type of LED TV enhances the colour gamut of LCD panels, where

4797-449: Is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipment. Flat-panel displays are thin, lightweight, provide better linearity and are capable of higher resolution than typical consumer-grade TVs from earlier eras. They are usually less than 10 centimetres (3.9 in) thick. While the highest resolution for consumer-grade CRT televisions

Liquid-crystal display - Misplaced Pages Continue

4914-662: 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. In contrast, full alphanumeric or variable graphics displays are usually implemented with pixels arranged as

5031-407: 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

5148-422: 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

5265-469: Is based on an electro-hydrodynamic instability forming what are now called "Williams domains" inside the liquid crystal. Building on early MOSFETs , Paul K. Weimer at RCA developed the thin-film transistor (TFT) in 1962. It was a type of MOSFET distinct from the standard bulk MOSFET. In 1964, George H. Heilmeier , who was working at the RCA laboratories on the effect discovered by Richard Williams, achieved

5382-463: Is in TFT LCDs , an implementation of liquid-crystal display technology. Transistors are embedded within the panel itself, reducing crosstalk between pixels and improving image stability. As of 2008 , many color LCD TVs and monitors use this technology. TFT panels are frequently used in digital radiography applications in general radiography. A TFT is used in both direct and indirect capture as

5499-462: Is needed. Displays having a passive-matrix structure use super-twisted nematic STN (invented by Brown Boveri Research Center, Baden, Switzerland, in 1983; scientific details were published) or double-layer STN (DSTN) technology (the latter of which addresses a color-shifting problem with the former), and color-STN (CSTN), in which color is added by using an internal color filter. STN LCDs have been optimized for passive-matrix addressing. They exhibit

5616-432: Is produced by applying appropriate color filters (red, green and blue) to the individual subpixels. LC displays are used in various electronics like watches, calculators, mobile phones, TVs, computer monitors and laptops screens etc. Most earlier large LCD screens were back-lit using a number of CCFL (cold-cathode fluorescent lamps). However, small pocket size devices almost always used LEDs as their illumination source. With

5733-461: 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

5850-423: Is written to the display, the display may be cut from the power while retaining readable images. This has the advantage that such ebooks may be operated for long periods of time powered by only a small battery. 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

5967-513: The super-twisted nematic (STN) structure for 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, U.S. patent 4,634,229 and many more countries. In 1980, Brown Boveri started a 50/50 joint venture with

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6084-537: 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. In 1904, 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

6201-515: The Sony Qualia 005 was the first LED-backlit LCD . The Sony XEL-1 , released in 2007, was the first OLED television. Field-effect LCDs are lightweight, compact, portable, cheap, more reliable, and easier on the eyes than CRT screens. LCD screens use a thin layer of liquid crystal, a liquid that exhibits crystalline properties. It is sandwiched between two glass plates carrying transparent electrodes. Two polarizing films are placed at each side of

6318-681: The Wayback Machine ) with Wolfgang Helfrich and Martin Schadt (then working for the Central Research Laboratories) listed as inventors. Hoffmann-La Roche licensed the invention to Swiss manufacturer 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

6435-434: The thin-film transistor (TFT) in 1962. It was a type of MOSFET distinct from the standard bulk MOSFET. The idea of a TFT-based LCD was conceived by Bernard J. Lechner of RCA Laboratories in 1968. B.J. Lechner, F.J. Marlowe, E.O. Nester and J. Tults demonstrated the concept in 1968 with a dynamic scattering LCD that used standard discrete MOSFETs. The first active-matrix addressed electroluminescent display (ELD)

6552-494: The "Alt & Pleshko" drive scheme). Driving such STN displays according to the Alt & Pleshko drive scheme require very high line addressing voltages. Welzen and de Vaan invented an alternative drive scheme (a non "Alt & Pleshko" drive scheme) requiring much lower voltages, such that the STN display could be driven using low voltage CMOS technologies. White-on-blue LCDs are STN and can use

6669-478: The CRT-based sets, leading to a worldwide energy saving of 600 TWh (2017), equal to 10% of the electricity consumption of all households worldwide or equal to 2 times the energy production of all solar cells in the world. 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

