a si active matrix tft lcd factory

The most common semiconducting layer is made of amorphous silicon (a-Si). a-Si  thin film transistor - liquid crystal display (TFT-LCD) has been the dominant technology for the manufacturing of active matrix TFT-LCD for over 20 years. a-Si is a low cost material in abundant supply.

a-Si is a low cost material in abundant supply. However, the electron mobility of a-Si is very low (around 1cm2/Vs) and can’t physically support high refresh rates such as the 240Hz needed for HDTV. Due to their high electron mobility, new materials such as metal oxide (MO) and low temperature polysilicon (LTPS) are now replacing a-Si to manufacture the industry’s two main types of screens: LCD and organic light-emitting diode (OLED) displays.

Microtech Technology Company Limitedestablished in 2001,offers professional design and manufacturing services for hundreds types of Liquid Crytal Display modules and Touch Panels-TN,FSTN,TFT,RTP,CTP.With the advantages of high contrast,fast response time,wide viewable angle and low power consumption,Microtech"s products are widely used in Industrial Equipment,Medical devices,Home Intelligent Devices,Digital cameras,Video Game Devices,Instruments etc.Since its establishment,the management has been following human-oriented strategy and developing reliance among customers.To comply with these beliefs and ISO 9001:2015 standards,Microtech keeps on recruiting capable professionals,adopting advanced technology,developing new products,improving process and enhancing quality.Based on its strong R&D capacity, outstanding product quality and professional service,Microtech has won the high reputation from both mainland and oversea customers,and established long-term strategic partner relationship with them.

Our products are not only satisfy the display individuation requirement of all the mobile phone manufacturing factories in the mainland,but also meet the highly uniformity and reliability requirement to the display effect of module for many famous brands in Europe,American and Asia pacific.In addition,our products which have reached the extent of excellent quality and reliability could be applied in Automotive,Medical,Power station,Transportation,Industrial & Equipment and Office equipment for many famous enterprises in American,France,Italy,Australia,Korea and so on.

Our company have passed theISO 9001 quality system certification and SGS, RoHS, CE certification, to ensure all of our products and services are in international standard.

In order to obtain an excellent quality management team and offer our customers professional & efficient service and satisfied products,We comprehensively carry out Zero Defect quality management,implement ISO9001:2008 standards training and organize the examination /enrollment of quality management personnel national professional qualification.Our Mission "Efficient and timely service is the key to our success.Our success is tied with our client"s success. We are dedicated to provide excellent service to our customer at the most competitive prices." To provide customer a value added LCD product by stringent quality control,comprehensive technical support,and utilization of latest technology.

With our motto "Quality and Services are vital to enterpriess",Microtech aims to produce high quality LCD module to meet the customers" specific needs in all-round way.Meanwhile we seek for continuous service improvement,increase our market share,strengthen our competitiveness,and ultimately,expand our market worldwide!

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* Product descriptions and part numbers are subject to change, and may not reflect manufacturer product changes. Please check the manufacturer"s website and use the item"s manufacturer part number to find the most up to date product description.

Offering you a complete choice of products which include Si TFT Active Matrix LCD, 3.5" Active Matrix LCD Panel, 7" Amorphous Transmissive Tft LCD Screen, 6.7" Amorphous Si TFT Color LCD Module, PQ 3Qi-01 is a 10.1" TFT Liquid Crystal Display and TFT LCD Panel 3.45.

A si TFT active matrix LCD of 7"(diagonal dimensions) with a resolution of 800*3(RGB)*480. Features include white LED backlight and VGA and Video input.The signal interface is parallel RGB(1ch,6-bit) with wide range of display colors of 262K.

It features Transmissive type and back-light with six LEDS(Serial type) with support resolution of n 320xRGBx240 (16.7M Color) which includes 24bit parallel RGB Interface (8bit x 3).

A070VW04_V1 is an amorphous transmissive type TFT (Thin Film Transistor) LCD (Liquid crystal Display). This model is composed of TFT-LCD, driver IC, FPC (flexible printed circuit), and backlight unit.

This color LCD module is composed of amorphous silicon thin film transistor liquid crystal display panel structure with driver LSis for driving the TFT array and a backlight.Color (Red,Green,Blue) data signals from a host system e.g. signal generator are modulated into the best form for active matrix system by signal processing board, and sent to the driver LSIs which drive the individual TFT arrays.

