tft display means in tamil factory

Before you get a new monition for your organization, comparing the TFT display vs IPS display is something that you should do. You would want to buy the monitor which is the most advanced in technology. Therefore, understanding which technology is good for your organization is a must. click to view the 7 Best Types Of Display Screens Technology.

Technology is changing and becoming advanced day by day. Therefore, when you are looking to get a new monitor for your organization, LCD advantages, and disadvantage,  you have to be aware of the pros and cons of that monitor. Moreover, you need to understand the type of monitor you are looking to buy.

Now, understanding the technology from the perspective of a tech-savvy person may not be the ideal thing to do unless you are that tech-savvy person. If you struggle to understand technology, then understanding it in a layman’s language would be the ideal thing to do.

That is why it is important to break it down and discuss point by point so that you can understand it in a layman’s language devoid of any technical jargon. Therefore, in this very article, let’s discuss what exactly TFT LCDs and IPS LCDs are, and what are their differences? You will also find out about their pros and cons for your organization.

The word TFT means Thin-Film-Translator. It is the technology that is used in LCD or Liquid Crystal Display. Here you should know that this type of LCD is also categorically referred to as active-matrix LCDs. It tells that these LCDs can hold back some pixels while using other pixels. So, the LCD will be using a very minimum amount of energy to function. TFT LCDs have capacitors and transistors. These are the two elements that play a key part in ensuring that the display monitor functions by using a very small amount of energy without running out of operation.

Now, it is time to take a look at its features that are tailored to improve the experience of the monitor users significantly. Here are some of the features of the TFT monitor;

The display range covers the application range of all displays from 1 inch to 40 inches as well as the large projection plane and 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 a variety of specifications of the video display models.

No radiation, no scintillation, no harm to the user’s health. In particular, the emergence of TFT LCD electronic books and periodicals will bring humans into the era of a paperless office and paperless printing, triggering a revolution in the civilized way of human learning, dissemination, and recording.

It can be normally used in the temperature range from -20℃ to +50℃, and the temperature-hardened TFT LCD can operate at low temperatures up to -80 ℃. It can not only be used as a mobile terminal display, or desktop terminal display but also can be used as a large screen projection TV, which is a full-size video display terminal with excellent performance.

The manufacturing technology has a high degree of automation and good characteristics of large-scale industrial production. TFT LCD industry technology is mature, a mass production rate of more than 90%.

It is a perfect combination of large-scale semiconductor integrated circuit technology and light source technology and has great potential for further development.

TFT LCD screen from the beginning of the use of flat glass plate, its display effect is flat right angles, let a person have a refreshing feeling. And LCDs are easier to achieve high resolution on small screens.

The word IPS refers to In-Plane-Switching which is a technology used to improve the viewing experience of the usual TFT displays. You can say that the IPS display is a more advanced version of the traditional TFT LCD module. However, the features of IPS displays are much more advanced and their applications are very much widespread. You should also know that the basic structure of the IPS LCD is the same as TFT LCD if you compare TFT LCD vs IPS.

As you already know, TFT displays do have a very quick response time which is a plus point for it. But, that does not mean IPS displays a lack of response time. In fact, the response time of an IPS LCD is much more consistent, stable, and quick than the TFT display that everyone used to use in the past. However, you will not be able to gauge the difference apparently by watching TFT and IPS displays separately. But, once you watch the screen side-by-side, the difference will become quite clear to you.

The main drawback of the TFT displays as figured above is the narrow-angle viewing experience. The monitor you buy for your organization should give you an experience of wide-angle viewing. It is very much true if you have to use the screen by staying in motion.

So, as IPS displays are an improved version of TFT displays the viewing angle of IPS LCDs is very much wide. It is a plus point in favor of IPS LCDs when you compare TFT vs IPS. With a TFT screen, you cannot watch an image from various angles without encountering halo effects, blurriness, or grayscale that will cause problems for your viewing.

It is one of the major and remarkable differences between IPS and TFT displays. So, if you don’t want to comprise on the viewing angles and want to have the best experience of viewing the screen from wide angles, the IPS display is what you want. The main reason for such a versatile and wonderful viewing angle of IPS display is the screen configuration which is widely set.

Now, when you want to achieve wide-angle viewing with your display screen, you need to make sure it has a faster level of frequency transmittance. It is where IPS displays overtake TFT displays easily in the comparison because the IPS displays have a much faster and speedier transmittance of frequencies than the TFT displays.

Now the transmittance difference between TFT displays and IPS displays would be around 1ms vs. 25ms. Now, you might think that the difference in milliseconds should not create much of a difference as far as the viewing experience is concerned. Yes, this difference cannot be gauged with a naked eye and you will find it difficult to decipher the difference.

