tft lcd display working factory

When compared to the ordinary LCD, TFT LCD gives very sharp and crisp picture/text with shorter response time. TFT LCD displays are used in more and more applications, giving products better visual presentation.

TFT is an abbreviation for "Thin Film Transistor". The colorTFT LCD display has transistors made up of thin films of Amorphous silicon deposited on a glass. It serves as a control valve to provide an appropriate voltage onto liquid crystals for individual sub-pixels. That is why TFT LCD display is also called Active Matrix display.

A TFT LCD has a liquid crystal layer between a glass substrate formed with TFTs and transparent pixel electrodes and another glass substrate with a color filter (RGB) and transparent counter electrodes. Each pixel in an active matrix is paired with a transistor that includes 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. This means that TFT LCD displays are more responsive.

To understand how TFT LCD works, we first need to grasp the concept of field-effect transistor (FET). FET is a type of transistor which uses electric field to control the flow of electrical current. It is a component with three terminals: source, gate, and drain. FETs control the flow of current by the application of a voltage to the gate, which in turn alters the conductivity between the drain and source.

Using FET, we can build a circuit as below. Data Bus sends signal to FET Source, when SEL SIGNAL applies voltage to the Gate, driving voltage is then created on TFT LCD panel. A sub-pixel will be lit up. A TFT LCD display contains thousand or million of such driving circuits.

Topway started TFT LCD manufacturing more than15 years ago. We produce color TFT LCD display from 1.8 to 15+ inches with different resolutions and interfaces. Here is some more readings about how to choose the right TFT LCD.

Important technical improvements of LCD, such as LED backlighting and wide viewing Angle, are directly related to LCD. And account for an LCD display 80% of the cost of the LCD panel, enough to show that the LCD panel is the core part of the entire display, the quality of the LCD panel, can be said to directly determine the quality of an LCD display.

The production of civil LCD displays is just an assembly process. The LCD panel, the main control circuit, shell, and other parts of the main assembly, basically will not have too complex technical problems.

Does this mean that LCDS are low-tech products? In fact, it is not. The production and manufacturing process of the LCD panels is very complicated, requiring at least 300 process processes. The whole process needs to be carried out in a dust-free environment and with precise technology.

The general structure of the LCD panel is not very complex, now the structure of the LCD panel is divided into two parts: the LCD panel and the backlight system.

Due to the LCD does not shine, so you need to use another light source to illuminate, the function of the backlight system is to this, but currently used CCFL lamp or LED backlight, don’t have the characteristics of the surface light source, so you need to guide plate, spreadsheet components, such as linear or point sources of light evenly across the surface, in order to make the entire LCD panel on the differences of luminous intensity is the same, but it is very difficult, to achieve the ideal state can be to try to reduce brightness non-uniformity, the backlight system has a lot to the test of design and workmanship.

In addition, there is a driving IC and printed circuit board beside the LCD panel, which is mainly used to control the rotation of LCD molecules in the LCD panel and the transmission of display signals. The LCD plate is thin and translucent without electricity. It is roughly shaped like a sandwich, with an LCD sandwiched between a layer of TFT glass and a layer of colored filters.

LCD with light refraction properties of solid crystals, with fluid flow characteristics at the same time, under the drive of the electrode, can be arranged in a way that, in accordance with the master want to control the strength of the light through, and then on the color filter, through the red, green, blue three colors of each pixel toning, eventually get the full-screen image.

According to the functional division, the LCD panel can be divided into the LCD panel and the backlight system. However, to produce an LCD panel, it needs to go through three complicated processes, namely, the manufacturing process of the front segment Array,the manufacturing process of the middle segment Cell, and the assembly of the rear segment module. Today we will be here, for you in detail to introduce the production of the LCD panel manufacturing process.

The manufacturing process of the LCD panel Array is mainly composed of four parts: film, yellow light, etch and peel film. If we just look at it in this way, many netizens do not understand the specific meaning of these four steps and why they do so.

