lcd touch screen wiki brands

Flat-panel displays are thin panels of glass or plastic used for electronically displaying text, images, or video. Liquid crystal displays (LCD), OLED (organic light emitting diode) and microLED displays are not quite the same; since LCD uses a liquid crystal that reacts to an electric current blocking light or allowing it to pass through the panel, whereas OLED/microLED displays consist of electroluminescent organic/inorganic materials that generate light when a current is passed through the material. LCD, OLED and microLED displays are driven using LTPS, IGZO, LTPO, and A-Si TFT transistor technologies as their backplane using ITO to supply current to the transistors and in turn to the liquid crystal or electroluminescent material. Segment and passive OLED and LCD displays do not use a backplane but use indium tin oxide (ITO), a transparent conductive material, to pass current to the electroluminescent material or liquid crystal. In LCDs, there is an even layer of liquid crystal throughout the panel whereas an OLED display has the electroluminescent material only where it is meant to light up. OLEDs, LCDs and microLEDs can be made flexible and transparent, but LCDs require a backlight because they cannot emit light on their own like OLEDs and microLEDs.
Liquid-crystal display (or LCD) is a thin, flat panel used for electronically displaying information such as text, images, and moving pictures. They are usually made of glass but they can also be made out of plastic. Some manufacturers make transparent LCD panels and special sequential color segment LCDs that have higher than usual refresh rates and an RGB backlight. The backlight is synchronized with the display so that the colors will show up as needed. The list of LCD manufacturers:
Organic light emitting diode (or OLED displays) is a thin, flat panel made of glass or plastic used for electronically displaying information such as text, images, and moving pictures. OLED panels can also take the shape of a light panel, where red, green and blue light emitting materials are stacked to create a white light panel. OLED displays can also be made transparent and/or flexible and these transparent panels are available on the market and are widely used in smartphones with under-display optical fingerprint sensors. LCD and OLED displays are available in different shapes, the most prominent of which is a circular display, which is used in smartwatches. The list of OLED display manufacturers:
MicroLED displays is an emerging flat-panel display technology consisting of arrays of microscopic LEDs forming the individual pixel elements. Like OLED, microLED offers infinite contrast ratio, but unlike OLED, microLED is immune to screen burn-in, and consumes less power while having higher light output, as it uses LEDs instead of organic electroluminescent materials, The list of MicroLED display manufacturers:
LCDs are made in a glass substrate. For OLED, the substrate can also be plastic. The size of the substrates are specified in generations, with each generation using a larger substrate. For example, a 4th generation substrate is larger in size than a 3rd generation substrate. A larger substrate allows for more panels to be cut from a single substrate, or for larger panels to be made, akin to increasing wafer sizes in the semiconductor industry.
"Samsung Display has halted local Gen-8 LCD lines: sources". THE ELEC, Korea Electronics Industry Media. August 16, 2019. Archived from the original on April 3, 2020. Retrieved December 18, 2019.
"TCL to Build World"s Largest Gen 11 LCD Panel Factory". www.businesswire.com. May 19, 2016. Archived from the original on April 2, 2018. Retrieved April 1, 2018.
"Panel Manufacturers Start to Operate Their New 8th Generation LCD Lines". 대한민국 IT포털의 중심! 이티뉴스. June 19, 2017. Archived from the original on June 30, 2019. Retrieved June 30, 2019.
"Samsung Display Considering Halting Some LCD Production Lines". 비즈니스코리아 - BusinessKorea. August 16, 2019. Archived from the original on April 5, 2020. Retrieved December 19, 2019.
Herald, The Korea (July 6, 2016). "Samsung Display accelerates transition from LCD to OLED". www.koreaherald.com. Archived from the original on April 1, 2018. Retrieved April 1, 2018.
"China"s BOE to have world"s largest TFT-LCD+AMOLED capacity in 2019". ihsmarkit.com. 2017-03-22. Archived from the original on 2019-08-16. Retrieved 2019-08-17.
![]()
A touchscreen or touch screen is the assembly of both an input ("touch panel") and output ("display") device. The touch panel is normally layered on the top of an electronic visual display of an electronic device.
A user can give input or control the information processing system through simple or multi-touch gestures by touching the screen with a special stylus or one or more fingers.zooming to increase the text size.
The touchscreen enables the user to interact directly with what is displayed, rather than using a mouse, touchpad, or other such devices (other than a stylus, which is optional for most modern touchscreens).
Touchscreens are common in devices such as smartphones, handheld game consoles, personal computers, electronic voting machines, automated teller machines and point-of-sale (POS) systems. They can also be attached to computers or, as terminals, to networks. They play a prominent role in the design of digital appliances such as personal digital assistants (PDAs) and some e-readers. Touchscreens are also important in educational settings such as classrooms or on college campuses.
The popularity of smartphones, tablets, and many types of information appliances is driving the demand and acceptance of common touchscreens for portable and functional electronics. Touchscreens are found in the medical field, heavy industry, automated teller machines (ATMs), and kiosks such as museum displays or room automation, where keyboard and mouse systems do not allow a suitably intuitive, rapid, or accurate interaction by the user with the display"s content.
Historically, the touchscreen sensor and its accompanying controller-based firmware have been made available by a wide array of after-market system integrators, and not by display, chip, or motherboard manufacturers. Display manufacturers and chip manufacturers have acknowledged the trend toward acceptance of touchscreens as a user interface component and have begun to integrate touchscreens into the fundamental design of their products.
The prototypeCERNFrank Beck, a British electronics engineer, for the control room of CERN"s accelerator SPS (Super Proton Synchrotron). This was a further development of the self-capacitance screen (right), also developed by Stumpe at CERN
One predecessor of the modern touch screen includes stylus based systems. In 1946, a patent was filed by Philco Company for a stylus designed for sports telecasting which, when placed against an intermediate cathode ray tube display (CRT) would amplify and add to the original signal. Effectively, this was used for temporarily drawing arrows or circles onto a live television broadcast, as described in US 2487641A, Denk, William E, "Electronic pointer for television images", issued 1949-11-08. Later inventions built upon this system to free telewriting styli from their mechanical bindings. By transcribing what a user draws onto a computer, it could be saved for future use. See US 3089918A, Graham, Robert E, "Telewriting apparatus", issued 1963-05-14.