6786-455: The Dutch Philips company, called Videlec. Philips had the required know-how to design and build integrated circuits for the control of large LCD panels. In addition, Philips had better access to markets for electronic components and intended to use LCDs in new product generations of hi-fi, video equipment and telephones. In 1984, Philips researchers Theodorus Welzen and Adrianus de Vaan invented

6903-409: 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

7020-520: The LCD industry. These six companies were fined 1.3 billion dollars by the United States, 650 million Euro by the European Union, and 350 million RMB by China's National Development and Reform Commission . In 2007 the image quality of LCD televisions surpassed the image quality of cathode-ray-tube-based (CRT) TVs. In the fourth quarter of 2007, LCD televisions surpassed CRT TVs in worldwide sales for

7137-401: The LCD. By generating a controlled electric field between electrodes, various segments or pixels of the liquid crystal can be activated, causing changes in their polarizing properties. These polarizing properties depend on the alignment of the liquid-crystal layer and the specific field-effect used, being either Twisted Nematic (TN) , In-Plane Switching (IPS) or Vertical Alignment (VA). Color

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7254-454: The QLED TV they produce can determine what part of the display needs more or less contrast. Samsung also announced a partnership with Microsoft that will promote the new Samsung QLED TV. Volatile displays require that pixels be periodically refreshed to retain their state, even for a static image. As such, a volatile screen needs electrical power, either from mains electricity (being plugged into

7371-542: The R&;D required and never built a working flat panel at that time. The first production flat-panel display was the Aiken tube , developed in the early 1950s and produced in limited numbers in 1958. This saw some use in military systems as a heads up display and as an oscilloscope monitor, but conventional technologies overtook its development. Attempts to commercialize the system for home television use ran into continued problems and

7488-683: The Videlec AG company based in Switzerland. Afterwards, Philips moved the Videlec production lines to the Netherlands. Years later, Philips successfully produced and marketed complete modules (consisting of the LCD screen, microphone, speakers etc.) in high-volume production for the booming mobile phone industry. 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. In 1982, Seiko Epson released

7605-401: The addressing method of these bistable displays is rather complex, a reason why these displays did not make it to the market. That changed when in the 2010 "zero-power" (bistable) LCDs became available. Potentially, passive-matrix addressing can be used with devices if their write/erase characteristics are suitable, which was the case for ebooks which need to show still pictures only. After a page

7722-407: 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

7839-410: 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

7956-621: The benefit of a steady electrical charge. As the number of pixels (and, correspondingly, columns and rows) increases, this type of display becomes less feasible. Slow 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. Citizen, among others, licensed these patents and successfully introduced several STN based LCD pocket televisions on

8073-403: The black matrix material. Another color-generation method used in early color PDAs and some calculators was done by varying the voltage in a Super-twisted nematic LCD, where the variable twist between tighter-spaced plates causes a varying double refraction birefringence , thus changing the hue. They were typically restricted to 3 colors per pixel: orange, green, and blue. The optical effect of

8190-677: 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 . Another report on the origins and history of LCD from a different perspective until 1991 has been published by Hiroshi Kawamoto, available at the IEEE History Center. A description of Swiss contributions to LCD developments, written by Peter J. Wild , can be found at

8307-505: The deposition process must be carried out under relatively low temperatures compared to traditional electronic material processing. Some wide band gap semiconductors, most notable metal oxides, are optically transparent. By also employing transparent substrates, such as glass, and transparent electrodes , such as indium tin oxide (ITO), some TFT devices can be designed to be completely optically transparent. Such transparent TFTs (TTFTs) could be used to enable head-up displays (such as on

8424-474: The display. Because each transistor is small, the amount of charge needed to control it is also small. This allows for very fast re-drawing of the display. This picture does not include the actual light-source (usually cold-cathode fluorescent lamps or white LEDs ), just the TFT-display matrix. In February 1957, John Wallmark of RCA filed a patent for a thin film MOSFET in which germanium monoxide

8541-449: The dominant LCD designs through 2006. In the late 1990s, the LCD industry began shifting away from Japan, towards South Korea and Taiwan , and later on towards China. In this period, Taiwanese, Japanese, and Korean manufacturers were the dominant firms in LCD manufacturing. From 2001 to 2006, Samsung and five other major companies held 53 meetings in Taiwan and South Korea to fix prices in

8658-411: The driving circuitry from the borders of the display to in between the pixels, allowing for narrow bezels. 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

