define tft display in stock

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.

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.

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.

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.

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.

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.

TFT-based displays have a transistor for each pixel on the screen. This allows the electrical current that illuminates the display to be turned on and off at a faster rate, which makes the display brighter and shows motion smoother. LCDs that use TFT technology are called "active-matrix" displays, which are higher-quality than older "passive-matrix" displays. TFT technology provides the best resolution of all the flat display technologies, but it is also expensive than monochrome lcd. So TFTs are used in high-quality LCD displays, if you see a LCD monitor at your local computer market, it should be an active tft lcd display, Basically, it is a high-quality tft lcd monitor.

Passive-matrix display. A passive-matrix display is anLCD screen display that contains a series of wires that cross each other. See the dual scan display for a full definition on this term.

What is an Active-matrix Display (TFT)? Alternatively referred to as TFT ( thin-film transistor) and AMLCD ( active-matrix LCD ), an active-matrix display is an LCD ( liquid crystal display) introduced with the IBM ThinkPad in 1992.

It uses a matrix of thin film transistors(TFTs) and capacitors to control the image produced by thedisplay. The brightness of each pixel is controlled by modifying the electrical charge of the corresponding capacitors.

TFT stands for thin-film transistor and is used with LCD to improve image quality over older digital display technologies. Each pixel on a TFT LCD has its own transistor on the glass itself, which offers greater control over the images and colors that it renders.

TFT is also an abbreviation for other technical terms including time from transmission, text fix test, Trinitron flat tube, and trivial file transfer protocol.

Since the transistors in a TFT LCD screen are so small, the technology offers the added benefit of requiring less power. However, while TFT LCDs can deliver sharp images, they also tend to offer relatively poor viewing angles. The result is that TFT LCDs look best when viewed head-on, but viewing images from the side is often difficult.

TFT LCDs are found on low-end smartphones as well as basic cell phones. The technology is also used on TVs, handheld video game systems, computer monitors, and GPS navigation systems.

All the pixels on a TFT screen are configured in a row-and-column format, and each pixel is attached to an amorphous silicon transistor that rests directly on the glass panel. This allows each pixel to be given a charge and for the charge to be kept even when the screen is refreshed to produce a new image.

With this type of setup, the state of a particular pixel is being actively maintained even while other pixels are being used. This is why TFT LCDs are considered active matrix displays (as opposed to a passive matrix displays).

Lots of smartphone manufacturers use IPS-LCD (Super LCD), which provides wider viewing angles and richer colors, but newer phones feature displays that utilize OLED or Super-AMOLED technology. For example, Samsung"s flagship smartphones boast OLED panels, while most of Apple"s iPhones and iPads come equipped with an IPS-LCD. Super LCD and Super-AMOLED have their own pros and cons, but they both far exceed the capabilities of TFT LCD technology.

A thin-film transistor liquid crystal display (TFT LCD) is a type of liquid crystal display (LCD) that makes use of thin-film transistor technology in order to improve qualities such as contrast and addressability. TFT technology means that an individual transistor is used to drive each individual pixel, allowing for faster response times.

Thin-film transistor liquid crystal display technology uses "field-effect" transistors, which are built by layering thin films on a glass substrate, hence the name. This technique is commonly used for creating microprocessors. The TFT in the LCD controls individual pixels in the display by setting the level of the electric field across the three liquid crystal capacitors (one for each sub-pixel of red, green and blue) in the pixel in order to control the polarization of the crystal material. The amount of polarization in the crystal determines the amount of light that reaches the color filter from the backlight. Because of this ability to directly and quickly control each pixel, TFT is also called active-matrix LCD technology.

A TFT LCD monitor is a type of flat-panel display that works as either a computer monitor or as a display for a TV. TFT LCD is short for thin film transistor liquid crystal display. Most of the time, manufacturers shorten the term for such displays to LCD, dropping the TFT from the name since this abbreviation simply refers to the type of LCD monitor, and TFT is easily the most popular type.

The thin film transistor consists of a thin piece of a semiconductor material applied over a glass substrate. Each pixel has its own transistor along with the liquid crystal material. The liquid crystal material exhibits properties of both a liquid, because of its ability to change quickly, and a crystal, because of its ability to remain in an arranged position. The transistor applies a voltage to the pixel, determining its color and intensity. A pixel is short for picture element, and the tiny pixels blend together to create the image on a display.

Another name for a TFT LCD monitor is an active-matrix LCD. Although TFT is not the only active-matrix technology, it is overwhelmingly the most common type, causing some people use the two terms interchangeably. A TFT is only a small part of an active-matrix LCD, however. The term active-matrix refers to the ability of the monitor to control individual pixels and switch them quickly.

Active-matrix LCDs differ from passive-matrix LCDs in several ways. They have a high refresh rate, high contrast, and high response times, at least when compared to passive-matrix displays. A passive-matrix LCD is commonly found in a calculator display or a digital wristwatch, where the display contains a limited number of segments and does not require full color. Active-matrix displays usually are high-resolution, full-color LCDs, and they include those found in computer displays, cell phones, and TVs.