The first version of a touchscreen which operated independently of the light produced from the screen was patented by AT&T Corporation US 3016421A, Harmon, Leon D, "Electrographic transmitter", issued 1962-01-09. This touchscreen utilized a matrix of collimated lights shining orthogonally across the touch surface. When a beam is interrupted by a stylus, the photodetectors which no longer are receiving a signal can be used to determine where the interruption is. Later iterations of matrix based touchscreens built upon this by adding more emitters and detectors to improve resolution, pulsing emitters to improve optical signal to noise ratio, and a nonorthogonal matrix to remove shadow readings when using multi-touch.
The first finger driven touch screen was developed by Eric Johnson, of the Royal Radar Establishment located in Malvern, England, who described his work on capacitive touchscreens in a short article published in 1965Frank Beck and Bent Stumpe, engineers from CERN (European Organization for Nuclear Research), developed a transparent touchscreen in the early 1970s,In the mid-1960s, another precursor of touchscreens, an ultrasonic-curtain-based pointing device in front of a terminal display, had been developed by a team around Rainer Mallebrein[de] at Telefunken Konstanz for an air traffic control system.Einrichtung" ("touch input facility") for the SIG 50 terminal utilizing a conductively coated glass screen in front of the display.
In 1972, a group at the University of Illinois filed for a patent on an optical touchscreenMagnavox Plato IV Student Terminal and thousands were built for this purpose. These touchscreens had a crossed array of 16×16 infrared position sensors, each composed of an LED on one edge of the screen and a matched phototransistor on the other edge, all mounted in front of a monochrome plasma display panel. This arrangement could sense any fingertip-sized opaque object in close proximity to the screen. A similar touchscreen was used on the HP-150 starting in 1983. The HP 150 was one of the world"s earliest commercial touchscreen computers.infrared transmitters and receivers around the bezel of a 9-inch Sony cathode ray tube (CRT).
In 1977, an American company, Elographics – in partnership with Siemens – began work on developing a transparent implementation of an existing opaque touchpad technology, U.S. patent No. 3,911,215, October 7, 1975, which had been developed by Elographics" founder George Samuel Hurst.World"s Fair at Knoxville in 1982.
In 1984, Fujitsu released a touch pad for the Micro 16 to accommodate the complexity of kanji characters, which were stored as tiled graphics.Sega released the Terebi Oekaki, also known as the Sega Graphic Board, for the SG-1000 video game console and SC-3000 home computer. It consisted of a plastic pen and a plastic board with a transparent window where pen presses are detected. It was used primarily with a drawing software application.
Touch-sensitive control-display units (CDUs) were evaluated for commercial aircraft flight decks in the early 1980s. Initial research showed that a touch interface would reduce pilot workload as the crew could then select waypoints, functions and actions, rather than be "head down" typing latitudes, longitudes, and waypoint codes on a keyboard. An effective integration of this technology was aimed at helping flight crews maintain a high level of situational awareness of all major aspects of the vehicle operations including the flight path, the functioning of various aircraft systems, and moment-to-moment human interactions.
In the early 1980s, General Motors tasked its Delco Electronics division with a project aimed at replacing an automobile"s non-essential functions (i.e. other than throttle, transmission, braking, and steering) from mechanical or electro-mechanical systems with solid state alternatives wherever possible. The finished device was dubbed the ECC for "Electronic Control Center", a digital computer and software control system hardwired to various peripheral sensors, servos, solenoids, antenna and a monochrome CRT touchscreen that functioned both as display and sole method of input.stereo, fan, heater and air conditioner controls and displays, and was capable of providing very detailed and specific information about the vehicle"s cumulative and current operating status in real time. The ECC was standard equipment on the 1985–1989 Buick Riviera and later the 1988–1989 Buick Reatta, but was unpopular with consumers—partly due to the technophobia of some traditional Buick customers, but mostly because of costly technical problems suffered by the ECC"s touchscreen which would render climate control or stereo operation impossible.
Multi-touch technology began in 1982, when the University of Toronto"s Input Research Group developed the first human-input multi-touch system, using a frosted-glass panel with a camera placed behind the glass. In 1985, the University of Toronto group, including Bill Buxton, developed a multi-touch tablet that used capacitance rather than bulky camera-based optical sensing systems (see History of multi-touch).
The first commercially available graphical point-of-sale (POS) software was demonstrated on the 16-bit Atari 520ST color computer. It featured a color touchscreen widget-driven interface.COMDEX expo in 1986.
In 1987, Casio launched the Casio PB-1000 pocket computer with a touchscreen consisting of a 4×4 matrix, resulting in 16 touch areas in its small LCD graphic screen.
Touchscreens had a bad reputation of being imprecise until 1988. Most user-interface books would state that touchscreen selections were limited to targets larger than the average finger. At the time, selections were done in such a way that a target was selected as soon as the finger came over it, and the corresponding action was performed immediately. Errors were common, due to parallax or calibration problems, leading to user frustration. "Lift-off strategy"University of Maryland Human–Computer Interaction Lab (HCIL). As users touch the screen, feedback is provided as to what will be selected: users can adjust the position of the finger, and the action takes place only when the finger is lifted off the screen. This allowed the selection of small targets, down to a single pixel on a 640×480 Video Graphics Array (VGA) screen (a standard of that time).
Sears et al. (1990)human–computer interaction of the time, describing gestures such as rotating knobs, adjusting sliders, and swiping the screen to activate a switch (or a U-shaped gesture for a toggle switch). The HCIL team developed and studied small touchscreen keyboards (including a study that showed users could type at 25 wpm on a touchscreen keyboard), aiding their introduction on mobile devices. They also designed and implemented multi-touch gestures such as selecting a range of a line, connecting objects, and a "tap-click" gesture to select while maintaining location with another finger.
In 1990, HCIL demonstrated a touchscreen slider,lock screen patent litigation between Apple and other touchscreen mobile phone vendors (in relation to
An early attempt at a handheld game console with touchscreen controls was Sega"s intended successor to the Game Gear, though the device was ultimately shelved and never released due to the expensive cost of touchscreen technology in the early 1990s.