However, when you view and an IPS display from a side-by-side angle and a TFT display from a similar angle, the difference will be quite evident in front of you. That is why those who want to avoid lagging in the screen during information sharing at a high speed; generally go for IPS displays. So, if you are someone who is looking to perform advanced applications on the monitor and want to have a wider viewing angle, then an IPS display is the perfect choice for you.

As you know, the basic structure of the IPS display and TFT displays are the same. So, it is quite obvious that an IPS display would use the same basic colors to create various shades with the pixels. However, there is a big difference with the way a TFT display would produce the colors and shade to an IPS display.

The major difference is in the way pixels get placed and the way they operate with electrodes. If you take the perspective of the TFT display, its pixels function perpendicularly once the pixels get activated with the help of the electrodes. It does help in creating sharp images.

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

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

As you already know the features of both TFT and IPS displays, it would be easier for you to understand the difference between the two screen-types. Now, let’s divide the matters into three sections and try to understand the basic differences so that you understand the two technologies in a compressive way. So, here are the difference between an IPS display and a TFT display;

Now, before starting the comparison, it is quite fair to say that both IPS and TFT displays have a wonderful and clear color display. You just cannot say that any of these two displays lag significantly when it comes to color clarity.

However, when it comes to choosing the better display on the parameter of clarity of color, then it has to be the IPS display. The reason why IPS displays tend to have better clarity of color than TFT displays is a better crystal oriental arrangement which is an important part.

That is why when you compare the IPS LCD with TFT LCD for the clarity of color, IPS LCD will get the nod because of the better and advanced technology and structure.

IPS displays have a wider aspect ratio because of the wide-set configuration. That is why it will give you a better wide-angle view when it comes to comparison between IPS and TFT displays. After a certain angle, with a TFT display, the colors will start to get a bit distorted.

But, this distortion of color is very much limited in an IPS display and you may see it very seldom after a much wider angle than the TFT displays. That is why for wide-angle viewing, TFT displays will be more preferable.

When you are comparing TFT LCD vs. IPS, energy consumption also becomes an important part of that comparison. Now, IPS technology is a much advanced technology than TFT technology. So, it is quite obvious that IPS takes a bit more energy to function than TFT.

Also, when you are using an IPS monitor, the screen will be much larger. So, as there is a need for much more energy for the IPS display to function, the battery of the device will drain faster. Furthermore, IPS panels cost way more than TFT display panels.

1. The best thing about TFT technology is it uses much less energy to function when it is used from a bigger screen. It ensures that the cost of electricity is reduced which is a wonderful plus point.

2. When it comes to visibility, the TFT technology enhances your experience wonderfully. It creates sharp images that will have no problems for older and tired eyes.

1. One of the major problems of TFT technology is that it fails to create a wider angle of view. As a result, after a certain angle, the images in a TFT screen will distort marring the overall experience of the user.

Although IPS screen technology is very good, it is still a technology based on TFT, the essence of the TFT screen. Whatever the strength of the IPS, it is a TFT-based derivative.

Finally, as you now have a proper understanding of the TFT displays vs IPS displays, it is now easier for you when it comes to choose one for your organization. Technology is advancing at a rapid pace. You should not be surprised if you see more advanced display screens in the near future. However, so far, TFT vs IPS are the two technologies that are marching ahead when it comes to making display screens.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

As you might already be aware, there’s a large variety of versatile digital display types on the market, all of which are specifically designed to perform certain functions and are suitable for numerous commercial, industrial, and personal uses. The type of digital display you choose for your company or organization depends largely on the requirements of your industry, customer-base, employees, and business practices. Unfortunately, if you happen to be technologically challenged and don’t know much about digital displays and monitors, it can be difficult to determine which features and functions would work best within your professional environment. If you have trouble deciphering the pros and cons of using TFT vs. IPS displays, here’s a little guide to help make your decision easier.

TFT stands for thin-film-transistor, which is a variant of liquid crystal display (LCD). TFTs are categorized as active matrix LCDs, which means that they can simultaneously retain certain pixels on a screen while also addressing other pixels using minimal amounts of energy. This is because TFTs consist of transistors and capacitors that respectively work to conserve as much energy as possible while still remaining in operation and rendering optimal results. TFT display technologies offer the following features, some of which are engineered to enhance overall user experience.

The bright LED backlights that are featured in TFT displays are most often used for mobile screens. These backlights offer a great deal of adaptability and can be adjusted according to the visual preferences of the user. In some cases, certain mobile devices can be set up to automatically adjust the brightness level of the screen depending on the natural or artificial lighting in any given location. This is a very handy feature for people who have difficulty learning how to adjust the settings on a device or monitor and makes for easier sunlight readability.