First of all, the motion and arrangement of LCD molecules need electrons to drive them. Therefore, on the TFT glass, the carrier of LCD, there must be conductive parts to control the motion of LCD. In this case, we use ITO (Indium Tin Oxide) to do this.ITO is transparent and also acts as a thin-film conductive crystal so that it doesn’t block the backlight.

The different arrangement of LCD molecules and the rapid motion change can ensure that each pixel displays the corresponding color accurately and the image changes accurately and quickly, which requires the precision of LCD molecule control.ITO film needs special treatment, just like printing the circuit on the PCB board, drawing the conductive circuit on the whole LCD board.

First, the ITO film layer needs to be deposited on the TFT glass, so that there is a smooth and uniform ITO film on the whole TFT glass. Then, using ionized water, the ITO glass is cleaned and ready for the next step.

This completes the previous Array process. It is not difficult to see from the whole process that ITO film is deposited, photoresist coated, exposed, developed, and etched on TFT glass, and finally, ITO electrode pattern designed in the early stage is formed on TFT glass to control the movement of LCD molecules on the glass. The general steps of the whole production process are not complicated, but the technical details and precautions are very complicated, so we will not introduce them here. Interested friends can consult relevant materials by themselves.

The glass that the LCD board uses makes a craft also very exquisite. (The manufacturing process flow of the LCD display screen)At present, the world’s largest LCD panel glass, mainly by the United States Corning, Japan Asahi glass manufacturers, located in the upstream of the production of LCD panel, these manufacturers have mastered the glass production technology patents. A few months ago, the earthquake caused a corning glass furnace shutdown incident, which has caused a certain impact on the LCD panel industry, you can see its position in the industry.

As mentioned earlier, the LCD panel is structured like a sandwich, with an LCD sandwiched between the lower TFT glass and the upper color filter. The terminal Cell process in LCD panel manufacturing involves the TFT glass being glued to the top and bottom of a colored filter, but this is not a simple bonding process that requires a lot of technical detail.

As you can see from the figure above, the glass is divided into 6 pieces of the same size. In other words, the LCD made from this glass is finally cut into 6 pieces, and the size of each piece is the final size. When the glass is cast, the specifications and sizes of each glass have been designed in advance.

Directional friction:Flannelette material is used to rub the surface of the layer in a specific direction so that the LCD molecules can be arranged along the friction direction of the aligned layer in the future to ensure the consistency of the arrangement of LCD molecules. After the alignment friction, there will be some contaminants such as flannelette thread, which need to be washed away through a special cleaning process.

After the TFT glass substrate is cleaned, a sealant coating is applied to allow the TFT glass substrate to be bonded to the color filter and to prevent LCD outflow.

Finally, the conductive adhesive is applied to the frame in the bonding direction of the glass of the color filter to ensure that external electrons can flow into the LCD layer. Then, according to the bonding mark on the TFT glass substrate and the color filter, two pieces of glass are bonded together, and the bonding material is solidified at high temperatures to make the upper and lower glasses fit statically.

Color filters are very important components of LCD panels. Manufacturers of color filters, like glass substrate manufacturers, are upstream of LCD panel manufacturers. Their oversupply or undersupply can directly affect the production schedule of LCD panels and indirectly affect the end market.

As can be seen from the above figure, each LCD panel is left with two edges after cutting. What is it used for? You can find the answer in the later module process

Finally, a polarizer is placed on both sides of each LCD substrate, with the horizontal polarizer facing outwards and the vertical polarizer facing inwards.

When making LCD panel, must up and down each use one, and presents the alternating direction, when has the electric field and does not have the electric field, causes the light to produce the phase difference and to present the light and dark state, uses in the display subtitle or the pattern.

The rear Module manufacturing process is mainly the integration of the drive IC pressing of the LCD substrate and the printed circuit board. This part can transmit the display signal received from the main control circuit to the drive IC to drive the LCD molecules to rotate and display the image. In addition, the backlight part will be integrated with the LCD substrate at this stage, and the complete LCD panel is completed.