Touchscreens would not be popularly used for video games until the release of the Nintendo DS in 2004.Apple Watch being released with a force-sensitive display in April 2015.
In 2007, 93% of touchscreens shipped were resistive and only 4% were projected capacitance. In 2013, 3% of touchscreens shipped were resistive and 90% were projected capacitance.
A resistive touchscreen panel comprises several thin layers, the most important of which are two transparent electrically resistive layers facing each other with a thin gap between. The top layer (that which is touched) has a coating on the underside surface; just beneath it is a similar resistive layer on top of its substrate. One layer has conductive connections along its sides, the other along top and bottom. A voltage is applied to one layer and sensed by the other. When an object, such as a fingertip or stylus tip, presses down onto the outer surface, the two layers touch to become connected at that point.voltage dividers, one axis at a time. By rapidly switching between each layer, the position of pressure on the screen can be detected.
Resistive touch is used in restaurants, factories and hospitals due to its high tolerance for liquids and contaminants. A major benefit of resistive-touch technology is its low cost. Additionally, as only sufficient pressure is necessary for the touch to be sensed, they may be used with gloves on, or by using anything rigid as a finger substitute. Disadvantages include the need to press down, and a risk of damage by sharp objects. Resistive touchscreens also suffer from poorer contrast, due to having additional reflections (i.e. glare) from the layers of material placed over the screen.3DS family, and the Wii U GamePad.
Surface acoustic wave (SAW) technology uses ultrasonic waves that pass over the touchscreen panel. When the panel is touched, a portion of the wave is absorbed. The change in ultrasonic waves is processed by the controller to determine the position of the touch event. Surface acoustic wave touchscreen panels can be damaged by outside elements. Contaminants on the surface can also interfere with the functionality of the touchscreen.
The Casio TC500 Capacitive touch sensor watch from 1983, with angled light exposing the touch sensor pads and traces etched onto the top watch glass surface.
A capacitive touchscreen panel consists of an insulator, such as glass, coated with a transparent conductor, such as indium tin oxide (ITO).electrostatic field, measurable as a change in capacitance. Different technologies may be used to determine the location of the touch. The location is then sent to the controller for processing. Touchscreens that use silver instead of ITO exist, as ITO causes several environmental problems due to the use of indium.complementary metal–oxide–semiconductor (CMOS) application-specific integrated circuit (ASIC) chip, which in turn usually sends the signals to a CMOS digital signal processor (DSP) for processing.
Unlike a resistive touchscreen, some capacitive touchscreens cannot be used to detect a finger through electrically insulating material, such as gloves. This disadvantage especially affects usability in consumer electronics, such as touch tablet PCs and capacitive smartphones in cold weather when people may be wearing gloves. It can be overcome with a special capacitive stylus, or a special-application glove with an embroidered patch of conductive thread allowing electrical contact with the user"s fingertip.
A low-quality switching-mode power supply unit with an accordingly unstable, noisy voltage may temporarily interfere with the precision, accuracy and sensitivity of capacitive touch screens.
Some capacitive display manufacturers continue to develop thinner and more accurate touchscreens. Those for mobile devices are now being produced with "in-cell" technology, such as in Samsung"s Super AMOLED screens, that eliminates a layer by building the capacitors inside the display itself. This type of touchscreen reduces the visible distance between the user"s finger and what the user is touching on the screen, reducing the thickness and weight of the display, which is desirable in smartphones.
In this basic technology, only one side of the insulator is coated with a conductive layer. A small voltage is applied to the layer, resulting in a uniform electrostatic field. When a conductor, such as a human finger, touches the uncoated surface, a capacitor is dynamically formed. The sensor"s controller can determine the location of the touch indirectly from the change in the capacitance as measured from the four corners of the panel. As it has no moving parts, it is moderately durable but has limited resolution, is prone to false signals from parasitic capacitive coupling, and needs calibration during manufacture. It is therefore most often used in simple applications such as industrial controls and kiosks.
This diagram shows how eight inputs to a lattice touchscreen or keypad creates 28 unique intersections, as opposed to 16 intersections created using a standard x/y multiplexed touchscreen .
Projected capacitive touch (PCT; also PCAP) technology is a variant of capacitive touch technology but where sensitivity to touch, accuracy, resolution and speed of touch have been greatly improved by the use of a simple form of
Some modern PCT touch screens are composed of thousands of discrete keys,etching a single conductive layer to form a grid pattern of electrodes, by etching two separate, perpendicular layers of conductive material with parallel lines or tracks to form a grid, or by forming an x/y grid of fine, insulation coated wires in a single layer . The number of fingers that can be detected simultaneously is determined by the number of cross-over points (x * y) . However, the number of cross-over points can be almost doubled by using a diagonal lattice layout, where, instead of x elements only ever crossing y elements, each conductive element crosses every other element .
In some designs, voltage applied to this grid creates a uniform electrostatic field, which can be measured. When a conductive object, such as a finger, comes into contact with a PCT panel, it distorts the local electrostatic field at that point. This is measurable as a change in capacitance. If a finger bridges the gap between two of the "tracks", the charge field is further interrupted and detected by the controller. The capacitance can be changed and measured at every individual point on the grid. This system is able to accurately track touches.
Unlike traditional capacitive touch technology, it is possible for a PCT system to sense a passive stylus or gloved finger. However, moisture on the surface of the panel, high humidity, or collected dust can interfere with performance.
These environmental factors, however, are not a problem with "fine wire" based touchscreens due to the fact that wire based touchscreens have a much lower "parasitic" capacitance, and there is greater distance between neighbouring conductors.
This is a common PCT approach, which makes use of the fact that most conductive objects are able to hold a charge if they are very close together. In mutual capacitive sensors, a capacitor is inherently formed by the row trace and column trace at each intersection of the grid. A 16×14 array, for example, would have 224 independent capacitors. A voltage is applied to the rows or columns. Bringing a finger or conductive stylus close to the surface of the sensor changes the local electrostatic field, which in turn reduces the mutual capacitance. The capacitance change at every individual point on the grid can be measured to accurately determine the touch location by measuring the voltage in the other axis. Mutual capacitance allows multi-touch operation where multiple fingers, palms or styli can be accurately tracked at the same time.