A few different types of thin film transistor technology may be are found in a TFT LCD monitor. The most common for computer displays and TVs is called a twisted nematic (TN) display, which features quick response times. TN displays do not excel in the areas of screen viewing angle and color reproduction, however. Another common monitor technology is IPS, short for in-plane switching. An IPS display offers great color and good viewing angles, but its refresh rates are slow.

TFT stands for thin-film transistor, which means that each pixel in the device has a thin-film transistor attached to it. Transistors are activated by electrical currents that make contact with the pixels to produce impeccable image quality on the screen. Here are some important features of TFT displays.Excellent Colour Display.Top notch colour contrast, clarity, and brightness settings that can be adjusted to accommodate specific application requirements.Extended Half-Life.TFT displays boast a much higher half-life than their LED counterparts and they also come in a variety of size configurations that can impact the device’s half-life depending on usage and other factors.TFT displays can have either resistive or capacitive touch panels.Resistive is usually the standard because it comes at a lower price point, but you can also opt for capacitive which is compatible with most modern smartphones and other devices.TFT displays offer exceptional aspect ratio control.Aspect ratio control contributes to better image clarity and quality by mapping out the number of pixels that are in the source image compared to the resolution pixels on the screen.Monitor ghosting doesn’t occur on TFT displays.This is when a moving image or object has blurry pixels following it across the screen, resembling a ghost.

TFT displays are incredibly versatile.The offer a number of different interface options that are compatible with various devices and accommodate the technical capabilities of all users.

There are two main types of TFT LCD displays:· Twisted nematic TFT LCDs are an older model. They have limited colour options and use 6 bits per each blue, red, and green channel.

In-plane switching TFT LCDs are a newer model. Originally introduced in the 1990s by Hitachi, in-plane switching TFT LCDs consist of moving liquid pixels that move in contrast or opposite the plane of the display, rather than alongside it.

The type of TFT LCD monitor or industrial display you choose to purchase will depend on the specifications of your application or project. Here are a few important factors to consider when selecting an appropriate TFT LCD display technology:Life expectancy/battery life.Depending on the length of ongoing use and the duration of your project, you’re going to want to choose a device that can last a long time while maintaining quality usage.

Image clarity.Some TFT displays feature infrared touchscreens, while others are layered. The former is preferable, especially in poor lighting conditions or for outdoor and industrial applications, because there’s no overlay and therefore no obstructions to light emittance.

The environmental conditions make a difference in operation and image clarity. When choosing a TFT for outdoor or industrial applications, be sure to choose one that can withstand various environmental elements like dust, wind, moisture, dirt, and even sunlight.

As a leading manufacturer and distributor of high-quality digital displays in North America, Nauticomp Inc. can provide custom TFT LCD monitor solutions that are suitable for a multitude of industrial and commercial indoor and outdoor applications. Contact us today to learn more.

A thin-film transistor liquid crystal display, TFT LCD display for short, is a type of LCD display that uses thin-film transistor technology to improve image quality.

TFT LCD displays have many advantages over traditional LCD displays. While traditional LCDs use a single layer of transistors, TFT LCDs use a thin film of transistors. This allows for better image quality, as well as improved response time and lower power consumption. TFT LCDs are also thinner and lighter than traditional LCDs, making them ideal for use in portable devices.

When choosing a TFT LCD, it is important to consider the viewing angle and colour reproduction. While TFT IPS displays offer better image quality, they are also more expensive.

TFT LCDs are used in a wide variety of industries, including consumer electronics, computing, telecommunications, automotive, and medical to name a few. Specifically, they are used in:Computers and laptop computers

TFT LCDs use two types of cover glass. Rigid cover glass is made of either soda-lime glass or Gorilla Glass. Flexible cover glass is used in some TFT LCDs, such as those used in mobile phones. The flexible cover glass is more resistant to breakage than rigid cover glass, making it ideal for use in portable devices.

The touchscreen is an optional part of the display module that allows the user to interact with the display. A touchscreen is a layer of glass that is coated with a material that is sensitive to pressure. When the user presses on the touchscreen, the pressure is registered and converted into an electrical signal.

Nauticomp Inc. is a leading provider of industrial LCD displays. Our products are designed for use in a variety of industries, including maritime, aerospace, and military. We offer a wide range of LCDs, including TFT LCDs, OLEDs, and LEDs. Contact us today to learn more about our products and services.

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

2020 – TFT LCD display technology dominants the display market now. Within the last 20 years, it has wiped out the market of CRT (cathode-ray tube) and Plasma. The only challenges are OLED (organic light-emitting diode)and Micro LED (Maybe, still in lab).

TFT LCD Display (Thin-Film-Transistor Liquid Crystal Display) technology has a sandwich-like structure with liquid crystal material filled between two glass plates. Two polarizer filters, color filters (RGB, red/green/blue) and two alignment layers determine exactly the amount of light is allowed to pass and which colors are created.

Each pixel in an active matrix is paired with a transistor that includes a capacitor which gives each sub-pixel the ability to retain its charge, instead of requiring an electrical charge sent each time it needed to be changed.  The TFT layer controls light flow a color filter displays the color and a top layer houses your visible screen.