Firstly, the heteroconductive adhesive is pressed on the two edges, which allows external electrons to enter the LCD substrate layer and acts as a bridge for electronic transmission

Next is the drive IC press. The main function of the drive IC is to output the required voltage to each pixel and control the degree of torsion of the LCD molecules. The drive IC is divided into two types. The source drive IC located in the X-axis is responsible for the input of data. It is characterized by high frequency and has an image function. The gate drive IC located in the Y-axis is responsible for the degree and speed of torsion of LCD molecules, which directly affects the response time of the LCD display. However, there are already many LCD panels that only have driving IC in the X-axis direction, perhaps because the Y-axis drive IC function has been integrated and simplified.

The press of the flexible circuit board can transmit data signals and act as the bridge between the external printed circuit and LCD. It can be bent and thus becomes a flexible or flexible circuit board

The manufacturing process of the LCD substrate still has a lot of details and matters needing attention, for example, rinse with clean, dry, dry, dry, ultrasonic cleaning, exposure, development and so on and so on, all have very strict technical details and requirements, so as to produce qualified eyes panel, interested friends can consult relevant technical information by a search engine.

LCD (LC) is a kind of LCD, which has the properties of light transmission and refraction of solid Crystal, as well as the flow property of Liquid. It is because of this property that it will be applied to the display field.

However, LCD does not emit light autonomously, so the display equipment using LCD as the display medium needs to be equipped with another backlight system.

First, a backplate is needed as the carrier of the light source. The common light source for LCD display equipment is CCFL cold cathode backlight, but it has started to switch to an LED backlight, but either one needs a backplate as the carrier.

CCFL backlight has been with LCD for a long time. Compared with LED backlight, CCFL backlight has many defects. However, it has gradually evolved to save 50% of the lamp and enhance the transmittance of the LCD panel, so as to achieve the purpose of energy-saving.

With the rapid development of LED in the field of lighting, the cost has been greatly reduced.LCD panels have also started to use LED as the backlight on a large scale. Currently, in order to control costs, an LED backlight is placed on the side rather than on the backplate, which can reduce the number of LED grains.

At the top of the diffusion plate, there will be 3~4 diffuser pieces, constantly uniform light to the whole surface, improve the uniformity of light, which is directly related to the LCD panel display effect. Professional LCD in order to better control the brightness uniformity of the screen, panel procurement, the later backlight control circuit, will make great efforts to ensure the quality of the panel.

Since the LCD substrate and the backlight system are not fixed by bonding, a metal or rubber frame is needed to be added to the outer layer to fix the LCD substrate and the backlight system.

After the period of the Module, the process is completed in LCM (LCDModule) factory, the core of this part of the basic does not involve the use of LCD manufacturing technology, mainly is some assembly work, so some machine panel factories such as chi mei, Korea department such as Samsung panel factory, all set with LCM factories in mainland China, Duan Mo group after the LCD panel assembly, so that we can convenient mainland area each big monitor procurement contract with LCD TV manufacturers, can reduce the human in the whole manufacturing and transportation costs.

However, neither Taiwan nor Korea has any intention to set up factories in mainland China for the LCD panel front and middle manufacturing process involving core technologies. Therefore, there is still a long way to go for China to have its own LCD panel industry.

Asia has long dominated the display module TFT LCD manufacturers’ scene. After all, most major display module manufacturers can be found in countries like China, South Korea, Japan, and India.

However, the United States doesn’t fall short of its display module manufacturers. Most American module companies may not be as well-known as their Asian counterparts, but they still produce high-quality display products for both consumers and industrial clients.

In this post, we’ll list down 7 best display module TFT LCD manufacturers in the USA. We’ll see why these companies deserve recognition as top players in the American display module industry.

STONE Technologies is a leading display module TFT LCD manufacturer in the world. The company is based in Beijing, China, and has been in operations since 2010. STONE quickly grew to become one of the most trusted display module manufacturers in 14 years.

Now, let’s move on to the list of the best display module manufacturers in the USA. These companies are your best picks if you need to find a display module TFT LCD manufacturer based in the United States:

Planar Systems is a digital display company headquartered in Hillsboro, Oregon. It specializes in providing digital display solutions such as LCD video walls and large format LCD displays.