This 10.1” TFT Liquid Crystal Display module supports 1024 x RGB x 600 Wide-SVGA (WSVGA) mode and can display 262,144 colors.This module also supports two low power modes: a transflective mode with lower color and a reflective black and white (64 grayscales) mode. In reflective mode the screens shows higher resolution at 3072 x 600 pixels, in transflective mode the color resolution is 1024 x RGB x 600, while the black/white/grey resolution is 3072 x 600. The converter module for the LED backlight is built in.

3.45“ color TFT-LCD panel. The 3.45“ color TFT-LCD panel is designed for camcorder, digital camera application and other electronic products which require high quality flat panel displays. This module follows RoHS.Added features include High Resolution :230,400 Dots (320 RGB x 240) . Image Reversion: Up/Down and Left/Right.

A thin-film-transistor liquid-crystal display (TFT LCD) is a variant of a liquid-crystal display that uses thin-film-transistor technologyactive matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven (i.e. with segments directly connected to electronics outside the LCD) LCDs with a few segments.

In February 1957, John Wallmark of RCA filed a patent for a thin film MOSFET. 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. The idea of a TFT-based liquid-crystal display (LCD) was conceived by Bernard Lechner of RCA Laboratories in 1968. In 1971, Lechner, F. J. Marlowe, E. O. Nester and J. Tults demonstrated a 2-by-18 matrix display driven by a hybrid circuit using the dynamic scattering mode of LCDs.T. Peter Brody, J. A. Asars and G. D. Dixon at Westinghouse Research Laboratories developed a CdSe (cadmium selenide) TFT, which they used to demonstrate the first CdSe thin-film-transistor liquid-crystal display (TFT LCD).active-matrix liquid-crystal display (AM LCD) using CdSe TFTs in 1974, and then Brody coined the term "active matrix" in 1975.high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays.

The liquid crystal displays used in calculators and other devices with similarly simple displays have direct-driven image elements, and therefore a voltage can be easily applied across just one segment of these types of displays without interfering with the other segments. This would be impractical for a large display, because it would have a large number of (color) picture elements (pixels), and thus it would require millions of connections, both top and bottom for each one of the three colors (red, green and blue) of every pixel. To avoid this issue, the pixels are addressed in rows and columns, reducing the connection count from millions down to thousands. The column and row wires attach to transistor switches, one for each pixel. The one-way current passing characteristic of the transistor prevents the charge that is being applied to each pixel from being drained between refreshes to a display"s image. Each pixel is a small capacitor with a layer of insulating liquid crystal sandwiched between transparent conductive ITO layers.

The circuit layout process of a TFT-LCD is very similar to that of semiconductor products. However, rather than fabricating the transistors from silicon, that is formed into a crystalline silicon wafer, they are made from a thin film of amorphous silicon that is deposited on a glass panel. The silicon layer for TFT-LCDs is typically deposited using the PECVD process.

Polycrystalline silicon is sometimes used in displays requiring higher TFT performance. Examples include small high-resolution displays such as those found in projectors or viewfinders. Amorphous silicon-based TFTs are by far the most common, due to their lower production cost, whereas polycrystalline silicon TFTs are more costly and much more difficult to produce.

The twisted nematic display is one of the oldest and frequently cheapest kind of LCD display technologies available. TN displays benefit from fast pixel response times and less smearing than other LCD display technology, but suffer from poor color reproduction and limited viewing angles, especially in the vertical direction. Colors will shift, potentially to the point of completely inverting, when viewed at an angle that is not perpendicular to the display. Modern, high end consumer products have developed methods to overcome the technology"s shortcomings, such as RTC (Response Time Compensation / Overdrive) technologies. Modern TN displays can look significantly better than older TN displays from decades earlier, but overall TN has inferior viewing angles and poor color in comparison to other technology.

Most TN panels can represent colors using only six bits per RGB channel, or 18 bit in total, and are unable to display the 16.7 million color shades (24-bit truecolor) that are available using 24-bit color. Instead, these panels display interpolated 24-bit color using a dithering method that combines adjacent pixels to simulate the desired shade. They can also use a form of temporal dithering called Frame Rate Control (FRC), which cycles between different shades with each new frame to simulate an intermediate shade. Such 18 bit panels with dithering are sometimes advertised as having "16.2 million colors". These color simulation methods are noticeable to many people and highly bothersome to some.gamut (often referred to as a percentage of the NTSC 1953 color gamut) are also due to backlighting technology. It is not uncommon for older displays to range from 10% to 26% of the NTSC color gamut, whereas other kind of displays, utilizing more complicated CCFL or LED phosphor formulations or RGB LED backlights, may extend past 100% of the NTSC color gamut, a difference quite perceivable by the human eye.