8775-410: 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

8892-569: The first LCD television, the Epson TV Watch, a wristwatch equipped with a small active-matrix LCD television. Sharp Corporation introduced dot matrix TN-LCD in 1983. In 1984, Epson released the ET-10, the first full-color, pocket LCD television. The same year, Citizen Watch , introduced the Citizen Pocket TV, a 2.7-inch color LCD TV, with the first commercial TFT LCD . In 1988, Sharp demonstrated

9009-453: 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. In 1971, the company of Fergason, ILIXCO (now LXD Incorporated ), produced LCDs based on the TN-effect, which soon superseded

9126-507: The first flat 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 1973 and then mass-produced TN LCDs for watches in 1975. Other Japanese companies soon took

9243-412: The first major English language publication Molecular Structure and Properties of Liquid Crystals was published by Dr. George W. Gray . In 1962, Richard Williams of 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

9360-407: The first polarizer of the LCD (invented by Philips researchers Adrianus de Vaan and Paulus Schaareman), generally achieved using so called DBEF films manufactured and supplied by 3M. Improved versions of the prism sheet have a wavy rather than a prismatic structure, and introduce waves laterally into the structure of the sheet while also varying the height of the waves, directing even more light towards

9477-468: The first time. LCD TVs were projected to account 50% of the 200 million TVs to be shipped globally in 2006, according to Displaybank . In October 2011, Toshiba announced 2560 × 1600 pixels on a 6.1-inch (155 mm) LCD panel, suitable for use in a tablet computer , especially for Chinese character display. The 2010s also saw the wide adoption of TGP (Tracking Gate-line in Pixel), which moves

9594-518: The image is still generated by the LCD. In the view of Samsung, quantum dot displays for large-screen TVs are expected to become more popular than the OLED displays in the coming years; Firms like Nanoco and Nanosys compete to provide the QD materials. In the meantime, Samsung Galaxy devices such as smartphones are still equipped with OLED displays manufactured by Samsung as well. Samsung explains on their website that

9711-417: The improvement of LEDs, almost all new displays are now equipped with LED backlight technology. The image is still generated by the LCD layer. A plasma display consists of two glass plates separated by a thin gap filled with a gas such as neon . Each of these plates has several parallel electrodes running across it. The electrodes on the two plates are at right angles to each other. A voltage applied between

9828-472: The inventors worked, assigns these patents to Merck KGaA, Darmstadt, a supplier of LC substances. In 1992, shortly thereafter, engineers at 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. The first wall-mountable LCD TV was introduced by Sharp Corporation in 1992. Hitachi also improved

9945-521: 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)

10062-700: The light of the backlight uniformly, while a mirror is placed behind the light guide plate to direct all light forwards. The prism sheet with its diffuser sheets are placed on top of the light guide plate. The DBEF polarizers consist of a large stack of uniaxial oriented birefringent films that reflect the former absorbed polarization mode of the light. DBEF polarizers using uniaxial oriented polymerized liquid crystals (birefringent polymers or birefringent glue) were invented in 1989 by Philips researchers Dirk Broer, Adrianus de Vaan and Joerg Brambring. The combination of such reflective polarizers, and LED dynamic backlight control make today's LCD televisions far more efficient than

10179-449: 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. An example is a mixture of 2-(4-alkoxyphenyl)-5-alkylpyrimidine with cyanobiphenyl, patented by Merck and Sharp Corporation . The patent that covered that specific mixture has expired. Most color LCD systems use

10296-466: The market. 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. Since a pixel may be either in an on-state or in an off state at the moment new information needs to be written to that particular pixel,

10413-454: The other hand, static flat-panel displays rely on materials whose color states are bistable, such as displays that make use of e-ink technology , and as such retain content even when power is removed. The first engineering proposal for a flat-panel TV was by General Electric in 1954 as a result of its work on radar monitors. The publication of their findings gave all the basics of future flat-panel TVs and monitors. But GE did not continue with

10530-557: The phosphor glow. An OLED (organic light-emitting diode) is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound which emits light in response to an electric current. This layer of organic semiconductor is situated between two electrodes; typically, at least one of these electrodes is transparent. OLEDs are used to create digital displays in devices such as television screens, computer monitors, portable systems such as mobile phones, handheld game consoles and PDAs. QLED or quantum dot LED