Utilizing an electrical charge that causes the liquid crystal material to change their molecular structure allowing various wavelengths of backlight to “pass-through”. The active matrix of the TFT display is in constant flux and changes or refreshes rapidly depending upon the incoming signal from the control device.

The pixels of TFT displays are determined by the underlying density (resolution) of the color matrix and TFT layout. The more pixels the higher detail is available.Available screen size, power consumption, resolution, interface (how to connect) define the TFT displays.

The pixels of TFT displays are determined by the underlying density (resolution) of the color matrix and TFT layout. The more pixels the higher detail is available. Available screen size, power consumption, resolution, interface (how to connect) define the TFT displays.

The TFT screen itself can’t emit light like OLED display, it has 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 and therefore utilize less power and require less depth by design.

TFT is a Thin Film Transistor, TFT refers to each LCD liquid crystal display pixels that are driven by integration in the behind of the Thin Film Transistor. Therefore, the TFT-type display has the advantages of high responsiveness, high brightness, and high contrast, and its display effect is close to that of CRT display, TFT-LCD is one of the most liquid crystal displays.TFT display is also a kind of active-matrix liquid crystal display equipment. TFT-LCD is one of the best LCD color displays, TFT-LCD has the advantages of fine and vivid image, lightweight, low power consumption, and good environmental protection performance, widely used in TV, laptop, mobile phone, monitor, medical beauty, and other equipment.

Unlike TN, TFT displays are “backlit” – the imaginary light path is not from top to bottom, as in TN, but from bottom to top. In this way, a special light tube is set on the back of the liquid crystal, and the light source shines upward through the lower polarizer. Since the upper and lower interlayer electrodes are changed into FET electrodes and common electrodes, the performance of liquid crystal molecules will also change when the FET electrode is switched on. The display purpose can be achieved through shading and light transmission, and the response time is greatly improved to about 80ms.TFT is commonly known as “true color” because it has higher contrast and richer colors than TN-LCD, and the screen updates faster.

The main feature of TFT-LCD, as opposed to TN, is one semiconductor switch per pixel. Because each pixel can be directly controlled by point pulses. Therefore, each node is relatively independent and can be controlled continuously. Such a design method not only improves the response speed of the display screen but also can accurately control the display grayscale, which is why TFT color is more realistic than DSTN.

The TFT panel is cut from a larger substrate. LCD products also have a large array of transistors to control the three primary colors, and current manufacturing technology is difficult to ensure that tens or even hundreds of millions of transistors on a large substrate are without a single problem. If there is a problem with one of the transistors, then the corresponding color of the corresponding point of the transistor will go wrong (only a certain fixed color can be displayed), and this point is commonly called “bad point”. The probability of bad spots is not fixed in position, so a substrate is likely to be wasted a lot. Generally, LCD requires that the bad point is less than 5, and some large manufacturers have narrowed the standard to 3, or even 0, which will reduce the yield rate. Some smaller manufacturers expand the bad points, which naturally reduces costs and quality, which is one reason why some manufacturers have been able to slash prices.

Although there are many manufacturers capable of producing LCDs, there are only a handful of manufacturers capable of producing TFT panels.ACER, as a well-known enterprise in the IT industry, is quite powerful. Although IT does not have the ability to produce TFT panels by itself,

The display sets the electron, the communication and the information processing technology in one body, is considered as the electron industry after the 20th-century microelectronics, the computer another important development opportunity.

With the rapid development of science and technology, a revolution is taking place in display technology. After more than 20 years of research, competition, and development, the flat-panel display has entered the role and become the mainstream of display products in the new century. There are four types of flat-panel displays with the most fierce competition:

The principle of field emission flat display is similar to that of CRT, which only has one to three electron guns and up to six. The field emission display adopts an electron gun array (electron emission micro tip array, such as diamond film tip cone), and the display with a resolution of VGA (640×480×3) needs 921,600 electron emission micro tips with uniform performance.

Glow plasma display are through small vacuum plasma discharge excitation discharge cavity light-emitting materials, luminous effect, and low power consumption is its shortcomings (only 1.2 lm/W, and lamp luminous efficiency more than 80 lm/W, 6 watts per square inch display area), but in 102 ~ 152 cm diagonal field of the large-screen display has a strong competitive advantage.

The semiconductor light-emitting diode (LED) display scheme, due to the successful development of GaN blue light-emitting diode, has won absolute control over the market of the video display with very large screens, but this kind of display is only suitable for large outdoor displays, and video display with a small and medium screen does not have its market.

Special TFT – LCD, LCD flat panel display, is the only one in the brightness, contrast, such as power, life, volume and weight of integrated performance to catch up with and surpass that of the CRT display device, it features good performance, large-scale production, a high degree of automation, low cost of raw materials, the vast development space, will quickly become the mainstream product of the new century, is one of the highlights of the 21st-century global economic growth.

