are all lcd monitors also tft brands
A TFT monitor uses thin-film transistor technology in an LCD display. LCD monitors, also called flat panel displays, are replacing the old-style cathode ray tubes (CRTs) in both televisions and computer displays. Nearly all LCD monitors today use TFT technology.
The benefit of thin-film transistor technology is the separate, tiny transistor for each pixel on the display. Because each transistor is so small, the amount of charge needed to control it is also small. This allows the screen to refresh very quickly, as the image is re-painted or refreshed several times per second.
Prior to TFT, passive matrix LCD displays could not keep up with fast moving images. A mouse dragged across the screen, for example, from point A to point B, would disappear between the two points. A TFT monitor can track the mouse, resulting in a display that can be used for video, gaming, and all forms of multimedia.
A 17-inch TFT monitor has about 1.3 million pixels and 1.3 million transistors. That leaves a significant chance for a malfunctioning transistor or two on the panel, and "dead pixels" are not uncommon. A dead pixel is a pixel whose transistor has failed, thereby creating no display image so on a solid black background, for example, dead pixels will stand out as tiny dots of red, white, or blue. Most manufacturers will not replace a monitor that has fewer than 11 dead pixels. Many don"t have any dead pixels, although even in those that do, they are not really noticeable unless they are located in a critical position on the screen.
There are only a handful of TFT factories that turn out panels for all brands of monitors. Since there is a given failure rate — considering how many transistors are on each panel — only so many of the displays come out bearing no dead pixels. A certain percentage have some, but not an unreasonable number, and other panels are unusable. The panels that have some dead pixels are often sold to be used in discount models. Consumers, therefore, should read online feedback from buyers to get an idea of the quality of particular brands. By scanning the reviews for several brands, it is easy to get a feel for which models have consistently good panels that rarely bear dead pixels.
A good TFT monitor delivers crisp text, vibrant color, and an improved response time for multimedia applications. People who are interested in gaming, video editing, or other multimedia applications should look for a monitor with a response rate of 16 ms or less.
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.
These products are all widely used in various industries such as in medicine, home security, automotive, energy field solar charging, and domestic equipment use.
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.
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.
Microtips also provides value-added services to all its clients. The company’s Electronic Manufacturing Services team gives product suggestions and shares insights on how clients can successfully manage their projects.
Taiwan and Mainland China are two Asian countries where Microtips set up their manufacturing plants. The factories boast of modern equipment, high-quality raw materials, and stringent quality control measures. Microtips even earned ISO9001 and ISO14001 certifications for excellent quality management.
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.
LXD has research centers and factories in both the United States and China. The US-based headquarters feature a massive 30,000 square feet of manufacturing and research development centers. Meanwhile, LXD’s Chinese facilities feature a large 5,000 square meters of cleanrooms for manufacturing modular and glass products.
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.
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.
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.
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.
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.
In market, LCD means passive matrix LCDs which increase TN (Twisted Nematic), STN (Super Twisted Nematic), or FSTN (Film Compensated STN) LCD Displays. It is a kind of earliest and lowest cost display technology.
LCD screens are still found in the market of low cost watches, calculators, clocks, utility meters etc. because of its advantages of low cost, fast response time (speed), wide temperature range, low power consumption, sunlight readable with transflective or reflective polarizers etc. Most of them are monochrome LCD display and belong to passive-matrix LCDs.
TFT LCDs have capacitors and transistors. These are the two elements that play a key part in ensuring that the TFT display monitor functions by using a very small amount of energy without running out of operation.
Normally, we say TFT LCD panels or TFT screens, we mean they are TN (Twisted Nematic) Type TFT displays or TN panels, or TN screen technology. TFT is active-matrix LCDs, it is a kind of LCD technologies.
TFT has wider viewing angles, better contrast ratio than TN displays. TFT display technologies have been widely used for computer monitors, laptops, medical monitors, industrial monitors, ATM, point of sales etc.