Self-capacitive touch screen layers are used on mobile phones such as the Sony Xperia Sola,Samsung Galaxy S4, Galaxy Note 3, Galaxy S5, and Galaxy Alpha.
Self capacitance is far more sensitive than mutual capacitance and is mainly used for single touch, simple gesturing and proximity sensing where the finger does not even have to touch the glass surface.
Capacitive touchscreens do not necessarily need to be operated by a finger, but until recently the special styli required could be quite expensive to purchase. The cost of this technology has fallen greatly in recent years and capacitive styli are now widely available for a nominal charge, and often given away free with mobile accessories. These consist of an electrically conductive shaft with a soft conductive rubber tip, thereby resistively connecting the fingers to the tip of the stylus.
Infrared sensors mounted around the display watch for a user"s touchscreen input on this PLATO V terminal in 1981. The monochromatic plasma display"s characteristic orange glow is illustrated.
An infrared touchscreen uses an array of X-Y infrared LED and photodetector pairs around the edges of the screen to detect a disruption in the pattern of LED beams. These LED beams cross each other in vertical and horizontal patterns. This helps the sensors pick up the exact location of the touch. A major benefit of such a system is that it can detect essentially any opaque object including a finger, gloved finger, stylus or pen. It is generally used in outdoor applications and POS systems that cannot rely on a conductor (such as a bare finger) to activate the touchscreen. Unlike capacitive touchscreens, infrared touchscreens do not require any patterning on the glass which increases durability and optical clarity of the overall system. Infrared touchscreens are sensitive to dirt and dust that can interfere with the infrared beams, and suffer from parallax in curved surfaces and accidental press when the user hovers a finger over the screen while searching for the item to be selected.
A translucent acrylic sheet is used as a rear-projection screen to display information. The edges of the acrylic sheet are illuminated by infrared LEDs, and infrared cameras are focused on the back of the sheet. Objects placed on the sheet are detectable by the cameras. When the sheet is touched by the user, frustrated total internal reflection results in leakage of infrared light which peaks at the points of maximum pressure, indicating the user"s touch location. Microsoft"s PixelSense tablets use this technology.
Optical touchscreens are a relatively modern development in touchscreen technology, in which two or more image sensors (such as CMOS sensors) are placed around the edges (mostly the corners) of the screen. Infrared backlights are placed in the sensor"s field of view on the opposite side of the screen. A touch blocks some lights from the sensors, and the location and size of the touching object can be calculated (see visual hull). This technology is growing in popularity due to its scalability, versatility, and affordability for larger touchscreens.
Introduced in 2002 by 3M, this system detects a touch by using sensors to measure the piezoelectricity in the glass. Complex algorithms interpret this information and provide the actual location of the touch.
The key to this technology is that a touch at any one position on the surface generates a sound wave in the substrate which then produces a unique combined signal as measured by three or more tiny transducers attached to the edges of the touchscreen. The digitized signal is compared to a list corresponding to every position on the surface, determining the touch location. A moving touch is tracked by rapid repetition of this process. Extraneous and ambient sounds are ignored since they do not match any stored sound profile. The technology differs from other sound-based technologies by using a simple look-up method rather than expensive signal-processing hardware. As with the dispersive signal technology system, a motionless finger cannot be detected after the initial touch. However, for the same reason, the touch recognition is not disrupted by any resting objects. The technology was created by SoundTouch Ltd in the early 2000s, as described by the patent family EP1852772, and introduced to the market by Tyco International"s Elo division in 2006 as Acoustic Pulse Recognition.
There are several principal ways to build a touchscreen. The key goals are to recognize one or more fingers touching a display, to interpret the command that this represents, and to communicate the command to the appropriate application.
Dispersive-signal technology measures the piezoelectric effect—the voltage generated when mechanical force is applied to a material—that occurs chemically when a strengthened glass substrate is touched.
There are two infrared-based approaches. In one, an array of sensors detects a finger touching or almost touching the display, thereby interrupting infrared light beams projected over the screen. In the other, bottom-mounted infrared cameras record heat from screen touches.
The development of multi-touch screens facilitated the tracking of more than one finger on the screen; thus, operations that require more than one finger are possible. These devices also allow multiple users to interact with the touchscreen simultaneously.
With the growing use of touchscreens, the cost of touchscreen technology is routinely absorbed into the products that incorporate it and is nearly eliminated. Touchscreen technology has demonstrated reliability and is found in airplanes, automobiles, gaming consoles, machine control systems, appliances, and handheld display devices including cellphones; the touchscreen market for mobile devices was projected to produce US$5 billion by 2009.
The ability to accurately point on the screen itself is also advancing with the emerging graphics tablet-screen hybrids. Polyvinylidene fluoride (PVDF) plays a major role in this innovation due its high piezoelectric properties, which allow the tablet to sense pressure, making such things as digital painting behave more like paper and pencil.
TapSense, announced in October 2011, allows touchscreens to distinguish what part of the hand was used for input, such as the fingertip, knuckle and fingernail. This could be used in a variety of ways, for example, to copy and paste, to capitalize letters, to activate different drawing modes, etc.
For touchscreens to be effective input devices, users must be able to accurately select targets and avoid accidental selection of adjacent targets. The design of touchscreen interfaces should reflect technical capabilities of the system, ergonomics, cognitive psychology and human physiology.
Guidelines for touchscreen designs were first developed in the 2000s, based on early research and actual use of older systems, typically using infrared grids—which were highly dependent on the size of the user"s fingers. These guidelines are less relevant for the bulk of modern touch devices which use capacitive or resistive touch technology.
Much more important is the accuracy humans have in selecting targets with their finger or a pen stylus. The accuracy of user selection varies by position on the screen: users are most accurate at the center, less so at the left and right edges, and least accurate at the top edge and especially the bottom edge. The R95 accuracy (required radius for 95% target accuracy) varies from 7 mm (0.28 in) in the center to 12 mm (0.47 in) in the lower corners.