TFT-LCD, which USES liquid crystal as the excellent characteristic of the light valve, divides the luminous display device into two parts, namely the light source and the control of the light source. As a light source, no matter from luminous efficiency, full color, or life, has achieved brilliant results, but also in continuous deepening. Since the invention of the LCD, the backlight has been continuously improved, from monochrome to color, from thick to thin, from side fluorescent lamps to flat fluorescent lamps. The latest achievements in light sources will provide a new backlight for LCD. With the progress of light source technology, there will be newer and better light sources and LCD applications. Is the control of the light source, the rest of the large scale integrated circuit technology and semiconductor technology transplanted, successfully developed the thin film transistor (TFT) production technology, implements the matrix addressing the control of the liquid crystal light valve, solved the LCD light valve and the controller, so that the advantages of liquid crystal display (LCD).

The TFT thin-film transistor (matrix) — which “actively” controls individual pixels on the screen — is the origin of the so-called active matrix TFT.So how exactly do images come about? The basic principle is simple: a display screen consists of a number of pixels that can emit light of any color, and controlling each pixel to display a corresponding color does the trick. In TFT LCD, backlight technology is generally adopted. In order to accurately control the color and brightness of each pixel, a switch similar to a shutter needs to be installed after each pixel. When the “shutter” is opened, light can come through, but when the “shutter” is closed, light cannot come through.

Of course, it’s not as simple technically as that. Liquid Crystal Display USES the properties of Liquid crystals (Liquid when heated and solid when cooled)

Liquid crystal displays (LCDs) are filamentous, and their molecular structure changes as the environment change, giving them different physical properties — allowing light to pass through or block it — in the case of louvers.

You know the three primary colors, so each pixel on the display needs to be made up of three similar basic components described above, which control the red, green, and blue colors respectively.

TFT color filter is divided into red, green, and blue according to the color, which is successively arranged on the glass substrate to form a group (dot pitch) corresponding to a pixel. Each monochrome filter is called a sub-pixel. That said, if a TFT display supports a maximum resolution of 1280×1024, it needs at least 1280×3×1024 sub-pixels and transistors. For a 15-inch TFT display (1024 x 768), a pixel is about 0.0188 inches.

As you know, pixels are critical to a display, and the smaller each pixel, the larger the maximum possible resolution of the display. But because of the physical limitations of transistors, the TFT is roughly 0.0117 inches (0.297mm) per pixel, so the maximum resolution for a 15-inch display is 1,280 by 1,024.[1]

TFT technology is the basis of liquid crystal (LC), inorganic and organic thin-film electroluminescence (EL and OEL) flat panel displays.TFT is a kind of film necessary for manufacturing circuits formed by sputtering and chemical deposition process on the non-single wafers such as glass or plastic substrate, and large-scale semiconductor integrated circuit (LSIC) is produced by processing of the film. Using non-single-crystal substrate can greatly reduce the cost, which is the extension of traditional LSI to large-area, multi-function, and low-cost direction.

The first generation of large-area glass substrate (300mm×400mm) TFT-LCD production line was put into production in the early 1990s. By the first half of 2000, the area of glass substrate has been expanded to 680mm×880mm), and the recent 950mm×1200mm glass substrate will also be put into operation. In principle, there is no area limit.

The 1.3-inch TFT chip used for liquid crystal projection has a resolution of one million pixels in XGA.The resolution of the SXGA (1280×1024) 16.1-inch TFT array amorphous silicon film thickness is only 50nm, and the TAB ON GLASS and SYSTEM ON GLASS technology, its IC integration, requirements for equipment and supply technology, technical difficulty than the traditional LSI.

TFT was first used as a matrix location circuit to improve the optical valve characteristics of liquid crystals. For high-resolution displays, the accurate control of object elements is realized through voltage adjustment in the range of 0-6v (its typical value is 0.2 to 4V), thus making it possible for LCD to achieve a high-quality high-resolution display.TFT-LCD is the first flat panel display in human history to surpass CRT in display quality. Now people are starting to integrate the drive IC into the glass substrate, and the whole TFT will be more powerful than traditional large-scale semiconductor integrated circuits.

Low voltage applications, low drive voltage, solid use safety, and reliability improvement; Flat, light, and thin, saving a lot of raw materials and space; Low power consumption, its power consumption is about one-tenth of the CRT display, reflective TFT-LCD is only about one percent of the CRT, saving a lot of energy; TFT-LCD products also have specifications, models, size series, variety, convenient and flexible use, maintenance, update, upgrade easy, long service life and many other characteristics. The display range covers the application range of all monitors from 1 inch to 40 inches and the large projection plane, which is a full-size display terminal; Display quality from the simplest monochrome character graphics to high resolution, high color fidelity, high brightness, high contrast, the high response speed of various specifications of video display; Display mode has direct vision type, projection type, perspective type, and reflection type.

No radiation, no flicker, no harm to the user’s health. In particular, the appearance of TFT-LCD electronic books and periodicals will bring mankind into the era of a paperless office and paperless printing, and trigger the revolution of human learning, communication, and recording civilization.

The temperature range from -20℃ to +50℃ can be used normally, and the low temperature working temperature of TFT-LCD after temperature reinforcement can reach -80 ℃. It can be used as a mobile terminal display, desktop terminal display, and large screen projection TV. It is a full-size video display terminal with excellent performance.