The transmittance of a pixel of an LCD panel typically does not change linearly with the applied voltage,sRGB standard for computer monitors requires a specific nonlinear dependence of the amount of emitted light as a function of the RGB value.

In-plane switching was developed by Hitachi Ltd. in 1996 to improve on the poor viewing angle and the poor color reproduction of TN panels at that time.

Initial iterations of IPS technology were characterised by slow response time and a low contrast ratio but later revisions have made marked improvements to these shortcomings. Because of its wide viewing angle and accurate color reproduction (with almost no off-angle color shift), IPS is widely employed in high-end monitors aimed at professional graphic artists, although with the recent fall in price it has been seen in the mainstream market as well. IPS technology was sold to Panasonic by Hitachi.

Most panels also support true 8-bit per channel color. These improvements came at the cost of a higher response time, initially about 50 ms. IPS panels were also extremely expensive.

IPS has since been superseded by S-IPS (Super-IPS, Hitachi Ltd. in 1998), which has all the benefits of IPS technology with the addition of improved pixel refresh timing.

In 2004, Hydis Technologies Co., Ltd licensed its AFFS patent to Japan"s Hitachi Displays. Hitachi is using AFFS to manufacture high end panels in their product line. In 2006, Hydis also licensed its AFFS to Sanyo Epson Imaging Devices Corporation.

It achieved pixel response which was fast for its time, wide viewing angles, and high contrast at the cost of brightness and color reproduction.Response Time Compensation) technologies.

Less expensive PVA panels often use dithering and FRC, whereas super-PVA (S-PVA) panels all use at least 8 bits per color component and do not use color simulation methods.BRAVIA LCD TVs offer 10-bit and xvYCC color support, for example, the Bravia X4500 series. S-PVA also offers fast response times using modern RTC technologies.

When the field is on, the liquid crystal molecules start to tilt towards the center of the sub-pixels because of the electric field; as a result, a continuous pinwheel alignment (CPA) is formed; the azimuthal angle rotates 360 degrees continuously resulting in an excellent viewing angle. The ASV mode is also called CPA mode.

A technology developed by Samsung is Super PLS, which bears similarities to IPS panels, has wider viewing angles, better image quality, increased brightness, and lower production costs. PLS technology debuted in the PC display market with the release of the Samsung S27A850 and S24A850 monitors in September 2011.

TFT dual-transistor pixel or cell technology is a reflective-display technology for use in very-low-power-consumption applications such as electronic shelf labels (ESL), digital watches, or metering. DTP involves adding a secondary transistor gate in the single TFT cell to maintain the display of a pixel during a period of 1s without loss of image or without degrading the TFT transistors over time. By slowing the refresh rate of the standard frequency from 60 Hz to 1 Hz, DTP claims to increase the power efficiency by multiple orders of magnitude.

Due to the very high cost of building TFT factories, there are few major OEM panel vendors for large display panels. The glass panel suppliers are as follows:

External consumer display devices like a TFT LCD feature one or more analog VGA, DVI, HDMI, or DisplayPort interface, with many featuring a selection of these interfaces. Inside external display devices there is a controller board that will convert the video signal using color mapping and image scaling usually employing the discrete cosine transform (DCT) in order to convert any video source like CVBS, VGA, DVI, HDMI, etc. into digital RGB at the native resolution of the display panel. In a laptop the graphics chip will directly produce a signal suitable for connection to the built-in TFT display. A control mechanism for the backlight is usually included on the same controller board.

The low level interface of STN, DSTN, or TFT display panels use either single ended TTL 5 V signal for older displays or TTL 3.3 V for slightly newer displays that transmits the pixel clock, horizontal sync, vertical sync, digital red, digital green, digital blue in parallel. Some models (for example the AT070TN92) also feature input/display enable, horizontal scan direction and vertical scan direction signals.