Actually, IPS technology is a kind of TFT display with thin film transistors for individual pixels. But IPS displays have superior high contrast, wide viewing angle, color reproduction, image quality etc. IPS screens have been found in high-end applications, like Apple iPhones, iPads, Samsung mobile phones, more expensive LCD monitors etc.
Both TFT LCD displays and IPS LCD displays are active matrix displays, neither of them can produce color, there is a layer of RGB (red, green, blue) color filter in each LCD pixels to make LCD showing colors. If you use a magnifier to see your monitor, you will see RGB color. With switch on/off and different level of brightness RGB, we can get many colors.
Neither of them can’t release color themselves, they have relied on extra light source in order to display. LED backlights are usually be together with them in the display modules as the light sources. Besides, both TFT screens and IPS screens are transmissive, it will need more power or more expensive than passive matrix LCD screens to be seen under sunlight. IPS screens transmittance is lower than TFT screens, more power is needed for IPS LCD display.
Have you ever wonder where TFT derive from? Why is TFT referred to as LCD? The phenomenon started in early days, when bulky CRT displays were thing of the past and LCD was its replacement, but as time progresses, there were still room for improvement, which leads to the birth of TFT’s.
TFT is a variant of an LCD which uses thin film transistor technology to improve an image quality, while an LCD is class of displays that uses modulating properties of liquid crystals to form what we call an LCD (liquid crystals display) which in fact does not emits light directly.
Even though LCDs were very energy efficient, light weight and thin in nature, LCD were falling behind to the CRT display, which then leads to a change in LCD manufacturing, where performance became a big problem.
For example, having a 2001 Mustang vs a 2014 Mustang, the dimensions and engine of the 2014 has been redesign for performance reasons, not mentioning user friendly, so does the LCD to TFT.
As the birth of TFT, the elements are deposited directly on the glass substrate which in fact the main reason for the switch was because TFTs are easier to produce, better performance in terms of adjusting the pixels within the display to get better quality.
LCDs became ineffective over a period of time, almost all aspect of watching a TV, playing video games or using a handheld device to surf the net became daunting, this phenomenon is known as high response time with low motion rate.
Another problem with LCD was crosstalking, in terms of pixelating, this happens when signals of adjacent pixels affects operations or gives an undesired effect to the other pixel.
As TFT’s become very popular throughout the century due to its elaborate low charge associate and outstanding response time, LCDs became a thing of the past, and TFT became the predominant technology with their wider viewing angles and better quality this technology will be around for a long time.
TFT stands for thin-film transistor, which means that each pixel in the device has a thin-film transistor attached to it. Transistors are activated by electrical currents that make contact with the pixels to produce impeccable image quality on the screen. Here are some important features of TFT displays.Excellent Colour Display.Top notch colour contrast, clarity, and brightness settings that can be adjusted to accommodate specific application requirements.Extended Half-Life.TFT displays boast a much higher half-life than their LED counterparts and they also come in a variety of size configurations that can impact the device’s half-life depending on usage and other factors.TFT displays can have either resistive or capacitive touch panels.Resistive is usually the standard because it comes at a lower price point, but you can also opt for capacitive which is compatible with most modern smartphones and other devices.TFT displays offer exceptional aspect ratio control.Aspect ratio control contributes to better image clarity and quality by mapping out the number of pixels that are in the source image compared to the resolution pixels on the screen.Monitor ghosting doesn’t occur on TFT displays.This is when a moving image or object has blurry pixels following it across the screen, resembling a ghost.
TFT displays are incredibly versatile.The offer a number of different interface options that are compatible with various devices and accommodate the technical capabilities of all users.
There are two main types of TFT LCD displays:· Twisted nematic TFT LCDs are an older model. They have limited colour options and use 6 bits per each blue, red, and green channel.
In-plane switching TFT LCDs are a newer model. Originally introduced in the 1990s by Hitachi, in-plane switching TFT LCDs consist of moving liquid pixels that move in contrast or opposite the plane of the display, rather than alongside it.
The type of TFT LCD monitor or industrial display you choose to purchase will depend on the specifications of your application or project. Here are a few important factors to consider when selecting an appropriate TFT LCD display technology:Life expectancy/battery life.Depending on the length of ongoing use and the duration of your project, you’re going to want to choose a device that can last a long time while maintaining quality usage.