A TFT LCD,  or a thin film transistor liquid crystal display, is one of the fastest growing forms of display technology today. The thin film transistor (TFT) is a type of semiconductor device used in display technology to enhance efficiency, compactness, and cost of the product. In conjunction with its semiconductor properties, the TFT LCD is an active matrix display, controlling pixels individually and actively rather than passively, furthering the benefits of this semiconductor device.

The TFT LCD is built with three key layers. Two sandwiching layers consist of glass substrates, though one includes TFTs while the other has an RGB, or red green blue, color filter. The layer between the glass layers is a liquid crystal layer.

The Architecture of a TFT Pixelbelow) from the other substrate layer of the device and control the amount of voltage applied to their respective sub-pixels. This layer also has pixel electrodes between the substrate and the liquid crystal layer. Electrodes are conductors that channel electricity into or out of something, in this case, pixels.

Between the two substrate layers lie liquid crystals. Together, the liquid crystal molecules may behave as a liquid in terms of movement, but it holds its structure as a crystal. There are a variety of chemical formulas available for use in this layer. Typically, liquid crystals are aligned to position the molecules in a certain way to induce specific behaviors of passing light through the polarization of the light waves. To do this, either a magnetic or electric field must be used; however, with displays, for a magnetic field to be usable, it will be too strong for the display itself, and thus electric fields, using very low power and requiring no current, are used.

Before applying an electric field to the crystals between the electrodes, the alignment of the crystals is in a 90 degree twisted pattern, allowing a properly crystal-polarized light to pass through the surface polarizer in a display’s “normal white” mode. This state is caused by electrodes that are purposely coated in a material that orients the structure with this specific twist.

However, when the electric field is applied, the twist is broken as the crystals straighten out, otherwise known as re-aligning. The passing light can still pass through the back polarizer, but because the crystal layer does not polarize the lights to pass through the surface polarizer, light is not transmitted to the surface, thus an opaque display. If the voltage is lessened, only some crystals re-align, allowing for a partial amount of light to pass and creating different shades of grey (levels of light). This effect is called the twisted nematic effect.

Fig. 3:The top row characterizes the nature of alignment in using IPS as well as the quality of viewing angles. The bottom row displays how the twisted nematic is used to align the crystals and how viewing angles are affected by it.

The light that passes through the device is sourced from the backlight which can shine light from the back or the side of the display. Because the LCD does not produce its own light, it needs to use the backlight in the OLED) have come into use as well. Typically white, this light, if polarized correctly, will pass through the RGB color filter of the surface substrate layer, displaying the color signaled for by the TFT device.

Let us start with the basics first; refresh the knowledge about TN and LCD displays in general, later we will talk about TFTs (Thin Film Transistors), how they differ from regular monochrome LCD displays. Then we will go on to the ghosting effect, so we will not only discuss the technology behind the construction of the TFT, but also some phenomena, like the ghosting effect, or grayscale inversion, that are important to understand when using an LCD TFT display.

Next, we will look at different technologies of the TFT LCD displays like TN, IPS, VA, and of course about transmissive and transflective LCD displays, because TFT displays also can be transmissive and transflective. In the last part we will talk about backlight.

Let us start with a short review of the most basic liquid crystal cell, which is the TN (twisted nematic) display. On the picture above, we can see that the light can be transmit through the cell or blocked by the liquid crystal cell using voltage. If you want to learn more about monochrome LCD displays and the basics of LCD displays, follow this link.

What is a TFT LCD display and how it is different from a monochrome LCD display? TFT is called an active display. Active, means we have one or more transistors in every cell, in every pixel and in every subpixel. TFT stands for Thin Film Transistor, transistors that are very small and very thin and are built into the pixel, so they are not somewhere outside in a controller, but they are in the pixel itself. For example, in a 55-inch TV set, the TFT display contains millions of transistors in the pixels. We do not see them, because they are very small and hidden, if we zoom in, however, we can see them in every corner of each pixel, like on the picture below.

On the picture above we can see subpixels, that are basic RGB (Red, Green, Blue) colors and a black part, with the transistors and electronic circuits. We just need to know that we have pixels, and subpixels, and each subpixel has transistors. This makes the display active, and thus is called  the TFT display. TFT displays are usually color displays, but there are also monochrome TFT displays, that are active, and have transistors, but have no colors. The colors in the TFT LCD display are typically added by color filters on each subpixel. Usually the filters are RGB, but we also have RGBW (Red, Green, Blue, White) LCD displays with added subpixels without the filter (White) to make the display brighter.

Going a little bit deeper, into the TFT cell, there is a part inside well known to us from the monochrome LCD display Riverdi University lecture. We have a cell, liquid crystal, polarizers, an ITO (Indium Tin Oxide) layer for the electrodes, and additionally an electronic circuit. Usually, the electronic circuit consists of one transistor and some capacitors to sustain the pixel state when we switch the pixel OFF and ON. In a TFT LCD display the pixels are much more complicated because apart from building the liquid crystal part, we also need to build an electronic part.