New and large (>15") TFT displays often use LVDS signaling that transmits the same contents as the parallel interface (Hsync, Vsync, RGB) but will put control and RGB bits into a number of serial transmission lines synchronized to a clock whose rate is equal to the pixel rate. LVDS transmits seven bits per clock per data line, with six bits being data and one bit used to signal if the other six bits need to be inverted in order to maintain DC balance. Low-cost TFT displays often have three data lines and therefore only directly support 18 bits per pixel. Upscale displays have four or five data lines to support 24 bits per pixel (truecolor) or 30 bits per pixel respectively. Panel manufacturers are slowly replacing LVDS with Internal DisplayPort and Embedded DisplayPort, which allow sixfold reduction of the number of differential pairs.

Backlight intensity is usually controlled by varying a few volts DC, or generating a PWM signal, or adjusting a potentiometer or simply fixed. This in turn controls a high-voltage (1.3 kV) DC-AC inverter or a matrix of LEDs. The method to control the intensity of LED is to pulse them with PWM which can be source of harmonic flicker.

The bare display panel will only accept a digital video signal at the resolution determined by the panel pixel matrix designed at manufacture. Some screen panels will ignore the LSB bits of the color information to present a consistent interface (8 bit -> 6 bit/color x3).

With analogue signals like VGA, the display controller also needs to perform a high speed analog to digital conversion. With digital input signals like DVI or HDMI some simple reordering of the bits is needed before feeding it to the rescaler if the input resolution doesn"t match the display panel resolution.

The statements are applicable to Merck KGaA as well as its competitors JNC Corporation (formerly Chisso Corporation) and DIC (formerly Dainippon Ink & Chemicals). All three manufacturers have agreed not to introduce any acutely toxic or mutagenic liquid crystals to the market. They cover more than 90 percent of the global liquid crystal market. The remaining market share of liquid crystals, produced primarily in China, consists of older, patent-free substances from the three leading world producers and have already been tested for toxicity by them. As a result, they can also be considered non-toxic.

Kawamoto, H. (2012). "The Inventors of TFT Active-Matrix LCD Receive the 2011 IEEE Nishizawa Medal". Journal of Display Technology. 8 (1): 3–4. Bibcode:2012JDisT...8....3K. doi:10.1109/JDT.2011.2177740. ISSN 1551-319X.

Brody, T. Peter; Asars, J. A.; Dixon, G. D. (November 1973). "A 6 × 6 inch 20 lines-per-inch liquid-crystal display panel". 20 (11): 995–1001. Bibcode:1973ITED...20..995B. doi:10.1109/T-ED.1973.17780. ISSN 0018-9383.

Richard Ahrons (2012). "Industrial Research in Microcircuitry at RCA: The Early Years, 1953–1963". 12 (1). IEEE Annals of the History of Computing: 60–73. Cite journal requires |journal= (help)

K. H. Lee; H. Y. Kim; K. H. Park; S. J. Jang; I. C. Park & J. Y. Lee (June 2006). "A Novel Outdoor Readability of Portable TFT-LCD with AFFS Technology". SID Symposium Digest of Technical Papers. AIP. 37 (1): 1079–82. doi:10.1889/1.2433159. S2CID 129569963.

Kim, Sae-Bom; Kim, Woong-Ki; Chounlamany, Vanseng; Seo, Jaehwan; Yoo, Jisu; Jo, Hun-Je; Jung, Jinho (15 August 2012). "Identification of multi-level toxicity of liquid crystal display wastewater toward Daphnia magna and Moina macrocopa". Journal of Hazardous Materials. Seoul, Korea; Laos, Lao. 227–228: 327–333. doi:10.1016/j.jhazmat.2012.05.059. PMID 22677053.

If you want to buy a new monitor, you might wonder what kind of display technologies I should choose. In today’s market, there are two main types of computer monitors: TFT LCD monitors & IPS monitors.

The word TFT means Thin Film Transistor. It is the technology that is used in LCD displays.  We have additional resources if you would like to learn more about what is a TFT Display. This type of LCDs is also categorically referred to as an active-matrix LCD.

These LCDs can hold back some pixels while using other pixels so the LCD screen will be using a very minimum amount of energy to function (to modify the liquid crystal molecules between two electrodes). TFT LCDs have capacitors and transistors. These two elements play a key part in ensuring that the TFT display monitor functions by using a very small amount of energy while still generating vibrant, consistent images.