This user inaccuracy is a result of parallax, visual acuity and the speed of the feedback loop between the eyes and fingers. The precision of the human finger alone is much, much higher than this, so when assistive technologies are provided—such as on-screen magnifiers—users can move their finger (once in contact with the screen) with precision as small as 0.1 mm (0.004 in).
Users of handheld and portable touchscreen devices hold them in a variety of ways, and routinely change their method of holding and selection to suit the position and type of input. There are four basic types of handheld interaction:
Touchscreens are often used with haptic response systems. A common example of this technology is the vibratory feedback provided when a button on the touchscreen is tapped. Haptics are used to improve the user"s experience with touchscreens by providing simulated tactile feedback, and can be designed to react immediately, partly countering on-screen response latency. Research from the University of Glasgow (Brewster, Chohan, and Brown, 2007; and more recently Hogan) demonstrates that touchscreen users reduce input errors (by 20%), increase input speed (by 20%), and lower their cognitive load (by 40%) when touchscreens are combined with haptics or tactile feedback. On top of this, a study conducted in 2013 by Boston College explored the effects that touchscreens haptic stimulation had on triggering psychological ownership of a product. Their research concluded that a touchscreens ability to incorporate high amounts of haptic involvement resulted in customers feeling more endowment to the products they were designing or buying. The study also reported that consumers using a touchscreen were willing to accept a higher price point for the items they were purchasing.
Unsupported touchscreens are still fairly common in applications such as ATMs and data kiosks, but are not an issue as the typical user only engages for brief and widely spaced periods.
Touchscreens can suffer from the problem of fingerprints on the display. This can be mitigated by the use of materials with optical coatings designed to reduce the visible effects of fingerprint oils. Most modern smartphones have oleophobic coatings, which lessen the amount of oil residue. Another option is to install a matte-finish anti-glare screen protector, which creates a slightly roughened surface that does not easily retain smudges.
Touchscreens do not work most of the time when the user wears gloves. The thickness of the glove and the material they are made of play a significant role on that and the ability of a touchscreen to pick up a touch.
Walker, Geoff (August 2012). "A review of technologies for sensing contact location on the surface of a display: Review of touch technologies". Journal of the Society for Information Display. 20 (8): 413–440. doi:10.1002/jsid.100. S2CID 40545665.
"The first capacitative touch screens at CERN". CERN Courrier. 31 March 2010. Archived from the original on 4 September 2010. Retrieved 2010-05-25. Cite journal requires |journal= (help)
Johnson, E.A. (1965). "Touch Display - A novel input/output device for computers". Electronics Letters. 1 (8): 219–220. Bibcode:1965ElL.....1..219J. doi:10.1049/el:19650200.
Stumpe, Bent; Sutton, Christine (1 June 2010). "CERN touch screen". Symmetry Magazine. A joint Fermilab/SLAC publication. Archived from the original on 2016-11-16. Retrieved 16 November 2016.
Biferno, M. A., Stanley, D. L. (1983). The Touch-Sensitive Control/Display Unit: A Promising Computer Interface. Technical Paper 831532, Aerospace Congress & Exposition, Long Beach, CA: Society of Automotive Engineers.
Potter, R.; Weldon, L.; Shneiderman, B. (1988). "Improving the accuracy of touch screens: an experimental evaluation of three strategies". Proceedings of the SIGCHI conference on Human factors in computing systems - CHI "88. Proc. of the Conference on Human Factors in Computing Systems, CHI "88. Washington, DC. pp. 27–32. doi:10.1145/57167.57171. ISBN 0201142376. Archived from the original on 2015-12-08.
Sears, Andrew; Plaisant, Catherine; Shneiderman, Ben (June 1990). "A new era for high-precision touchscreens". In Hartson, R.; Hix, D. (eds.). Advances in Human-Computer Interaction. Vol. 3. Ablex (1992). ISBN 978-0-89391-751-7. Archived from the original on October 9, 2014.
Apple touch-screen patent war comes to the UK (2011). Event occurs at 1:24 min in video. Archived from the original on 8 December 2015. Retrieved 3 December 2015.
Hong, Chan-Hwa; Shin, Jae-Heon; Ju, Byeong-Kwon; Kim, Kyung-Hyun; Park, Nae-Man; Kim, Bo-Sul; Cheong, Woo-Seok (1 November 2013). "Index-Matched Indium Tin Oxide Electrodes for Capacitive Touch Screen Panel Applications". Journal of Nanoscience and Nanotechnology. 13 (11): 7756–7759. doi:10.1166/jnn.2013.7814. PMID 24245328. S2CID 24281861.
Kent, Joel (May 2010). "Touchscreen technology basics & a new development". CMOS Emerging Technologies Conference. CMOS Emerging Technologies Research. 6: 1–13. ISBN 9781927500057.
Ganapati, Priya (5 March 2010). "Finger Fail: Why Most Touchscreens Miss the Point". Archived from the original on 2014-05-11. Retrieved 9 November 2019.
Beyers, Tim (2008-02-13). "Innovation Series: Touchscreen Technology". The Motley Fool. Archived from the original on 2009-03-24. Retrieved 2009-03-16.
"Acoustic Pulse Recognition Touchscreens" (PDF). Elo Touch Systems. 2006: 3. Archived (PDF) from the original on 2011-09-05. Retrieved 2011-09-27. Cite journal requires |journal= (help)
Hoober, Steven (2013-11-11). "Design for Fingers and Thumbs Instead of Touch". UXmatters. Archived from the original on 2014-08-26. Retrieved 2014-08-24.
Henze, Niels; Rukzio, Enrico; Boll, Susanne (2011). "100,000,000 Taps: Analysis and Improvement of Touch Performance in the Large". Proceedings of the 13th International Conference on Human Computer Interaction with Mobile Devices and Services. New York.
Lee, Seungyons; Zhai, Shumin (2009). "The Performance of Touch Screen Soft Buttons". Proceedings of the SIGCHI Conference on Human Factors in Computing Systems. New York: 309. doi:10.1145/1518701.1518750. ISBN 9781605582467. S2CID 2468830.
Bérard, François (2012). "Measuring the Linear and Rotational User Precision in Touch Pointing". Proceedings of the 2012 ACM International Conference on Interactive Tabletops and Surfaces. New York: 183. doi:10.1145/2396636.2396664. ISBN 9781450312097. S2CID 15765730.