One of the major drawbacks of using a TFT LCD instead of an IPS is that the former doesn’t offer the same level of visibility as the latter. To get the full effect of the graphics on a TFT screen, you have to be seated right in front of the screen at all times. If you’re just using the monitor for regular web browsing, for office work, to read and answer emails, or for other everyday uses, then a TFT display will suit your needs just fine. But, if you’re using it to conduct business that requires the highest level of colour and graphic accuracy, such as completing military or naval tasks, then your best bet is to opt for an IPS screen instead.

Nonetheless, most TFT displays are still fully capable of delivering reasonably sharp images that are ideal for everyday purposes and they also have relatively short response times from your keyboard or mouse to your screen. This is because the pixel aspect ration is much narrower than its IPS counterpart and therefore, the colours aren’t as widely spread out and are formatted to fit onto the screen. Primary colours—red, yellow, and blue—are used as the basis for creating brightness and different shades, which is why there’s such a strong contrast between different aspects of every image. Computer monitors, modern-day HD TV screens, laptop monitors, mobile devices, and even tablets all utilize this technology.

IPS (in-plane-switching) technology is almost like an improvement on the traditional TFT display module in the sense that it has the same basic structure, but with slightly more enhanced features and more widespread usability. IPS LCD monitors consist of the following high-end features.

IPS screens have the capability to recognize movements and commands much faster than the traditional TFT LCD displays and as a result, their response times are infinitely faster. Of course, the human eye doesn’t notice the difference on separate occasions, but when witnessing side-by-side demonstrations, the difference is clear.

Wide-set screen configurations allow for much wider and versatile viewing angles as well. This is probably one of the most notable and bankable differences between TFT and IPS displays. With IPS displays, you can view the same image from a large variety of different angles without causing grayscale, blurriness, halo effects, or obstructing your user experience in any way. This makes IPS the perfect display option for people who rely on true-to-form and sharp colour and image contrasts in their work or daily lives.

IPS displays are designed to have higher transmittance frequencies than their TFT counterparts within a shorter period of time (precisely 1 millisecond vs. 25 milliseconds). This speed increase might seem minute or indecipherable to the naked eye, but it actually makes a huge difference in side-by-side demonstrations and observations, especially if your work depends largely on high-speed information sharing with minimal or no lagging.

Just like TFT displays, IPS displays also use primary colours to produce different shades through their pixels. The main difference in this regard is the placement of the pixels and how they interact with electrodes. In TFT displays, the pixels run perpendicular to one another when they’re activated by electrodes, which creates a pretty sharp image, but not quite as pristine or crisp as what IPS displays can achieve. IPS display technologies employ a different configuration in the sense that pixels are placed parallel to one another to reflect more light and result in a sharper, clearer, brighter, and more vibrant image. The wide-set screen also establishes a wider aspect ratio, which strengthens visibility and creates a more realistic and lasting effect.

When it comes to deciphering the differences between TFT vs. IPS display technologies and deciding which option is best for you and your business, the experts at Nauticomp Inc. can help. Not only do we offer a wide variety of computer displays, monitors, and screen types, but we also have the many years of experience in the technology industry to back up our recommendations and our knowledge. Our top-of-the-line displays and monitors are customized to suit the professional and personal needs of our clients who work across a vast array of industries. For more information on our high-end displays and monitors, please contact us.

The full form of TFT is Thin Film Transistor. It is a display screen technique used in LCD (liquid crystal display). An active component that serves as a switch for each pixel to be switched on and off is TFT. These are made up of a broad range of semiconductor compounds similar to silicon.

In TFT, one to four transistors regulate every pixel. Among all the flat-panel processes, the TFT technology is renowned for its high resolution, but it is also quite costly.

To build a display that meets high performance expectations, panel makers require a thermally and dimensionally stable glass to improve yields while achieving the desired resolution.

The display industry is continuing to move toward mid-to-large-size, immersive displays in high-performance tablets, notebooks and 8K TVs. As these trends become industry standards, the oxide market emerges as an important opportunity for enabling the next-generation of high-performance displays. These displays feature: higher resolution and faster refresh rates; enhanced circuitry integration to achieve slim bezels; and cost savings for panel makers by improving the panel aperture ratio and enabling large gen size manufacturing.

To achieve these technical requirements, new breakthroughs are needed in thin-film-transistor (TFT) technologies. Among the display industry’s current offerings, amorphous silicon TFT (a-Si TFT) maintains a leading position among all applications, while low-temperature poly-silicon TFT (LTPS) is the predominant display technology for enabling high-performance handheld displays. The key differences between a-Si and LTPS are that an a-Si TFT has a simpler process, structure, and is easier to scale up in terms of manufacturing. However, LTPS offers better TFT performance to achieve higher resolutions and lower power consumption. The drawbacks of LTPS come in size limitations and increased manufacturing costs. For these reasons, neither a-Si or LTPS can fully meet the technical requirements for this next generation of high-performance displays.