Industry nomenclature: TFT LCD panels or TFT screens can also be referred to as TN (Twisted Nematic) Type TFT displays or TN panels, or TN screen technology.

IPS (in-plane-switching) technology is like an improvement on the traditional TFT LCD display module in the sense that it has the same basic structure, but has more enhanced features and more widespread usability.

These LCD screens offer vibrant color, high contrast, and clear images at wide viewing angles. At a premium price. This technology is often used in high definition screens such as in gaming or entertainment.

Both TFT display and IPS display are active-matrix displays, neither can’t emit light on their own like OLED displays and have to be used with a back-light of white bright light to generate the picture. Newer panels utilize LED backlight (light-emitting diodes) to generate their light hence utilizing less power and requiring less depth by design. Neither TFT display nor IPS display can produce color, there is a layer of RGB (red, green, blue) color filter in each LCD pixels to produce the color consumers see. If you use a magnifier to inspect your monitor, you will see RGB color in each pixel. With an on/off switch and different level of brightness RGB, we can get many colors.

Wider viewing angles are not always welcome or needed. Image you work on the airplane. The person sitting next to you always looking at your screen, it can be very uncomfortable. There are more expensive technologies to narrow the viewing angle on purpose to protect the privacy.

Winner. IPS TFT screens have around 0.3 milliseconds response time while TN TFT screens responds around 10 milliseconds which makes the latter unsuitable for gaming

Winner. the images that IPS displays create are much more pristine and original than that of the TFT screen. IPS displays do this by making the pixels function in a parallel way. Because of such placing, the pixels can reflect light in a better way, and because of that, you get a better image within the display.

As the display screen made with IPS technology is mostly wide-set, it ensures that the aspect ratio of the screen would be wider. This ensures better visibility and a more realistic viewing experience with a stable effect.

Winner. While the TFT LCD has around 15% more power consumption vs IPS LCD, IPS has a lower transmittance which forces IPS displays to consume more power via backlights. TFT LCD helps battery life.

Normally, high-end products, such as Apple Mac computer monitors and Samsung mobile phones, generally use IPS panels. Some high-end TV and mobile phones even use AMOLED (Active Matrix Organic Light Emitting Diodes) displays. This cutting edge technology provides even better color reproduction, clear image quality, better color gamut, less power consumption when compared to LCD technology.

What you need to choose is AMOLED for your TV and mobile phones instead of PMOLED. If you have budget leftover, you can also add touch screen functionality as most of the touch nowadays uses PCAP (Projective Capacitive) touch panel.

This kind of touch technology was first introduced by Steve Jobs in the first-generation iPhone. Of course, a TFT LCD display can always meet the basic needs at the most efficient price. An IPS display can make your monitor standing out.

The liquid crystal research of the 1960s was characterized by the discovery of and experiments on the properties of the liquid crystals. George H. Heilmeier of the RCA based his research on that of Williams, diving into the electro-optical nature of the crystals. After many attempts to use the liquid crystals to display different colors, he created the first working LCD using something called a dynamic scattering mode (DSM) that, when voltage is applied, turns the clear liquid crystal layer into a more translucent state. Heilmeier was thus deemed the inventor of the LCD.

In the late 1960s, the United Kingdom Royal Radar Establishment (RRE) discovered the cyanobiphenyl liquid crystal, a type that was fitting for LCD usage in terms of stability and temperature. In 1968, Bernard Lechner of RCA created the idea of a TFT-based LCD, and in that same year, he and several others brought that idea into reality using Heilmeier’s DSM LCD.

After the LCD’s entrance into the field of display technology, the 1970s were full of expansive research into improving the LCD and making it appropriate for a greater variety of applications. In 1970, the twisted nematic field effect was patented in Switzerland with credited inventors being Wolfgang Helfrich and Martin Schadt. This twisted nematic (TN) effect soon conjoined with products that entered the international markets like Japan’s electronic industry. In the US, the same patent was filed by James Fergason in 1971. His company, ILIXCO, known today as LXD Incorporated, manufactured TN-effect LCDs which grew to overshadow the DSM models. TN LCDs offered better features like lower operating voltages and power consumption.