Planar’s manufacturing facilities are located in Finland, France, and North America. Specifically, large-format displays are manufactured and assembled in Albi, France.

Another thing that makes Planar successful is its relentless focus on its customers. The company listens to what each customer requires so that they can come up with effective display solutions to address these needs.

Microtips Technology is a global electronics manufacturer based in Orlando, Florida. The company was established in 1990 and has grown into a strong fixture in the LCD industry.

What makes Microtips a great display module TFT LCD manufacturer in the USA lies in its close ties with all its customers. It does so by establishing a good rapport with its clients starting from the initial product discussions. Microtips manages to keep this exceptional rapport throughout the entire client relationship by:

Displaytech is an American display module TFT LCD manufacturer headquartered in Carlsbad, California. It was founded in 1989 and is part of several companies under the Seacomp group. The company specializes in manufacturing small to medium-sized LCD modules for various devices across all possible industries.

The company also manufactures embedded TFT devices, interface boards, and LCD development boards. Also, Displaytech offers design services for embedded products, display-based PCB assemblies, and turnkey products.

Displaytech makes it easy for clients to create their own customized LCD modules. There is a feature called Design Your Custom LCD Panel found on their site. Clients simply need to input their specifications such as their desired dimensions, LCD configuration, attributes, connector type, operating and storage temperature, and other pertinent information. Clients can then submit this form to Displaytech to get feedback, suggestions, and quotes.

Clients are assured of high-quality products from Displaytech. This is because of the numerous ISO certifications that the company holds for medical devices, automotive, and quality management. Displaytech also holds RoHS and REACH certifications.

A vast product range, good customization options, and responsive customer service – all these factors make Displaytech among the leading LCD manufacturers in the USA.

Products that Phoenix Display offers include standard, semi-custom, and fully-customized LCD modules. Specifically, these products comprise Phoenix Display’s offerings:

Phoenix Display also integrates the display design to all existing peripheral components, thereby lowering manufacturing costs, improving overall system reliability, and removes unnecessary interconnects.

Clients flock to Phoenix Display because of their decades-long experience in the display manufacturing field. The company also combines its technical expertise with its competitive manufacturing capabilities to produce the best possible LCD products for its clients.

True Vision Displays is an American display module TFT LCD manufacturing company located at Cerritos, California. It specializes in LCD display solutions for special applications in modern industries. Most of their clients come from highly-demanding fields such as aerospace, defense, medical, and financial industries.

The company produces several types of TFT LCD products. Most of them are industrial-grade and comes in various resolution types such as VGA, QVGA, XGA, and SXGA. Clients may also select product enclosures for these modules.

All products feature high-bright LCD systems that come from the company’s proprietary low-power LED backlight technology. The modules and screens also come in ruggedized forms perfect for highly-demanding outdoor industrial use.

Slow but steady growth has always been True Vision Display’s business strategy. And the company continues to be known globally through its excellent quality display products, robust research and development team, top-of-the-line manufacturing facilities, and straightforward client communication.

LXD Incorporated is among the earliest LCD manufacturers in the world. The company was founded in 1968 by James Fergason under the name International Liquid Xtal Company (ILIXCO). Its first headquarters was in Kent, Ohio. At present, LXD is based in Raleigh, North Carolina.

All of their display modules can be customized to fit any kind of specifications their clients may require. Display modules also pass through a series of reliability tests before leaving the manufacturing line. As such, LXD’s products can withstand extreme outdoor environments and operates on a wide range of temperature conditions.

Cystalfontz America is a leading supplier and manufacturer of HMI display solutions. The company is located in Spokane Valley, Washington. It has been in the display solutions business since 1998.

Crystalfontz takes pride in its ISO 9001 certification, meaning the company has effective quality control measures in place for all of its products. After all, providing high-quality products to all customers remains the company’s topmost priority. Hence, many clients from small hobbyists to large top-tier American companies partner with Crystalfontz for their display solution needs.

We’ve listed the top 7 display module TFT LCD manufacturers in the USA. All these companies may not be as well-known as other Asian manufacturers are, but they are equally competent and can deliver high-quality display products according to the client’s specifications. Contact any of them if you need a US-based manufacturer to service your display solutions needs.