As a result, an industry need arises for a glass substrate that is precisely engineered to enable the higher pixel density of high-performance displays that panel makers require to meet consumer demand for brighter, faster, more lifelike images. To build a display that meets these performance expectations, panel makers need a thermally and dimensionally stable glass to improve yields while achieving the desired resolution.

All of these industry requirements create new process and glass composition challenges, which present the need to develop an advanced oxide TFT glass technology.

For decades, the dominant technology for flat panel displays was an amorphous silicon (a-Si) backplane. The vast majority of displays were made using a-Si backplanes due to the simplicity in manufacturing process, good economics, and scalability to larger sizes. As demands for brighter and/or higher resolution displays grew due to the introduction and proliferation of handheld mobile devices, alternative backplane technologies, such as low temperature polysilicon (LTPS), became more prevalent. LTPS is similar to a-Si, but requires higher processing temperatures and a more complicated manufacturing process. This results in advanced properties for the backplane, such as >50X higher electronic mobility. These properties allow smaller TFTs (enabling higher resolutions and brighter displays) and faster refresh rates. While clearly a superior technology to a-Si, the higher temperatures and more complex manufacturing process make LTPS considerably more expensive than a-Si. Additionally, LTPS is not easily scaled to larger sizes to enable better panel economics.

The ideal backplane technology would combine the simplicity, economics, and scalability to larger panel sizes of a-Si with the heightened performance of LTPS. This is exactly what oxide TFT technologies offer. The most commonly implemented oxide TFT technology is based on Indium-Gallium-Zinc-Oxide or “IGZO” technologies.

Though the mobility of oxide TFT is not as high as LTPS, it is an order of magnitude better than a-Si technology and capable of driving OLED displays and 8K 120Hz + LCD TVs. Additionally, the low off-current of an oxide TFT could enable low refresh frequency without flicker effects on static images (a comparison of different TFT technologies are shown in Table 1). While, like LTPS, oxide TFT backplanes have improved electrical properties relative to a-Si backplanes, oxide TFT backplanes can scale up to Gen 10.5 at reasonable costs (unlike LTPS), thereby enabling high-end, large-size LCD and OLED TVs. It is for this “just right” compromise of a-Si and LTPS properties that oxide TFT is garnering so much attention from panel makers worldwide. It offers the ability to manufacture displays far superior to a-Si at sizes and costs unachievable by LTPS.

There are two major oxide TFT processes to consider: etch-stop and back channel etch (BCE). The key difference between the processes is the use of an etch-stop layer, also known as ESL, that is required to protect the IGZO channels during the etching process.

Oxide TFT reliability was the major concern in early stage of oxide TFT development. The oxide TFT channel was usually damaged in subsequent processes, so an etch stop structure was designed to protect the oxide TFT channel. The etch-stop (ESL) oxide TFT manufacturing process begins with a bottom gate structure which is covered by a gate insulator and TFT islands. After the gate insulator (GI) layers and TFT patterning, a patterned SiO2 layer is deposited to cover the IGZO channel area in order to protect oxide TFT from following source/drain (S/D) etching. This enables better TFT reliability, and after the S/D etching, then followed by passivation, ITO layer as the Figure 1 shows. In the ESL process, temperatures may go up to 300-400°C for up to an hour or more. While these are higher temperatures than some a-Si processes, it is considerably lower than the typical LTPS processes that can exceed 500°C.

The BCE oxide TFT process (Figure 2) is very similar to the ESL oxide TFT process in the first two photo etching processes (PEP) steps. However, a high temperature (400-500°C) annealing process enhances the TFT reliability that allows the removal of the ESL. The higher temperature annealing step requires a thermally stable glass that can withstand harsh manufacturing environments and processing times relative to the conventional oxide (ESL) or a-Si processes.

To panel makers, the BCE oxide TFT process is similar to the a-Si process, which has been widely used for the past two decades. Also, there is one photo-mask process reduction compared to the ES oxide TFT process, therefore, BCE oxide TFT is becoming a mainstream process of oxide TFT manufacturing.

While the oxide TFT process has clear technical benefits for the manufacture of large and high-performance TVs, it presents a unique set of challenges for the glass substrate used in the process.

When put through a typical TFT backplane process, glass substrates will change shape or size (i.e., strain) which is called a change in total pitch (TP). One of the most important glass substrate attributes is total pitch variation (TPV), which is the deviation from predictable glass movement within a glass sheet and from sheet-to-sheet. For a glass substrate to have good TPV performance, the substrate must have the required balance of physical properties to resist the various causes of strain of the substrate: elastic distortion, stress relaxation, and compaction. These sources of strain, and the corresponding glass property that resists them, are discussed below.