That is why TFT LCD display technologies are very expensive to manufacture. If you are familiar with electronics, you know that the transistor is a kind of switch, and it allows us to switch the pixel ON and OFF. Because it is built into the pixel itself, it can be done very quickly and be very well controlled. We can control the exact state of every pixel not only the ON and OFF states, but also all the states in between. We can switch the light of the cells ON and OFF in several steps. Usually for TFT LCD displays it will be 8-bit steps per color, so we have 256 steps of brightness for every color, and every subpixel. Because we have three subpixels, we have a 24-bit color range, that means over 16 million combinations, we can, at least theoretically, show on our TFT LCD display over 16 million distinct colors using RGB pixels.

Now that we know how the TFT LCD display works, we can now learn some practical things one of which is LCD TFT ghosting. We know how the image is created, but what happens when we have the image on the screen for a prolonged time, and how to prevent it. In LCD displays we have something called LCD ghosting. We do not see it very often, but in some displays this phenomenon still exists.

If some elements of the picture i.e., your company logo is in the same place of the screen for a long period of time, for couple of weeks, months or a year, the crystals will memorize the state and later, when we change the image, we may see some ghosting of those elements. It really depends on many conditions like temperature and even the screen image that we display on the screen for longer periods of time. When you build your application, you can use some techniques to avoid it, like very rapid contrast change and of course to avoid the positioning the same image in the same position for a longer time.

You may have seen this phenomenon already as it is common in every display technology, and even companies like Apple put information on their websites, that users may encounter this phenomenon and how to fix it. It is called image ghosting or image persistence, and even Retina displays are not free of it.

Another issue present in TFT displays, especially TN LCD displays, is grayscale inversion. This is a phenomenon that changes the colors of the screen according to the viewing angle, and it is only one-sided. When buying a TFT LCD display, first we need to check what kind of technology it is. If it is an IPS display, like the Riverdi IPS display line, then we do not need to worry about the grayscale inversion because all the viewing angles will be the same and all of them will be very high, like 80, 85, or 89 degrees. But if you buy a more common or older display technology type, like the TN (twisted nematic) display, you need to think where it will be used, because one viewing angle will be out. It may be sometimes confusing, and you need to be careful as most factories define viewing direction of the screen and mistake this with the greyscale inversion side.

On the picture above, you can see further explanation of the grayscale inversion from Wikipedia. It says that some early panels and also nowadays TN displays, have grayscale inversion not necessary up-down, but it can be any angle, you need to check in the datasheet. The reason technologies like IPS (In-Plane Switching), used in the latest Riverdi displays, or VA, were developed, was to avoid this phenomenon. Also, we do not want to brag, but the Wikipedia definition references our website.

We know already that TN (twisted nematic) displays, suffer from grayscale inversion, which means the display has one viewing side, where the image color suddenly changes. It is tricky, and you need to be careful. On the picture above there is a part of the LCD TFT specification of a TN (twisted nematic) display, that has grayscale inversion, and if we go to this table, we can see the viewing angles. They are defined at 70, 70, 60 and 70 degrees, that is the maximum viewing angle, at which the user can see the image. Normally we may think that 70 degrees is better, so we will choose left and right side to be 70 degrees, and then up and down, and if we do not know the grayscale inversion phenomena, we may put our user on the bottom side which is also 70 degrees. The viewing direction will be then like a 6 o’clock direction, so we call it a 6 o’clock display. But you need to be careful! Looking at the specification, we can see that this display was defined as a 12 o’clock display, so it is best for it to be seen from a 12 o’clock direction. But we can find that the 12 o’clock has a lower viewing angle – 60 degrees. What does it mean? It means that on this side there will be no grayscale inversion. If we go to 40, 50, 60 degrees and even a little bit more, probably we will still see the image properly. Maybe with lower contrast, but the colors will not change. If we go from the bottom, from a 6 o’clock direction where we have the grayscale inversion, after 70 degrees or lower we will see a sudden color change, and of course this is something we want to avoid.

To summarize, when you buy older technology like TN and displays, which are still very popular, and Riverdi is selling them as well, you need to be careful where you put your display. If it is a handheld device, you will see the display from the bottom, but if you put it on a wall, you will see the display from the top, so you need to define it during the design phase, because later it is usually impossible or expensive to change the direction.

We will talk now about the other TFT technologies, that allow us to have wider viewing angles and more vivid colors. The most basic technology for monochrome and TFT LCD displays is twisted nematic (TN). As we already know, this kind of displays have a problem with grayscale inversion. On one side we have a higher retardation and will not get a clear image. That is why we have other technologies like VA (Vertical Alignment), where the liquid crystal is differently organized, and another variation of the TFT technology – IPS which is In-Plane Switching. The VA and IPS LCD displays do not have a problem with the viewing angles, you can see a clear image from all sides.

Apart from the different organization of the liquid crystals, we also organize subpixels a little bit differently in a VA and IPS LCD displays. When we look closer at the TN display, we will just see the subpixels with color filters. If we look at the VA or IPS display they will have subpixels of subpixels. The subpixels are divided into smaller parts. In this way we can achieve even wider viewing angles and better colors for the user, but of course, it is more complicated and more expensive to do.