We also briefly touched on STONE Technologies, another excellent LCD module manufacturer based in China. Consider partnering with STONE if you want top-of-the-line smart LCD products and you’re not necessarily looking for a US-based manufacturer. STONE will surely provide the right display solution for your needs anywhere you are on the globe.

TFT-LCD technology is based on semiconductor IC manufacturing processes, and is unique in that it uses glass substrates rather than traditional silicon wafers. For the TFT manufacturing process, thin film formation, such as CVD and PVD processes, is a very important part. The ODF process has been developed for the assembly of color filters and TFT substrates, and is used in large size LCDs.

First of all, the movement and arrangement of liquid crystal molecules need electrons to drive, so in the carrier of liquid crystal – TFT glass, there must be able to conduct the part to control the movement of liquid crystal, here will use ITO (Indium TIn Oxide, transparent conductive metal) to do this thing. ITO is transparent, also known as thin film conductive crystal so that it will not block the backlight.

The different arrangement of liquid crystal molecules and the rapid movement changes to ensure that each pixel accurately display the corresponding color, and the image changes precisely and quickly, which requires precision control of the liquid crystal molecules. ITO film requires special processing, as if printed circuitry on a PCB board, drawing conductive lines throughout the LCD board.

For array panels with back-channel etched TFT structure.The main process can be divided into 5 steps (5 lightings) according to the sequence of the layers to be made and the interrelationship between the layers.

The process includes: PECVD triple layer continuous film formation, island lithography, island dry lithography and other processes. After these processes, the final amorphous silicon island for TFT is formed on the glass substrate. The graphics obtained after the process is completed are shown in the following figure.

PVD (Physical Vapor DeposiTIon), i.e. physical vapor deposition, is an advanced surface treatment technology widely used in the international arena. Its working principle is to use gas discharge to partially dissociate the gas or evaporated material under vacuum conditions, and to deposit the evaporated material or its reactants on the substrate while the gas ions or the evaporated material ions bombard the action. At present, the most used PVD technology on the market is mainly divided into three categories: magnetron sputtering plating, multi-arc ion plating and evaporation plating.

Specific processes include: S/D metal layer sputtering into a film, S/D lithography, S/D wet lithography, channel dry lithography and other processes. After these processes, the source, drain, channel and data lines of the TFT are finally formed on the glass substrate. At this point, the TFT has been produced. The graphics obtained after the process is completed are shown in the following figure.

The process includes PECVD, photolithography, and dry lithography of vias. After these processes, the final TFT channel protective insulation layer and guide through the hole are formed on the glass substrate. The graphics obtained after the process is completed are shown in the following figure.

Color filters can be produced by various methods; photolithography is a typical method. In photolithography, color filters are produced by exposing a glass substrate coated with a photographic color resist through a photomask. The resist is hardened to form the RGB pattern of the LCD.

Pre-Tilt Angle (Pre-TIlt Angle or TBA: Tilt Bias Angle) characteristic refers to the arrangement of liquid crystal molecules on the mating film is not parallel to the film surface, but one end of the molecule in the friction direction relative to the film surface has a certain warp, the stilt angle is called pre-tilt angle. If there is no pre-tilt angle, under the external electric field, the liquid crystal molecules can stand up randomly from two directions, which will cause poor display.

When making LCD panels it is impossible to produce them one by one, which is too inefficient, so multiple pieces are processed at once and separated by cutting.

Assembly is the combination of backlight, screen, control circuit board, and touch screen and other components together to form a complete display module. Assembly is generally done by hand, and skilled workers are very important here.

There’re more than 300 procedures to produce TFT LCD. The most advanced LCD, in which the array and cell process are highly automatic. Technically, every step in the process can lead to defects, and most of the defects have been eliminated through the development of TFT LCD technology.

Point defect is a kind of defect that some point on your screen don’t display correctly. There are mainly three situations: the point keeps displaying black or whitewhen the screen is working or the point can only display a single color.