In TFT processes, there are several sources of stress applied to the glass substrate, such as film stresses and gate metals. In oxide TFT, the latter is particularly significant due to the substantial thickness and covered area of the gate metal. The pitch change associated with these stresses is determined by the size of the stress, the elastic modulus of the glass, and the thickness of the substrate. Since the stresses are determined by the TFT manufacturer and the industry is continually driving to thinner and thinner substrates, the only attribute within the control of the glass manufacturer is to increase the elastic modulus to increase the stiffness of the substrate. Also, because the stresses in the TFT process can vary across a sheet or sheet-to-sheet, a higher elastic modulus will reduce the strain due to variations in the applied stresses, thereby minimizing TPV from this potential cause.

The stresses from applied films and gate metal can also contribute to the overall TPV through the relaxation of those stresses during subsequent thermal treatments. As the substrate progresses through the various steps of the TFT process, the films, gate metal, and substrate itself will all undergo stress relaxation. As the stress state of the composite changes with time and temperature, the concomitant strain will accordingly change, causing a pitch change and an increase in TPV. The glass substrate resists this stress relaxation in proportion to its effective viscosity at the process temperatures. In a-Si TFT processes, the temperatures are low enough that there is a minimal amount of stress relaxation due to the glass substrate having a relatively high viscosity at these low temperatures (the viscosity of the glass increases as the temperature decreases). In oxide TFT processing, however, temperatures are higher and, therefore, the potential for stress relaxation is greater due to the lower effective viscosity of the glass. This is particularly acute for the BCE oxide TFT process, which has process steps with temperatures in excess of 400°C. Traditional glass substrates which are sufficient for the typical a-Si applications may also be sufficient for the lower temperature ESL oxide TFT processes. However, the higher temperature BCE oxide TFT process may require a substrate with a higher effective viscosity at temperatures in the range of 400°C.

The effective viscosity of the glass substrate also plays a role in the amount of viscous relaxation the glass substrate undergoes in the TFT process due to structural relaxation of the glass itself. This is commonly referred to as “compaction” or “shrinkage” in the glass industry. Compaction is due to the evolution of the glass structure from a non-equilibrium state toward a structure closer to equilibrium with the customer process. The amount of this viscous relaxation that occurs is proportional to the degree to which the glass is out of equilibrium, and inversely proportional to the effective viscosity of the glass at the TFT process temperatures. Consequently, a higher viscosity glass is beneficial for minimizing TPV, just like in stress relaxation. In glass property terms, a higher viscosity glass is a glass with a higher “annealing point” therefore glass manufacturers will often tout the high annealing point of their glass compositions.

Glass sag typically occurs when a large sheet of glass is supported horizontally by its edges and allowed to naturally bend due to its own weight. Sag increases the process challenges on larger glass handling and uniformity in OLED evaporation process. The amount of this sag is proportional to the glass density and inversely proportional to the elastic modulus. The elastic modulus represents the glass’ capability to resist deformation in the manufacturing process, while low density allows for a light weight sheet of glass. This ratio of elastic modulus and density determines the amount of sag in the glass, with a higher ratio (higher modulus and/or lower density) leading to less sag and better performance.

Measured in microns, total thickness variation, or TTV is variation of the glass thickness over a defined area of the glass sheet. Compared to glass produced on a float platform, Corning’s proprietary fusion process creates glass with some of the industry’s lowest TTV levels.

By improving TTV, panel makers have the benefit of uniform layer thickness during deposition on the glass substrate and precision patterning in photolithography process. This is especially important from the exposure process perspective, because control of the field of focus is crucial. If the TTV of the glass is outside the field of focus in a moving window range (MWR), a crisp pattern cannot be obtained (Figure 3). Lower glass substrate TTV therefore provides a significant advantage in the precise photo-lithography steps needed for high-resolution displays.

Screen-sizes are continuing to grow and increase, creating new challenges for panel manufacturers to increase yields, maximize throughput, and reduce material costs. This makes glass utilization increasingly important to panel makers. Therefore, the glass substrate must enable efficient manufacturing and scale up to larger gen sixes (Gen 8.5 and above).

Corning’s proprietary fusion process manufactures glass panels at Gen 10.5 sizes (2940 x 3370mm), enabling higher glass utilization for larger-screen sizes. For example, one sheet of Gen 10.5 glass could create eight 65” display panels, or six 75” display panels. This enhanced glass utilization greatly reduces cost for panel makers and is key for enabling the oxide TFT market"

For oxide TFT to be used in IT or handheld products, one of the key features is a thin and light form factor. To achieve this, the display panel usually needs to be thinned down to roughly 0.15mm / 0.15mm (for the two pieces of glass in the display) using the chemical slimming process. A faster etch rate is clearly desired to enable higher throughput and lower costs but this often comes at the cost of the generation of “sludge.” Sludge can create problems in the etch vendors’ processes and end up causing more cost than the fast etch rate reduced. By using a glass that balances maximizing etch rate while minimizing sludge generation, panel makers optimize their throughput and costs.