Hoober, Steven (2014-09-02). "Insights on Switching, Centering, and Gestures for Touchscreens". UXmatters. Archived from the original on 2014-09-06. Retrieved 2014-08-24.
Brasel, S. Adam; Gips, James (2014). "Tablets, touchscreens, and touchpads: How varying touch interfaces trigger psychological ownership and endowment". Journal of Consumer Psychology. 24 (2): 226–233. doi:10.1016/j.jcps.2013.10.003. S2CID 145501566.
Zhu, Ying; Meyer, Jeffrey (September 2017). "Getting in touch with your thinking style: How touchscreens influence purchase". Journal of Retailing and Consumer Services. 38: 51–58. doi:10.1016/j.jretconser.2017.05.006.
"A RESTAURANT THAT LETS GUESTS PLACE ORDERS VIA A TOUCHSCREEN TABLE (Touche is said to be the first touchscreen restaurant in India and fifth in the world)". India Business Insight. 31 August 2011. Gale A269135159.
Sears, A.; Plaisant, C. & Shneiderman, B. (1992). "A new era for high precision touchscreens". In Hartson, R. & Hix, D. (eds.). Advances in Human-Computer Interaction. Vol. 3. Ablex, NJ. pp. 1–33.
Sears, Andrew; Shneiderman, Ben (April 1991). "High precision touchscreens: design strategies and comparisons with a mouse". International Journal of Man-Machine Studies. 34 (4): 593–613. doi:10.1016/0020-7373(91)90037-8. hdl:
![]()
In computing, multi-touch is technology that enables a surface (a touchpad or touchscreen) to recognize the presence of more than one point of contact with the surface at the same time. The origins of multitouch began at CERN,MIT, University of Toronto, Carnegie Mellon University and Bell Labs in the 1970s.Super Proton Synchrotron.Apple"s iPhone in 2007.subroutines attached to predefined gestures.
Several uses of the term multi-touch resulted from the quick developments in this field, and many companies using the term to market older technology which is called
Multi-touch is commonly implemented using capacitive sensing technology in mobile devices and smart devices. A capacitive touchscreen typically consists of a capacitive touch sensor, application-specific integrated circuit (ASIC) controller and digital signal processor (DSP) fabricated from CMOS (complementary metal–oxide–semiconductor) technology. A more recent alternative approach is optical touch technology, based on image sensor technology.
Apple popularized the term "multi-touch" in 2007 with which it implemented additional functionality, such as pinch to zoom or to activate certain subroutines attached to predefined gestures.
The use of touchscreen technology predates both multi-touch technology and the personal computer. Early synthesizer and electronic instrument builders like Hugh Le Caine and Robert Moog experimented with using touch-sensitive capacitance sensors to control the sounds made by their instruments.IBM began building the first touch screens in the late 1960s. In 1972, Control Data released the PLATO IV computer, an infrared terminal used for educational purposes, which employed single-touch points in a 16×16 array user interface. These early touchscreens only registered one point of touch at a time. On-screen keyboards (a well-known feature today) were thus awkward to use, because key-rollover and holding down a shift key while typing another were not possible.
Exceptions to these were a "cross-wire" multi-touch reconfigurable touchscreen keyboard/display developed at the Massachusetts Institute of Technology in the early 1970s CERN in 1972 for the controls of the Super Proton Synchrotron that were under construction.
During the year 1976, a new x-y capacitive screen, based on the capacitance touch screens developed in 1972 by Danish electronics engineer Bent Stumpe, was developed at CERN.human machine interface (HMI) for the control room of the Super Proton Synchrotron particle accelerator.MIT described a keyboard with variable graphics capable of multi-touch detection.
In the early 1980s, The University of Toronto"s Input Research Group were among the earliest to explore the software side of multi-touch input systems.
In 1983, Bell Labs at Murray Hill published a comprehensive discussion of touch-screen based interfaces, though it makes no mention of multiple fingers.Myron Krueger was influential in development of multi-touch gestures such as pinch-to-zoom, though this system had no touch interaction itself.
By 1984, both Bell Labs and Carnegie Mellon University had working multi-touch-screen prototypes – both input and graphics – that could respond interactively in response to multiple finger inputs.Steve Jobs signed a non-disclosure agreement to tour CMU"s Sensor Frame multi-touch lab.human–computer interaction of the time, describing single touch gestures such as rotating knobs, swiping the screen to activate a switch (or a U-shaped gesture for a toggle switch), and touchscreen keyboards (including a study that showed that users could type at 25 words per minute for a touchscreen keyboard compared with 58 words per minute for a standard keyboard, with multi-touch hypothesized to improve data entry rate); multi-touch gestures such as selecting a range of a line, connecting objects, and a "tap-click" gesture to select while maintaining location with another finger are also described.
Between 1999 and 2005, the company Fingerworks developed various multi-touch technologies, including Touchstream keyboards and the iGesture Pad. in the early 2000s Alan Hedge, professor of human factors and ergonomics at Cornell University published several studies about this technology.
In 2004, french start-up JazzMutant developed the Lemur Input Device, a music controller that became in 2005 the first commercial product to feature a proprietary transparent multi-touch screen, allowing direct, ten-finger manipulation on the display.
In January 2007, multi-touch technology became mainstream with the iPhone, and in its iPhone announcement Apple even stated it "invented multi touch",
In 2001, Microsoft"s table-top touch platform, Microsoft PixelSense (formerly Surface) started development, which interacts with both the user"s touch and their electronic devices and became commercial on May 29, 2007. Similarly, in 2001, Mitsubishi Electric Research Laboratories (MERL) began development of a multi-touch, multi-user system called DiamondTouch.
In 2008, the Diamondtouch became a commercial product and is also based on capacitance, but able to differentiate between multiple simultaneous users or rather, the chairs in which each user is seated or the floorpad on which the user is standing.
Small-scale touch devices rapidly became commonplace in 2008. The number of touch screen telephones was expected to increase from 200,000 shipped in 2006 to 21 million in 2012.