For the first two situations, that’s because the circuit on the TFT and CF controlling that defective pixel point is shorted or broken. While the third situation is caused by damaged color pixel.

In LCD, newton’s rings may occur on screen when two glass substrate haven’t been sealed well, so that one of the glass may form a convex lens and lead to light interference.

You may notice there are some screens have uneven display, which means some white area appears in dark picture or vice versa. We call this ‘mura’, a word originated from Japanese.

Mura is very common but it doesn’t affect the screen function severely, however it still bring bad look. Hence, many high end display manufacturers have their own standards of mura, and the displays without mura are of the best quality.

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.

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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 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.

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.

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.

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TFT (Thin Film Transistor) LCD (Liquid Crystal Display) dominates the world flat panel display market now. Thanks for its low cost, sharp colors, acceptable view angles, low power consumption, manufacturing friendly design, slim physical structure etc., it has driven CRT(Cathode-Ray Tube) VFD ( Vacuum Fluorescent Display) out of market, squeezed LED (Light Emitting Diode) displays only to large size display area. TFT LCD displays find wide applications in TV, computer monitors, medical, appliance, automotive, kiosk, POS terminals, low end mobile phones, marine, aerospace, industrial meters, smart homes, handheld devices, video game systems, projectors, consumer electronic products, advertisement etc. For more information about TFT displays, please visit our knowledge base.

What we are talking about TFT LCD, it is a LCD that uses TFT technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments without TFT in each pixel.

The TN type TFT LCD display is one of the oldest and lowest cost type of LCD display technology. TN TFT LCD displays have the advantages of fast response times, but its main advantages are poor color reproduction and narrow viewing angles. Colors will shift with the viewing angle. To make things worse, it has a viewing angle with gray scale inversion issue. Scientist and engineers took great effort trying to resolve the main genetic issues. Now, TN displays can look significantly better than older TN displays from decades earlier, but overall TN TFT LCD display has inferior viewing angles and poor color in comparison to other TFT LCD technologies.

IPS TFT LCD display was developed by Hitachi Ltd. in 1996 to improve on the poor viewing angle and the poor color reproduction of TN panels. Its name comes from its in-cell twist/switch difference compared with TN LCD panels.The liquid crystal molecules move parallel to the panel plane instead of perpendicular to it. This change reduces the amount of light scattering in the matrix, which gives IPS its characteristic of much improved wide viewing angles and color reproduction. But IPS TFT display has the disadvantages of lower panel transmission rate and higher production cost compared withTN type TFT displays, but these flaws can’t prevent it to be used in high end display applications which need superior color, contrast, viewing angle and crispy images.

The mono-domain VA technology is widely used for monochrome LCD displays to provide pure black background and better contrast, its uniformly alignment of the liquid crystal molecules makes the brightness changing with the viewing angle.

MVA solves this problem by causing the liquid crystal molecules to have more than one direction on a single pixel. This is done by dividing the pixel into two or four regions – called domains – and by using protrusions on the glass surfaces to pretilt the liquid crystal molecules in the different directions. In this way, the brightness of the LCD display can be made to appear uniform over a wide range of viewing angles.

This is an LCD technology derived from the IPS by Boe-Hydis of Korea. Known as fringe field switching (FFS) until 2003, advanced fringe field switching is a technology similar to IPS offering superior performance and color gamut with high luminosity. Color shift and deviation caused by light leakage is corrected by optimizing the white gamut, which also enhances white/grey reproduction. AFFS is developed by Hydis Technologies Co., Ltd, Korea (formally Hyundai Electronics, LCD Task Force).

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. (Reference)

The AFFS is similar to the IPS in concept; both align the crystal molecules in a parallel-to-substrate manner, improving viewing angles. However, the AFFS is more advanced and can better optimize power consumption. Most notably, AFFS has high transmittance, meaning that less of the light energy is absorbed within the liquid crystal layer and more is transmitted towards the surface. IPS TFT LCDs typically have lower transmittances, hence the need for the brighter backlight. This transmittance difference is rooted in the AFFS’s compact, maximized active cell space beneath each pixel.