The technology challenges and technical requirements outlined fuel an industry need for a new glass substrate with the right balance of physical properties for oxide TFT technology. For displays applications, this includes low total pitch variation, low total thickness variation, and low sag. This package of glass attributes, alongside the ability to scale-up manufacturing to large-gen sizes, will help enable the next-generation of mid-to-large-size, immersive displays in 8K TVs.

In the case of high-performance notebooks, tablets and other handhelds, fast etching and minimal sludge generation become increasingly important glass attributes for better picture quality and response times.

These applications require a shift toward oxide technology, versus the current a-Si and LTPS TFT technologies. As the push for oxide increases, new process and technical challenges emerge for panel makers. To build a display that meets these performance expectations, panel makers require a thermally and dimensionally stable glass to improve yields while achieving the desired resolution.

— TJ Kiczenski, Senior Research Associate and Business Technology Manager, High Performance Displays and PH Su, Senior Project Manager, High Performance Displays, Corning Glass Technologies.

OLED displays have become increasingly common and accessible over the past few years. While they were once reserved for premium smartphones, you’ll now find OLED displays at every smartphone price point. Not every OLED display is equal, though – differences in materials and manufacturing processes can result in varying display qualities. In that vein, let’s explore the differences between POLED vs AMOLED, and what these acronyms mean in the real world.

Before differentiating between POLED and AMOLED, it’s worth understanding the fundamentals of OLED display technology. To that end, let’s ignore the P and AM prefixes for now.

If you look at an OLED display under a microscope, you’ll see these diodes arranged in various red, green, and blue configurations in order to produce a full range of colors. OLED has a key advantage over conventional LCDs – individual light emitters can be switched completely off. This gives OLED deep blacks and an excellent contrast ratio.

Naturally, light emitters in an OLED display need a power source in order to function. Manufacturers can use either a passive wiring matrix or an active wiring matrix. Passive matrix displays provide current to an entire row of LEDs, which isn’t ideal but it is cheap. An active matrix, on the other hand, introduces a capacitor and thin-film transistor (TFT) network that allows each pixel to be driven individually. This driving matrix is part of the panel that sits on top of a base substrate.

Today, virtually all high-resolution OLED displays use active-matrix technology. This is because a passive matrix requires higher voltages the more pixels you introduce. High voltage reduces LED lifetimes, making a passive matrix OLED impractical.

AMOLED simply refers to an Active Matrix OLED panel. The AMOLED branding has become synonymous with Samsung Display’s OLED panels over the years. However, all smartphone OLED panels, including those from Samsung’s rivals like LG Display use active-matrix technology too – they just aren’t marketed as such.

In case you’re wondering what Super AMOLED means, it’s another bit of branding to indicate the presence of an embedded touch-sensitive layer. Similarly, Dynamic AMOLED refers to a display with HDR capabilities, specifically support for Samsung’s favored HDR10+ standard.

Now that we know the layered structure of an OLED display, we can move on to the plastic part. While the first wave of OLED panels was built using glass substrates, the desire for more interesting form factors has seen manufacturers use more flexible plastic components. This is where the P in POLED comes from.

Glass is fixed and rigid, while plastic substrates can be more easily formed into new shapes. This property is absolutely essential for curved screens as well as foldable devices like Samsung’s Galaxy Fold series. Working with plastics is also much more cost-effective than glass.

Manufacturers have experimented with a range of plastics for flexible displays, including polyethylene terephthalate (PET) and polyethylene naphthalate (PEN). OLED manufacturers have settled on using polyimide plastics (PI) that can better withstand high TFT manufacturing temperatures. The type of substrate and heating process used also defines the flexibility of the display.

The somewhat confusing part is that Samsung’s AMOLED displays use plastic substrates. And as the name suggests, LG Display’s POLED technology clearly uses plastic as well. In summary, it’s absolutely possible to build a plastic substrate, active-matrix OLED panel. That’s exactly what both of the big two panel manufacturers are doing when it comes to mobile displays.

Even though LG and Samsung-made OLED panels qualify as both POLED and AMOLED simultaneously, the companies aren’t exactly producing identical panels. The quality of the TFT layer and plastic compound can make a difference to display performance, as can the type of emitters and sub-pixel layout.

Different color LEDs offer different brightnesses and shelf life. Blue emitters, for example, degrade the quickest. Panel manufacturers can therefore opt to use different LED materials – such as small-molecule, polymer, or phosphorescent – to optimize their designs. This may also necessitate different subpixel layouts in order to balance the panel white color, gamut, and resolution.

Over the years, we’ve seen OLED display manufacturers converge on a set of standard parameters. For example, both LG and Samsung use a diamond PenTile sub-pixel layout for smartphone displays. This just means that both should offer similar long-term reliability.

In the past, LG used POLED displays in its own flagship smartphones like the Velvet and Wing. However, these panels fell slightly short of the competition in certain aspects like peak brightness and color gamut coverage. These shortfalls led to speculations that Samsung has a leg up over the competition, but the accuracy of these claims is anyone’s guess.