Apple has retailed and distributed numerous products using multi-touch technology, most prominently including its iPhone smartphone and iPad tablet. Additionally, Apple also holds several patents related to the implementation of multi-touch in user interfaces,trademark in the United States—however its request was denied by the United States Patent and Trademark Office because it considered the term generic.
Multi-touch sensing and processing occurs via an ASIC sensor that is attached to the touch surface. Usually, separate companies make the ASIC and screen that combine into a touch screen; conversely, a touchpad"s surface and ASIC are usually manufactured by the same company. There have been large companies in recent years that have expanded into the growing multi-touch industry, with systems designed for everything from the casual user to multinational organizations.
It is now common for laptop manufacturers to include multi-touch touchpads on their laptops, and tablet computers respond to touch input rather than traditional stylus input and it is supported by many recent operating systems.
A few companies are focusing on large-scale surface computing rather than personal electronics, either large multi-touch tables or wall surfaces. These systems are generally used by government organizations, museums, and companies as a means of information or exhibit display. Large scale multi-touch surfaces are manufactured by Finnish company MultiTaction on their 55" MT Cells (55" screens) who also have office locations in London, California and Singapore. MultiTaction also build unique collaboration software especially designed for multi-touch screens such as MT Canvus and MT Showcase.
Multi-touch has been implemented in several different ways, depending on the size and type of interface. The most popular form are mobile devices, tablets, touchtables and walls. Both touchtables and touch walls project an image through acrylic or glass, and then back-light the image with LEDs.
Touch surfaces can also be made pressure-sensitive by the addition of a pressure-sensitive coating that flexes differently depending on how firmly it is pressed, altering the reflection.
Handheld technologies use a panel that carries an electrical charge. When a finger touches the screen, the touch disrupts the panel"s electrical field. The disruption is registered as a computer event (gesture) and may be sent to the software, which may then initiate a response to the gesture event.
In the past few years, several companies have released products that use multi-touch. In an attempt to make the expensive technology more accessible, hobbyists have also published methods of constructing DIY touchscreens.
Optical touch technology is based on image sensor technology. It functions when a finger or an object touches the surface, causing the light to scatter, the reflection of which is caught with sensors or cameras that send the data to software that dictates response to the touch, depending on the type of reflection measured.Rear Diffused Illumination (DI)
Multi-touch touchscreen gestures enable predefined motions to interact with the device and software. An increasing number of devices like smartphones, tablet computers, laptops or desktop computers have functions that are triggered by multi-touch gestures.
Years before it was a viable consumer product, popular culture portrayed potential uses of multi-touch technology in the future, including in several installments of the
In the 2005 film Sean Bean, has a multi-touch desktop to organize files, based on an early version of Microsoft Surfacetablet computers which now bear that name).
In a 2008, an episode of the television series Lisa Simpson travels to the underwater headquarters of Mapple to visit Steve Mobbs, who is shown to be performing multiple multi-touch hand gestures on a large touch wall.
Kent, Joel (May 2010). "Touchscreen technology basics & a new development". CMOS Emerging Technologies Conference. CMOS Emerging Technologies Research. 6: 1–13. ISBN 9781927500057.
Ganapati, Priya (5 March 2010). "Finger Fail: Why Most Touchscreens Miss the Point". Archived from the original on 11 May 2014. Retrieved 9 November 2019.
Henriksen, Benjamin; Munch Christensen, Jesper; Stumpe, Jonas (2012). The evolution of CERN"s capacitive touchscreen (PDF) (Bachelor). University of Copenhagen.
Stumpe, Bent; Sutton, Christine (1 June 2010). "CERN touch screen". Symmetry Magazine. A joint Fermilab/SLAC publication. Archived from the original on 16 November 2016. Retrieved 16 November 2016.
Lee, SK; Buxton, William; Smith, K. C. (1985-01-01). A Multi-touch Three Dimensional Touch-sensitive Tablet. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems. CHI "85. New York: ACM. pp. 21–25. doi:10.1145/317456.317461. ISBN 978-0897911498. S2CID 1196331.
Sears, A., Plaisant, C., Shneiderman, B. (June 1990) A new era for high-precision touchscreens. Advances in Human-Computer Interaction, vol. 3, Hartson, R. & Hix, D. Eds., Ablex (1992) 1-33 HCIL-90-01, CS-TR-2487, CAR-TR-506. [1]
Westerman, W., Elias J.G. and A.Hedge (2001) Multi-touch: a new tactile 2-d gesture interface for human-computer interaction Proceedings of the Human Factors and Ergonomics Society 45th Annual Meeting, Vol. 1, 632-636.
Shanis, J. and Hedge, A. (2003) Comparison of mouse, touchpad and multitouch input technologies. Proceedings of the Human Factors and Ergonomics Society 47th Annual Meeting, Oct. 13–17, Denver, CO, 746-750.
Thom-Santelli, J. and Hedge, A. (2005) Effects of a multitouch keyboard on wrist posture, typing performance and comfort. Proceedings of the Human Factors and Ergonomics Society 49th Annual Meeting, Orlando, Sept. 26-30, HFES, Santa Monica, 646-650.
Guillaume, Largillier. "Developing the First Commercial Product that Uses Multi-Touch Technology". informationdisplay.org/. SID Information Display Magazine. Retrieved 26 January 2018.
US 7724242, Hillis, W. Daniel & Ferren, Bran, "Touch driven method and apparatus to integrate and display multiple image layers forming alternate depictions of same subject matter", published May 25, 2010
Melanson, Donald (October 15, 2009). "10/GUI interface looks to redefine the touch-enabled desktop". Engadget. Archived from the original on 19 October 2009. Retrieved 2009-10-16.
![]()
Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is switched ON. Vertical ridges etched on the surface are smooth.
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directlybacklight or reflector to produce images in color or monochrome.seven-segment displays, as in a digital clock, are all good examples of devices with these displays. They use the same basic technology, except that arbitrary images are made from a matrix of small pixels, while other displays have larger elements. LCDs can either be normally on (positive) or off (negative), depending on the polarizer arrangement. For example, a character positive LCD with a backlight will have black lettering on a background that is the color of the backlight, and a character negative LCD will have a black background with the letters being of the same color as the backlight. Optical filters are added to white on blue LCDs to give them their characteristic appearance.