The picture above presents the TN display and grayscale inversion. For IPS or VA technology there is no such effect. The picture will be the same from all the sides we look so these technologies are popular where we need wide viewing angles, and TN is popular where we don’t need that, like in monitors. Other advantages of IPS LCD displays are they give accurate colors, and wide viewing angles. What is also important in practice, in our projects, is that the IPS LCD displays are less susceptible to mechanical force. When we apply mechanical force to the screen, and have an optically bonded touch screen, we push the display as well as squeeze the cells. When we have a TN display, every push on the cell changes the image suddenly, with the IPS LCD displays with in-plane switching, different liquid crystals organization, this effect is lesser. It is not completely removed but it is much less distinct. That is another reason IPS displays are very popular for smartphones, tablets, when we have the touchscreens usually optically bonded.

If we wanted to talk about disadvantages, there is a question mark over it, as some of them may be true, some of them do not rely on real cases, what kind of display, what kind of technology is it. Sometimes the IPS displays can have higher power consumption than others, in many cases however, not. They can be more expensive, but not necessarily. The new IPS panels can cost like TN panels, but IPS panels definitely have a longer response time. Again, it is not a rule, you can make IPS panels that are very fast, faster than TN panels, but if you want the fastest possible display, probably the TN panel will be the fastest. That is why the TN technology is still popular on the gaming market. Of course, you can find a lot of discussions on the internet, which technology is better, but it really depends on what you want to achieve.

Now, let us look at the backlight types. As we see here, on the picture above, we have four distinct types of backlight possible. The most common, 95 or 99 per cent of the TFT LCD displays on the market are the transmissive LCD display type, where we need the backlight from the back. If you remember from our Monochrome LCD Displays lecture, for transmissive LCD displays you need the backlight to be always on. If you switch the backlight off, you will not see anything. The same as for monochrome LCD displays, but less popular for TFT displays, we have the transflective LCD display type. They are not popular because usually for transflective TFT displays, the colors lack in brightness, and the displays are not very practical to use. You can see the screen, but the application is limited. Some transflective LCD displays are used by military, in applications where power consumption is paramount; where you can switch the backlight off and you agree to have lower image quality but still see the image. Power consumption and saving energy is most important in some kind of applications and you can use transflective LCD displays there. The reflective type of LCD displays are almost never used in TFT. There is one technology called Low Power Reflective Displays (LPRD) that is used in TFT but it is not popular. Lastly, we have a variation of reflective displays with frontlight, where we add frontlight to the reflective display and have the image even without external light.

Just a few words about Low Power Reflective Displays (LPRD). This kind of display uses environmental light, ambient light to reflect, and produce some colors. The colors are not perfect, not perfectly clear, but this technology is becoming increasingly popular because it allows to have color displays in battery powered applications. For example, a smartwatch would be a case for that technology, or an electrical bike or scooter, where we can not only have a standard monochrome LCD display but also a TFT LCD color display without the backlight; we can see the image even in

strong sunlight and not need backlight at all. So, this kind of TFL LCD display technology is getting more and more popular when we have outdoor LCD displays and need a low power consumption.

On the picture above, we have some examples of how transmissive and reflective LCD displays work in the sunlight. If we have a simple image, like a black and white pattern, then on a transmissive LCD display, even with 1000 candela brightness, the image probably will be lower quality than for a reflective LCD display; if we have sunlight, we have very strong light reflections on the surface of the screen. We have talked about contrast in more detail in the lecture Sunlight Readable Displays. So, reflective LCD displays are a better solution for outdoor applications than transmissive LCD displays, where you need a really strong backlight, 1000 candela or more, to be really seen outdoors.

To show you how the backlight of LCD displays is built, we took the picture above. You can see the edge backlight there, where we have LEDs here on the small PCB on the edge, and we have a diffuser that distributes the light to the whole surface of LCD screen.

In addition to the backlight, we have something that is called a frontlight. It is similar to backlight, it also uses the LEDs to put the light into it, but the frontlight needs to be transparent as we have the display behind. On the example on the picture above we can see an e-paper display. The e-paper display is also a TFT display variation, but it is not LCD (liquid crystal), it is a different technology, but the back of the display is the same and it is reflective. The example you see is the Kindle 4 eBook reader. It uses an e-paper display and a frontlight as well, so you can read eBooks even during the night.

While buying a television, computer or a mobile, you would have come across the term TFT and wondered what it really meant. Simply put, TFT stands for “Thin Film Transistor”.

It is a type of LCD flat-panel display screen, wherein each pixel is controlled by one to four transistors. Also known as active-matrix LCDs, TFT technology offers the best resolution of all the flat-panel techniques. However, that makes it one of the most expensive ones too.

TFT transistors are normally used in high-quality flat-panel LCDs. Such displays come with at least one transistor for each pixel on the screen. This makes it possible for the electrical current that illuminates the display to be turned on and off quicker. This, in turn, results in brighter display and smoother motions. LCDs with TFT technology are active-matrix displays and are higher-quality than the older passive-matrix displays. Active matrix simply means that every pixel is attached to an individual transistor and capacitor.