From this, the first digital clock, or more specifically an electronic quartz wristwatch, using a TN-LCD and consisting of four digits was patented in the US and released to consumers in 1972. Japan’s Sharp Corporation, in 1975, began mass production of digital watch and pocket calculator TN LCDs, and eventually, other Japanese corporations began to rise in the market for wristwatch displays. Seiko, as an example, developed the first six-digit TN-based LCD quartz watch, an upgrade from the original four-digit watch.

Nevertheless, the DSM LCD was not rendered completely useless. A 1972 development by the North American Rockwell Microelectronics Corp integrated the DSM LCD into calculators marketed by Lloyds Electronics. These required a form of internal light to show the display, and so backlightswere also incorporated into these calculators. Shortly after, in 1973, Sharp Corporation brought DSM LCD pocket-sized calculators into the picture. A polymer called polyimide was used as the orientation layer of liquid crystal molecules.

In the 1980s, there was rapid progress made in creating usable products with this new LCD research. Color LCD television screens were first developed in Japan during this decade. Because of the limit in response times due to large display size (correlated with a large number of pixels), the first TVs were handheld/pocket TVs. Seiko Epson, or Epson, created the first LCD TV, releasing it to the public in 1982, which was soon followed by their first fully colored display pocket LCD TV in 1984. Also in 1984 was the first commercial TFT LCD display: Citizen Watch’s 2.7 inch color LCD TV. Shortly after, in 1988, Sharp Corporation created a 14 inch full-color TFT LCD that used an active matrix and had full-motion properties. Large-size LCDs now made LCD integration into large flat-panel displays like LCD screens and LCD monitors possible. LCD projection technology, first created by Epson, became readily available to consumers in compact and fully colored modes in 1989.

The LCD growth in the 1990s focused more on the optical properties of these new displays in attempts to advance their quality and abilities. Hitachi engineers were integral to the analysis of the LCD industry, previously centered in Japan, began expanding and moving towards South Korea, Taiwan, and later China as well.

As we entered the new century, the prominence of LCDs boomed. They surpassed the previously popular cathode-ray tube (CRT) displays in both image quality and sales across the world in 2007. Other developments continued to be made, such as the manufacturing of even larger displays, adoption of transparent and flexible materials for LCD hardware, and creation of more methods to

As of today, as LCD displays have developed quite a bit, but have remained consistent in structure. Illuminated by a backlight, the display consists of, from outermost to innermost two polarizers, two substrates (typically glass), electrodes, and the liquid crystal layer. Closer to the surface is sometimes a color filter as well, using an RGB scheme. As light passes through the polarizer closest to the backlight, it enters the liquid crystal layer. Now, depending on whether an electric field directed by the electrodes is present, the liquid crystal will behave differently. Whether using a TN, IPS, or MVS LCD, the electrode electric field will alter the orientation of the liquid crystal molecules to then affect the polarization of the passing light. If the light is polarized properly, it will pass completely through the color filter and surface polarizer, displaying a certain color. If partially polarized correctly, it will display a medium level of light, or a less bright color. If not polarized properly, the light will not pass the surface, and no color will be displayed.

1927: Vsevolod Frederiks in Russian devised the electrically switched light valve, called the Fréedericksz transition, the essential effect of all LCD technology.

1967: Bernard Lechner, Frank Marlowe, Edward Nester and Juri Tults built the first LCD to operate at television rates using discrete MOS transistors wired to the device.

1968: A research group at RCA laboratories in the US, headed by George Heilmeier, developed the first LCDs based on DSM (dynamic scattering mode) and the first bistable LCD using a mixture of cholesteric and nematic liquid crystals. The result sparked a worldwide effort to further develop LCDs. 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.

1969: James Fergason, an associate director of Liquid Crystal Institute at Kent State University in Ohio, discovered the TN (twisted nematic) field effect.

1979, Peter Le Comber and Walter Spear at University of Dundee discovered that hydrogenated amorphous silicon (Alpha-Si:H) thin film transistors were suitable to drive LCDs. This is the major breakthrough that led to LCD television and computer displays.

1972: Tadashi Sasaki and Tomio Wada at Sharp Corporation built a prototype desktop calculator with a dynamic scattering LCD and started a program to build the first truly portable handheld calculator.

AMOLED is a product differentiator featuring the deepest blacks and most vibrant colors. However, conventional AMOLED manufacturing requires a complex, expensive backplane to drive the emissive OLED frontplane.