So does that mean you should avoid POLED? Not quite — it’s still fundamentally OLED technology, which offers numerous advantages over IPS LCD. Moreover, you’ll mostly find POLED displays in mid-range and budget smartphones these days, where they should have no problem matching Samsung’s own lower-end AMOLED panels. As a relatively smaller player, LG may also offer more competitive pricing as compared to Samsung.

For most consumers, the choice of POLED vs AMOLED will be of little consequence. The underlying principle – an active-matrix OLED on a flexible plastic substrate – applies equally to both, after all. Despite the different names, LG Display and Samsung aren’t worlds apart in their approach to producing OLED panels for smartphones.

Tuesday, May 18, 2010: In the display industry, liquid crystal display (LCD) and thin film transistor LCD (TFT-LCD) as components have gained footing in recent times, and have surpassed the CRT display technology to a considerable extent. LED as a component is also active displays as they emit light by themselves and convey the information to the user in the form of a number (seven segment), alphabet (alphanumeric) or picture (dotmatrix). In contrast, LCD and TFT displays require backlighting, which is mostly done with the help of LEDs, be it in mobile phones or new generation LED televisions. Large moving message displays or stadium displays use discrete LEDs placed in larger pitch arrays. Multi-coloured chips placed in these displays allow colour change through microprocessor controls.

These technological upgradations are largely driven by the environmental concerns that are driving the need for greener, efficient and advanced display systems with enhanced image quality and lower power consumption.

LCD and TFT displays as components are used in a wide spectrum of electrical and consumer electronics—from factory automation, industrial machinery, equipment manufacturing, to office and home applications. Some of their common applications are clocks, watches, calculators, telephones, television sets, computer monitors, mobile phones, handheld video games, personal digital assistants, navigation systems, projectors, etc.

The most popular form of LED display is seven segment, which comes in various sizes such as 1.27 cm (0.56 inch), 0.762 cm (0.3 inch), 1.02 cm (0.4 inch) and 2.5 cm (1.0 inch). “Red colour LED is the most economical, brightest and sought after. They are applied in telephone booth displays, digital panel meters, weighing machines and temperature controllers. These applications account for 80 per cent of the consumption,” says K Vijay Kumar Gupta, managing director, Kwality Photonics Pvt Ltd, which has been manufacturing LED displays and power LEDs (700mA) for lighting, for the last 15 years.

In India, LCD and TFT display markets are driven by importers and very few companies who manufacture LCD displays as components. Usually, LCD display components are being imported and then assembled here.

Kwality Photonics manufactures LEDs and caters mainly to high brightness and high reliability requirements. “Our customers generally demand inspection free quality of products and rely on our services rather than imports,” says Gupta.

P Hari Krishna, senior sales executive of Hyderabad based Lampex Electronics, claims to be the single largest LCD display manufacturer in India, since 1991, “We have more than two decades of manufacturing experiance and proud to state that we are the only exporter from India.” Other leading LCD manufacturers are Deepakshi Display Devices and Oriole Electronics. Leading traders in this domain include Behari Enterprises and Lappteck Marketing, who not only supply standard/monochrome LCD displays but are also trader in TFT displays. However, manufacturers are also offering customised solutions as per the needs of the customer.

The market offers three types of LCD displays that are used as components. These are monochrome, coloured and TFT. Monochrome LCD displays have been further classified into four categories such as Twisted Nematic (TN), Super Twisted Nematic (STN), Film Super Twisted Nematic (FSTN) and Color Super Twisted Nematic (CSTN). All of them vary in terms of viewing angle and temperature range, as per Nilesh Dedhia, director, Lappteck Marketing, who is the importer of powertrip, Apex, UTC, AUO, PVI, ChiMie brands of LCDs and TFTs display.

Generally, LCDs come in different forms like LCD panels, character LCDs, graphic LCDs and TFT-LCDs, varying in sizes ranging from 6 cm (2.4 inch) to 106.68 cm (42 inch). As buyers prefer LCD displays with lower power consumption, smaller sizes, sharper contrasts and larger viewing angles and with latest technology, configuration of these products change to suit their needs and to make the product, more user friendly real life display features.

“Coloured TFTs and touchscreen displays are the latest display products in the market. Recently, displays with coloured backlights have also been introduced to make LCDs aesthetically appealing,” informs Farheen Ali, director, Oriole Electronics. Her company manufactures LCD displays as a component and imports TFTs. “We have recently introduced 3.3 volt operational LCDs that consume less power compared to the traditional 5 volt LCDs,” adds Ali.