10647-964: The polarizer arrangement. For example, a character positive LCD with a backlight has black lettering on a background that is the color of the backlight, and a character negative LCD has a black background with the letters being of the same color as the backlight. 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. LCDs are not subject to screen burn-in like on CRTs. However, LCDs are still susceptible to image persistence . Each pixel of an LCD typically consists of

10764-475: 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 first wristwatch with TN-LCD was launched on the market: The Gruen Teletime which was a four digit display watch. In 1972, the concept of the active-matrix thin-film transistor (TFT) liquid-crystal display panel

10881-508: 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, then improved in 1977 by a Sharp team consisting of Kohei Kishi, Hirosaku Nonomura, Keiichiro Shimizu, and Tomio Wada. However, these TFT-LCDs were not yet ready for use in products, as problems with the materials for the TFTs were not yet solved. In 1983, researchers at Brown, Boveri & Cie (BBC) Research Center, Switzerland , invented

10998-451: The quantum dots can have a special structure to improve their application onto the color filter. Quantum dot color filters offer superior light transmission over quantum dot enhancement films. In the 2020s, China became the largest manufacturer of LCDs and Chinese firms had a 40% share of the global market. Chinese firms that developed into world industry leaders included BOE Technology , TCL-CSOT, TIANMA, and Visionox. Local governments had

11115-532: The response time is reduced to just 5 milliseconds when compared with normal STN LCD panels which have a response time of 16 milliseconds. FSC LCDs contain a Chip-On-Glass driver IC can also be used with a capacitive touchscreen. This technique can also be applied in displays meant to show images, as it can offer higher light transmission and thus potential for reduced power consumption in the backlight due to omission of color filters in LCDs. Samsung introduced UFB (Ultra Fine & Bright) displays back in 2002, utilized

11232-508: 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 thin-film transistor (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 colored photoresists (resists) are used to create color filters. All resists contain

11349-412: The screen and reducing aliasing or moiré between the structure of the prism sheet and the subpixels of the LCD. A wavy structure is easier to mass-produce than a prismatic one using conventional diamond machine tools, which are used to make the rollers used to imprint the wavy structure into plastic sheets, thus producing prism sheets. A diffuser sheet is placed on both sides of the prism sheet to distribute

11466-499: The semiconductor must be deposited in a dedicated process. A variety of techniques are used to deposit semiconductors in TFTs. These include chemical vapor deposition (CVD), atomic layer deposition (ALD), and sputtering . The semiconductor can also be deposited from solution, via techniques such as printing or spray coating. Solution-based techniques are hoped to lead to low-cost, mechanically flexible electronics. Because typical substrates will deform or melt at high temperatures,

11583-557: 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,

11700-524: 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

11817-400: 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 dynamic scattering mode (DSM). Application of

11934-624: The system was never released commercially. Dennis Gabor , better known as the inventor of holography , patented a flat-screen CRT in 1958. This was substantially similar to Aiken's concept, and led to a years-long patent battle . By the time the lawsuits were complete, with Aiken's patent applying in the US and Gabor's in the UK, the commercial aspects had long lapsed, and the two became friends. Around this time, Clive Sinclair came across Gabor's work and began an ultimately unsuccessful decade-long effort to commercialize it. The Philco Predicta featured

12051-407: The two electrodes one on each plate causes a small segment of gas at the two electrodes to glow. The glow of gas segments is maintained by a lower voltage that is continuously applied to all electrodes. By 2010, consumer plasma displays had been discontinued by numerous manufacturers. In an electroluminescent display (ELD), the image is created by applying electrical signals to the plates which make

12168-434: The user to interact with the display in a natural manner. For example, modern smartphone displays often use OLED panels, with capacitive touch screens . Flat-panel displays can be divided into two display device categories: volatile and static. The former requires that pixels be periodically electronically refreshed to retain their state (e.g. liquid-crystal displays (LCD)), and can only show an image when it has power. On

12285-625: 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

12402-499: 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

12519-635: Was 1080i , many interactive flat panels in the 2020s are capable of 1080p and 4K resolution. In the 2010s, portable consumer electronics such as laptops, mobile phones, and portable cameras have used flat-panel displays since they consume less power and are lightweight. As of 2016, flat-panel displays have almost completely replaced CRT displays. Most 2010s-era flat-panel displays use LCD or light-emitting diode (LED) technologies, sometimes combined. Most LCD screens are back-lit with color filters used to display colors. In many cases, flat-panel displays are combined with touch screen technology, which allows