LCDs are used in a wide range of applications, including LCD televisions, computer monitors, instrument panels, aircraft cockpit displays, and indoor and outdoor signage. Small LCD screens are common in LCD projectors and portable consumer devices such as digital cameras, watches, calculators, and mobile telephones, including smartphones. LCD screens have replaced heavy, bulky and less energy-efficient cathode-ray tube (CRT) displays in nearly all applications. The phosphors used in CRTs make them vulnerable to image burn-in when a static image is displayed on a screen for a long time, e.g., the table frame for an airline flight schedule on an indoor sign. LCDs do not have this weakness, but are still susceptible to image persistence.
Each pixel of an LCD typically consists of a layer of molecules aligned between two transparent electrodes, often made of Indium-Tin oxide (ITO) and two polarizing filters (parallel and perpendicular polarizers), the axes of transmission of which are (in most of the cases) perpendicular to each other. Without the liquid crystal between the polarizing filters, light passing through the first filter would be blocked by the second (crossed) polarizer. Before an electric field is applied, the orientation of the liquid-crystal molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic (TN) device, the surface alignment directions at the two electrodes are perpendicular to each other, and so the molecules arrange themselves in a helical structure, or twist. This induces the rotation of the polarization of the incident light, and the device appears gray. If the applied voltage is large enough, the liquid crystal molecules in the center of the layer are almost completely untwisted and the polarization of the incident light is not rotated as it passes through the liquid crystal layer. This light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts thus constituting different levels of gray.
The chemical formula of the liquid crystals used in LCDs may vary. Formulas may be patented.Sharp Corporation. The patent that covered that specific mixture expired.
Most color LCD systems use the same technique, with color filters used to generate red, green, and blue subpixels. The LCD color filters are made with a photolithography process on large glass sheets that are later glued with other glass sheets containing a TFT array, spacers and liquid crystal, creating several color LCDs that are then cut from one another and laminated with polarizer sheets. Red, green, blue and black photoresists (resists) are used. All resists contain a finely ground powdered pigment, with particles being just 40 nanometers across. The black resist is the first to be applied; this will create a black grid (known in the industry as a black matrix) that will separate red, green and blue subpixels from one another, increasing contrast ratios and preventing light from leaking from one subpixel onto other surrounding subpixels.Super-twisted nematic LCD, where the variable twist between tighter-spaced plates causes a varying double refraction birefringence, thus changing the hue.
LCD in a Texas Instruments calculator with top polarizer removed from device and placed on top, such that the top and bottom polarizers are perpendicular. As a result, the colors are inverted.
The optical effect of a TN device in the voltage-on state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, TN displays with low information content and no backlighting are usually operated between crossed polarizers such that they appear bright with no voltage (the eye is much more sensitive to variations in the dark state than the bright state). As most of 2010-era LCDs are used in television sets, monitors and smartphones, they have high-resolution matrix arrays of pixels to display arbitrary images using backlighting with a dark background. When no image is displayed, different arrangements are used. For this purpose, TN LCDs are operated between parallel polarizers, whereas IPS LCDs feature crossed polarizers. In many applications IPS LCDs have replaced TN LCDs, particularly in smartphones. Both the liquid crystal material and the alignment layer material contain ionic compounds. If an electric field of one particular polarity is applied for a long period of time, this ionic material is attracted to the surfaces and degrades the device performance. This is avoided either by applying an alternating current or by reversing the polarity of the electric field as the device is addressed (the response of the liquid crystal layer is identical, regardless of the polarity of the applied field).
Displays for a small number of individual digits or fixed symbols (as in digital watches and pocket calculators) can be implemented with independent electrodes for each segment.alphanumeric or variable graphics displays are usually implemented with pixels arranged as a matrix consisting of electrically connected rows on one side of the LC layer and columns on the other side, which makes it possible to address each pixel at the intersections. The general method of matrix addressing consists of sequentially addressing one side of the matrix, for example by selecting the rows one-by-one and applying the picture information on the other side at the columns row-by-row. For details on the various matrix addressing schemes see passive-matrix and active-matrix addressed LCDs.
LCDs are manufactured in cleanrooms borrowing techniques from semiconductor manufacturing and using large sheets of glass whose size has increased over time. Several displays are manufactured at the same time, and then cut from the sheet of glass, also known as the mother glass or LCD glass substrate. The increase in size allows more displays or larger displays to be made, just like with increasing wafer sizes in semiconductor manufacturing. The glass sizes are as follows:
Until Gen 8, manufacturers would not agree on a single mother glass size and as a result, different manufacturers would use slightly different glass sizes for the same generation. Some manufacturers have adopted Gen 8.6 mother glass sheets which are only slightly larger than Gen 8.5, allowing for more 50 and 58 inch LCDs to be made per mother glass, specially 58 inch LCDs, in which case 6 can be produced on a Gen 8.6 mother glass vs only 3 on a Gen 8.5 mother glass, significantly reducing waste.AGC Inc., Corning Inc., and Nippon Electric Glass.
The origins and the complex history of liquid-crystal displays from the perspective of an insider during the early days were described by Joseph A. Castellano in Liquid Gold: The Story of Liquid Crystal Displays and the Creation of an Industry.IEEE History Center.Peter J. Wild, can be found at the Engineering and Technology History Wiki.
In 1922, Georges Friedel described the structure and properties of liquid crystals and classified them in three types (nematics, smectics and cholesterics). In 1927, Vsevolod Frederiks devised the electrically switched light valve, called the Fréedericksz transition, the essential effect of all LCD technology. In 1936, the Marconi Wireless Telegraph company patented the first practical application of the technology, "The Liquid Crystal Light Valve". In 1962, the first major English language publication Molecular Structure and Properties of Liquid Crystals was published by Dr. George W. Gray.RCA found that liquid crystals had some interesting electro-optic characteristics and he realized an electro-optical effect by generating stripe-patterns in a thin layer of liquid crystal material by the application of a voltage. This effect is based on an electro-hydrodynamic instability forming what are now called "Williams domains" inside the liquid crystal.
In 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 r
Ms.Josey
Ms.Josey