According to Sunil Khetwani, director, Behari Enterprises, a distributor of LCD displays for Winstar, Powertrip Tech and TFT displays for Prime View International, “Customers’ preferences are moving from standard LCDs to graphic LCDs and from STN to TFTs, as they have a better viewing angle and priced lower than coloured STN. Also, organic light emitting devices (OLED) are coming into prominence due to their brightness.”

According to Gupta, red, yellow and yellow-green displays, either made of obsolete gallium phosphide wafer, or aluminium gallium arsenide are also hot choice of the buyers as they give out uniform brightness across large batches. They are also made of the latest aluminium gallium indium phosphide, also known as high brightness LEDs.

From emerging segments such as avionics, instrumentation, automobile, PDAs, energy, consumer durables and defence are opening new avenues for manufactures. Their focus has been shifted from telecommunications sector to non-conventional sectors, where their products are being used in various applications.

The automobile sector has good demand for displays and customised displays are picking up slowly in this sector. Traditionally, this sector has been import driven, dominated by Japanese automobile companies. However, this trend is changing with Indian vehicle manufacturers such as Mahindra & Mahindra and Tata creating demand for customised display solutions for electronic equipment of vehicles such as LCD display for control panels.

Malakar says, “Recently, our R&D team has developed a coloured LCD display for Indian automobile company, which is 75 per cent cheaper compared to TFT. We are expecting to rollout this product by next quarter, which is presently undergoing testing.”

Agreeing to Malakar, Krishna says, “As the automobile segment has started moving from mechanical speedometer to LCD meters, we can see other segments like consumer electronics also scaling up from traditional LED displays to more energy efficient LCD displays.”

Commenting on customised display, Gupta says, “LED displays have found equilibrium with the closely competing LCD technology and have matured as products. The trend at present has shifted towards multi digit customised LED displays, thanks to market players aiming at large volumes in shorter product cycle time.”

While displays are being customised, technological innovations also take place as customers demand advance technology. Monochrome LCD displays and graphical displays have been innovated with high temperature range.

“Manufacturers of LCD displays are moving from standard LCDs to affordable coloured LCDs. Innovation has also taken place to compress more pixels in TFTs to have better resolution. For rough environmental conditions and temperatures, ratings have also been increased,” says Dedhia.

LED displays have also seen innovations. They are now found in SMD versions too. The chip on board (COB) versions are also manufactured for compact applications. Highly integrated multifunction indicator displays are also being made for DVD players, music systems, AC consoles and microwave ovens. These are used for their dynamic changing colours as they enhance aesthetics.

“Pointing out that not many new standards are likely to emerge from the LED display line,” Gupta says. Most of the research activities are directed towards lighting LEDs and In GaN materials. Research is also going on in the field of high efficiency emitter in green LED with 500-600 nm spectrum.

LCD is a key component in any electronics product. Failure of LCD means failure of the product. Therefore, timely service support for products using them is very critical. Importers like Lappteck Marketing offers one year warranty on its products. For faulty products, repair or replacement facility is also available. Malakar says, “We offer end-to-end support, from designing and conceptualising to technical support, to our customers.” Lampex offers complete turnkey solutions and complete support and warranty for LCD displays.

Oriole provides interfacing schematics and test code for all displays. “We conduct half day or one day training sessions for our customers to familiarise them with the products. We also provide test kits and evaluation boards or sometimes undertake entire LCD interfacing to hasten the customers development lifecycle,” adds Ali.

Indian buyers seek the best products at lowest price. But apart from effective pricing, they need the right technical support and customised solution as per their requirement.

According to Gajandhra, proprietor, Rotex Electronix, TFT-LCDs and touchscreens are gaining popularity and aesthetics is playing a key role in their sales. Buyers of LCD components prefer sleeker screens in place of bulky cathode ray tube (CRT).

As Ali puts it, “There are many low cost displays available in the market. However, as the technology is changing fast, they become obsolete and their redesigning becomes extremely cumbersome as we lose their track in the market after a certain time. Buyers should try to avoid such products.”

LCD and TFT displays must be selected carefully depending on the kind of information to be displayed and the price of the product in which they are to be used. Apart from these, LED backlight brightness, technical support and long term availability of the display are other important factors that must be considered, informs Ali.

According to Malakar, LCD displays need several rounds of designing and redesigning, thus customers should buy products from creditable manufacturers. By buying from importers customers can only get price advantage but no technical service support.

“Quality of components, software capability, future upgradation, after sales support, technical expertise and track record of the traders should be checked. Price is not everything. Reliability and availability of high quality should be the most important factors for the buyers,” says Malakar.

The most desired parameters in LED displays are uniform brightness among all the digits within each batch. This can be achieved by specifying and procuring specially probed and sorted chips for intensity, wavelength and forward voltage, although these steps add to the cost. “This way Kwality predicts the brightness and calibrates it as per customers’ application requirements. Buyers of Chinese brands do not have this advantage,” says Gupta.

Finally, while buying displays, the most importan