So, the next time you see a label TFT AM LCD monitor at your local computer store, don’t be baffled. It simply means that the monitor comes with a “thin-film transistor active-matrix liquid crystal display”. In other words, it is an excellent flat-screen monitor. Good colours make everything look brighter and more appealing.

Design is no longer about what things look like and feel like. Design is more about how it works. As such, the TFT LCD modules on our TV, computer monitors, kindles, mobile phone and navigation systems are all excellent designs. They are not only highly effective but also add to the look and feel of the devices.

Less energy consumption – because of the construction of TFT structures with pixel-like materials, they do not consume too much energy, to begin with. When compared with the CRT monitor, the TFT monitor consumes far less power and is therefore a preferred choice.

Sharper visibility with superb visual quality - the images displayed on a TFT display do not rely on scanning the electron beams. Hence they are flicker-free and offer a crisp image, with no geometric distortion.

Excellent physical design – the physical design of TFT display is in such a manner that they save a lot of space. The devices can be placed anywhere in the office or home even if there is very little space available.

Faster response time – as there are individual transmitters and conductors, the response time is much faster than that of the normal LCD or CRT displays. There is virtually no delay in turning on the screen, which makes it preferable to other types of displays.

Low strain on the eye – thanks to the quality of pictures displayed and the absence of any rays emitting from the screen, viewing is rather pleasant and strain-free for the eyes.

Poor viewing experience at angles – TFT screen offers the best viewing experience right at the front. Any change in the angle of view could mean a distorted view. Still, TFT displays are far superior in quality than the older versions and would be expected to improve in the future.

Technology is ever-changing. So it is no wonder TFT is also undergoing frequent changes. For instance, now you have IPS. It stands for In-Plane Switching and is a further improvement on TFT LCDs.

Although energy consumption is low compared to TFT LCDs, and they are better than TFT LCDs, they are more expensive. But IPS TFT LCD technology is now widely used for high-performance computers, laptops, tablets, and smart phones.

Display screen is everywhere nowadays. Do you still remember the TVs or computer monitors 20 years ago? They were quadrate, huge and heavy. Now let’s look at the flat, thin and light screen in front of you, have you ever wondered why is there such a big difference?

Actually, the monitors 20 year ago were CRT (Cathode Ray Tube) displays, which requires a large space to run the inner component. And now the screen here in your presence is the LCD (Liquid Crystal Display) screen.

As mentioned above, LCD is the abbreviation of Liquid Crystal Display. It’s a new display technology making use of the optical-electrical characteristic of liquid crystal.

Liquid crystal is a state of substance that has both the characteristics of liquid and solid crystal. It don’t emit light itself, but it can let the light pass perfectly in specific direction. Meanwhile, liquid crystal molecule will rotate under the influence of a electric field, and then the light goes through it will rotate too. That said, liquid crystal can be a switch of light, which is the key in display technology.

STN LCD: STN is for Super-twisted Nematic. The liquid crystal in STN LCD rotate more angles than that in TN LCD, and have a different electrical feature, allowing STN LCD to display more information. There are many improved version of STN LCD like DSTN LCD (double layer) and CSTN LCD (color). This LCD is used in many early phones, computers and outdoor devices.

TFT LCD: TFT is for Thin Film Transistor. It’s the latest generation of LCD technology and has been applied in all the displaying scenario including electronic devices, motor cars, industrial machines, etc. When you see the word ‘transistor’, you may realize there’s integrated circuits in TFT LCD. That’s correct and the secret that TFT LCD has the advantage of high resolution and full color display.

In a simple way, we can divide TFT LCD into three parts, from bottom to top they are: light system, circuit system and light and color control system.In manufacturing process, we’ll start from inner light and color control system and then stretch out to whole module.

It’s accustomed to divide TFT LCD manufacturing process into three main part: array, cell and module. The former two steps are about the production of light and color control system, which contains TFT, CF (color filter) and LC (liquid crystal), named a cell. And the last step is the assembly of cell, circuit and light system.

Now let’s turn to the production of TFT and CF. Here is a common method called PR (photoresist) method. The whole process of PR method will be demonstrated in TFT production.

As a display device TFT stands for Thin Film Transistor and is used to enhance the operation and usefulness of LCD displays. An LCD is a fluidic display device that uses a crystalline filled liquid to manipulate a rear illumination polarized source by means of an electrostatic field between two thin transparent metal conductors such as indium tin oxide (ITO) in order to present an image to the viewer. This process can be used in both segmented or pixelated display devices but is found synonymous with color TFT displays.

When an LCD is used to display moving images the inherent slow rate of change between fluid states over a large number of pixel elements can be a problem due in part to capacitive effects, which causes moving image blurring. By putting a high speed LCD controlling device in the form of a thin film transistor right at the pixel element on the glass surface, the LCD image speed issue can be greatly enhanced and for all practical purposes eliminates image blurring.

Other benefits of these thin film transistors are they allow for thinner display designs and different pixel designs and arrangements to vastly improve display viewing angles.

TFT displays are found in many applications these days, from mobile devices, appliance, medical devices, instrumentation, aircraft and certainly computer display devices as well as TV’s. The addition of the thin film transistor in LCD design vastly improved the use of LCD’s in all mar