Large thin-film transistor liquid crystal display (TFT LCD) panel makers are expected to reduce production of comparatively smaller sized 32-, 40- and 43-inch panels, helping to stabilize panel prices in the third quarter of 2018. In the longer term, however, the oversupply issue still remains, eventually causing older TFT LCD fabs to be restructured, according to IHS Markit (Nasdaq: INFO).

According to the latest AMOLED and LCD Supply Demand & Equipment Tracker by IHS Markit, currently planned new factories will increase large display panel production capacity by 31 percent or 77.7M square meters from 2018 to 2021. However, based on the current demand forecast, there will be about 49 million square meters of capacity in the pipeline more than the market requires in 2021. The supply/demand glut level is expected to continue to increase from 12 percent in 2018 to 23 percent in 2021, remaining well above 10 percent or what is modeled to be a balanced market.

Between 2019 and 2021, there will be a great amount of LCD TV panel capacity built, mainly from generation Gen10.5/11 factories in China, according to IHS Markit.

“Some panel makers may be forced to reduce utilization rates, while some planned capacity may never be built,” said David Hsieh, senior director of displays at IHS Markit. “Furthermore, in the next few years, legacy factory restructuring will likely accelerate. For the TFT LCD industry to return to a balanced supply/demand level, multiple Gen 5, Gen 6 and even Gen 8 factories will likely need to be shut down.”

For example, shutting down half of all Gen 5 and Gen 6 amorphous silicon (a-Si) capacity in Taiwan would remove about 18 million square meters of production capacity, according to IHS Markit. Larger glass substrate capacity, such as Gen 8, will also likely need to be closed to bring the market back toward balance.

Possible restructuring of legacy factories may include fab shutdown, facility consolidation, or conversion to other technologies, such as active-matrix organic light-emitting diode (AMOLED) panels, ePaper backplanes and sensors.

According to the Display Production & Inventory Tracker by IHS Markit, fab restructuring can be attributed to multiple reasons, such as no longer competitive, old equipment, shifts in panel makers’ business focus, excessive overhead from under-utilized facilities and pressure on profitability.

“Oversupply is not the end of the crystal cycle. The industry has a long history of dynamically adjusting itself to balance supply and demand,” Hsieh said. “The process may create many challenges for supply chain companies. However, the delayed expansion of new factories, the restructuring of legacy fabs and the potential for faster demand growth spurred by lower panel prices will help the LCD industry to eventually return to equilibrium.”

TFT (Thin-Film Transistor) Displays are active-matrix LCDs with full RGB color screens. These screens feature bright, vivid colors and have the ability to show fast animations, complex graphics and crisp custom fonts. TFTs are perfect displays for providing a rich user interface for all types of products. While typically used in consumer devices like personal DVD players and handheld devices, TFTs are also well suited for industrial application.

TFTs are Active-Matrix LCDs that have tiny switching transistors and capacitors. These tiny transistors control each pixel on the display and require very little energy to actively change the orientation of the liquid crystal in the display. This allows for faster control of each Red, Green and Blue sub-pixel cell thus producing clear fast-moving color graphics.

The transistors in the TFT are arranged in a matrix on the glass substrate. Each pixel on the display remains off until addressed by applying a charge to the transistor. Unlike conventional Passive-Matrix displays, in order to activate a specific pixel, the corresponding row is turned on and a charge is sent down the proper column. This is where only the capacitor at the designated pixel receives a charge and is held until the next refresh cycle. Essentially, each transistor acts as an active switch. By incorporating an active switch, this limits the number of scan lines and eliminates cross-talk issues.

The main problem with TN Film technology is that viewing angles are pretty restrictive, especially vertically, and this is evident by a characteristic severe darkening of the image if you look at the screen from below. Contrast and colour tone shifts can be evident with even a slight movement off-centre, and this is perhaps the main drawback in modern TN Film panels. Some TN Film panels are better than others and there have been improvements over the years to some degree, but they are still far more restrictive with fields of view than other panel technologies.

MVA (Multi-domain Vertical Alignment) displays can offer wide viewing angles, good black depth, fast response times, and good color reproduction and depth. Each pixel within a MVA type TFT consists of three sub-pixels (Red, Green and Blue). Each of these sub-pixels is divided further into two or more sub-pixels, where the liquid crystals are randomly lined up due to the ridged polarized glass. When a charge is applied to the transistor, the crystals twist. With these crystals being randomly placed, it allows the backlight to shine through in all different directions keeping the intended color saturation retained while giving the display a 150deg. viewing angle.