12636-549: Was a revolution in digital display technology, replacing the Nixie tube for numeric displays and becoming the basis for later LED displays. In 1977, James P Mitchell prototyped and later demonstrated what was perhaps the earliest monochromatic flat-panel LED television display. Ching W. Tang and Steven Van Slyke at Eastman Kodak built the first practical organic LED (OLED) device in 1987. In 2003, Hynix produced an organic EL driver capable of lighting in 4,096 colors. In 2004,

12753-439: Was conceived by Bernard Lechner of RCA Laboratories in 1968. Lechner, F.J. Marlowe, E.O. Nester and J. Tults demonstrated the concept in 1968 with an 18x2 matrix 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 Archived March 9, 2021, at

12870-469: Was developed by Hewlett-Packard (HP) and introduced in 1968. It was the result of research and development (R&D) on practical LED technology between 1962 and 1968, by a research team under Howard C. Borden, Gerald P. Pighini, and Mohamed M. Atalla , at HP Associates and HP Labs . In February 1969, they introduced the HP Model 5082-7000 Numeric Indicator. It was the first alphanumeric LED display, and

12987-673: Was limited or has been ultimately abandoned: Static flat-panel displays rely on materials whose color states are bistable . This means that the image they hold requires no energy to maintain, but instead requires energy to change. This results in a much more energy-efficient display, but with a tendency toward slow refresh rates which are undesirable in an interactive display. Bistable flat-panel displays are beginning deployment in limited applications ( cholesteric liquid-crystal displays, manufactured by Magink, in outdoor advertising; electrophoretic displays in e-book reader devices from Sony and iRex; anlabels; interferometric modulator displays in

13104-523: Was made using TFTs by T. Peter Brody 's Thin-Film Devices department at Westinghouse Electric Corporation in 1968. In 1973, Brody, J. A. Asars and G. D. Dixon at Westinghouse Research Laboratories demonstrated the first thin-film-transistor liquid-crystal display (TFT LCD). Brody and Fang-Chen Luo demonstrated the first flat active-matrix liquid-crystal display (AM LCD) using TFTs in 1974. By 1982, pocket LCD TVs based on LCD technology were developed in Japan. The 2.1-inch Epson ET-10 Epson Elf

13221-453: Was never realized, due to complications in controlling the compound semiconductor thin film material properties, and device reliability over large areas. A breakthrough in TFT research came with the development of the amorphous silicon (a-Si) TFT by P.G. le Comber, W.E. Spear and A. Ghaith at the University of Dundee in 1979. They reported the first functional TFT made from hydrogenated a-Si with

13338-499: Was prototyped in the United States by T. Peter Brody 's team at Westinghouse , in Pittsburgh, Pennsylvania . In 1973, Brody, J. A. Asars and G. D. Dixon at Westinghouse Research Laboratories demonstrated the first thin-film-transistor liquid-crystal display (TFT LCD). As of 2013, all modern high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays. Brody and Fang-Chen Luo demonstrated

13455-452: Was the first color LCD pocket TV, released in 1984. In 1988, a Sharp research team led by engineer T. Nagayasu demonstrated a 14-inch full-color LCD, which convinced the electronics industry that LCD would eventually replace CRTs as the standard television display technology . As of 2013 , all modern high-resolution and high-quality electronic visual display devices use TFT-based active-matrix displays. The first usable LED display

13572-543: Was to use interdigital electrodes on one glass substrate only to produce an electric field essentially parallel to the glass substrates. To take full advantage of the properties of this In Plane Switching (IPS) technology further work was needed. After thorough analysis, details of advantageous embodiments are filed in Germany by Guenter Baur et al. and patented in various countries. The Fraunhofer Institute ISE in Freiburg, where

13689-447: Was used as a gate dielectric. Paul K. Weimer , also of RCA implemented Wallmark's ideas and developed the thin-film transistor (TFT) in 1962, a type of MOSFET distinct from the standard bulk MOSFET. It was made with thin films of cadmium selenide and cadmium sulfide . In 1966, T.P. Brody and H.E. Kunig at Westinghouse Electric fabricated indium arsenide (InAs) MOS TFTs in both depletion and enhancement modes . The idea of

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