In-Plane Switching (IPS) TFTs were developed to improve on the poor viewing angle and the poor color reproduction of TN TFT panels at that time. The crystal molecules move parallel to the panel plane instead of perpendicular to it. This change reduces the amount of light scattering in the matrix, which gives IPS its characteristic wide viewing angles and good color reproduction. Because of its wide viewing angle and accurate color reproduction (with almost no off-angle color shift), IPS is widely employed in high-end monitors aimed at professional graphic artists.

The name In-Plane Switching comes from the crystals in the cells of the IPS panel lying always in the same plane and being always parallel to the panel’s plane (if we don’t take into account the minor interference from the electrodes). When voltage is applied to a cell, the crystals of that cell all make a 90-degrees turn. By the way, an IPS panel lets the backlight pass through in its active state and shutters it in its passive state (when no voltage is applied), so if a thin-film transistor crashes, the corresponding pixel will always remain black, unlike with TN matrices.

IPS (In-Plane Switching) displays provide consistent, accurate color from all viewing angles without blur or grayscale inversion. IPS displays show clear images with fast response time, and no halo effect is produced when touched. Each pixel within an IPS type TFT consists of three sub-pixels (Red, Green and Blue). Each sub-pixel has a pair of electrodes to control the twisting of the Liquid Crystals. Unlike TN type TFTs where the electrodes are on opposing plates, the electrodes in an IPS TFT are on only one of the glass plates (i.e. in the same plane). When voltage is applied to the electrodes, all the Liquid Crystal molecules align in parallel with that plane and allow light to pass through to the polarizers and RGB color filters. In effect, TN displays force the Liquid Crystal molecules perpendicular to the glass which blocks some light from coming out at wide angles, while IPS displays keep the Liquid Crystal molecules in line to allow light through at all angles.

Low-temperature polycrystalline silicon (LTPS) is polycrystalline silicon that has been synthesized at relatively low temperatures (~650 °C and lower) compared to in traditional methods (above 900 °C). LTPS is important for display industries, since the use of large glass panels prohibits exposure to deformative high temperatures. More specifically, the use of polycrystalline silicon in thin-film transistors (LTPS-TFT) has high potential for large-scale production of electronic devices like flat panel LCD displays or image sensors.

Polycrystalline silicon (p-Si) is a pure and conductive form of the element composed of many crystallites, or grains of highly ordered crystal lattice. In 1984, studies showed that amorphous silicon (a-Si) is an excellent precursor for forming p-Si films with stable structures and low surface roughness. Silicon film is synthesized by low-pressure chemical vapor deposition (LPCVD) to minimize surface roughness. First, amorphous silicon is deposited at 560–640 °C. Then it is thermally annealed (recrystallized) at 950–1000 °C. Starting with the amorphous film, rather than directly depositing crystals, produces a product with a superior structure and a desired smoothness. In 1988, researchers discovered that further lowering temperature during annealing, together with advanced plasma-enhanced chemical vapor deposition (PECVD),could facilitate even higher degrees of conductivity. These techniques have profoundly impacted the microelectronics, photovoltaic, and display enhancement industries.

Transflective LCDs combine elements of both transmissive and reflective characteristics. Ambient light passes through the LCD and hits the semi-reflective layer. Most of the light is then reflected back through the LCD. However some of the light will not be reflected and will be lost. Alternately a backlight can be used to provide the light needed to illuminate the LCD if ambient light is low. Light from the backlight passes through a semi-reflective layer and illuminates the LCD. However as with ambient lighting some of the light does not penetrate the semi-reflective layer and is lost.

Transflective LCDs are used in devices that will operate in a wide variety of lighting conditions (from complete darkness to full sunlight). Under dim lighting conditions transflective LCDs offer visual performance similar to transmissive LCDs, whilst under bright lighting conditions they offer visual performance similar to reflective LCDs. However this performance is a tradeoff because the transflective mode is less efficient due to some light loss.

A simple transflective display is shown as below, in which there are two regions, T and R respectively. The cell gap in two regions are different, dT = 2*dR. This is to maintain the reflection and transmission from two regions are the same intensity, and give same color reproduction, because in the T region, light only goes through the LC layer once, while in the R region, light passes through twice.