Touch type and accuracy.What type of activities are you planning on using your device for? If it’s for extended outdoor use, then you should go with projected capacitive touch as this is more precise and accurate. Touch accuracy is important for industrial and commercial applications.
Image clarity.Some TFT displays feature infrared touchscreens, while others are layered. The former is preferable, especially in poor lighting conditions or for outdoor and industrial applications, because there’s no overlay and therefore no obstructions to light emittance.
The environmental conditions make a difference in operation and image clarity. When choosing a TFT for outdoor or industrial applications, be sure to choose one that can withstand various environmental elements like dust, wind, moisture, dirt, and even sunlight.
As a leading manufacturer and distributor of high-quality digital displays in North America, Nauticomp Inc. can provide custom TFT LCD monitor solutions that are suitable for a multitude of industrial and commercial indoor and outdoor applications. Contact us today to learn more.
Many companies have adopted Thin Film Transistor (TFT) technology to improve colour screens. In a TFT screen, also known as active matrix, an extra matrix of transistors is connected to the LCD panel – one transistor for each colour (RGB) of each pixel. These transistors drive the pixels, eliminating at a stroke the problems of ghosting and slow response speed that afflict non-TFT LCDs.
When introduced, TFTs offered screen response times of the order of 25ms, contrast ratios in the region of 200:1 to 400:1 and brightness values between 200 and 250cd/m2 (candela per square metre). At time of writing an affordable 19 LCD TFT monitor should give response time sub 5ms and brightness in the region of 300cd/m2.
The liquid crystal elements of each pixel are arranged so that in their normal state (with no voltage applied) the light coming through the passive filter is polarised so as to pass through the screen. When a voltage is applied across the liquid crystal elements they twist by up to ninety degrees in proportion to the voltage, changing their polarisation and thereby blocking the light’s path. The transistors control the degree of twist and hence the intensity of the red, green and blue elements of each pixel forming the image on the display.
TFT screens can be made much thinner than LCDs, making them lighter, and refresh rates now approach those of CRTs as the current runs about ten times faster than on a DSTN screen. VGA screens need 921,000 transistors (640x480x3), while a resolution of 1024×768 needs 2,359,296 and each has to be perfect. The complete matrix of transistors has to be produced on a single, expensive silicon wafer and the presence of more than a couple of impurities means that the whole wafer must be discarded. This leads to a high wastage rate and is the main reason for the high price of TFT displays. It’s also the reason why in any TFT display there are liable to be a couple of defective pixels where the transistors have failed.
The former is the more common and is the result of a transistor occasionally shorting on, resulting in a permanently turned-on (red, green or blue) pixel. Unfortunately, fixing the transistor itself is not possible after assembly. It is possible to disable an offending transistor using a laser. However, this just creates black dots which would appear on a white background. Permanently turned on pixels are a fairly common occurrence in LCD manufacturing and LCD manufacturers set limits – based on user feedback and manufacturing cost data – as to how many defective pixels are acceptable for a given LCD panel. The goal in setting these limits is to maintain reasonable product pricing while minimising the degree of user distraction from defective pixels. For example, a 1024×768 native resolution panel – containing a total of 2,359,296 (1024x768x3) pixels – which has 20 defective pixels, would have a pixel defect rate of (20/2,359,296)*100 = 0.0008%.
Clearly, TFT panels have undergone significant evolution since the days of the early twisted nematic (TN) technology based panels. On the next few pages we’ll look at how IPS (In-Plane Switching), VA (Vertical Alignment) and MVA (Multi-domain Vertical Alignment) have been developed by manufacturers to enhance the performance of TFT LCD monitors.
Focus Displays offers a wide range of standard full color TFT displays. 64 million unique colors, high brightness, sharp contrast, -30C operating temperature, and fast response time are all good descriptions of a TFT display. This is why TFT technology is one of the most popular choices for a new product.
Thin Film Transistor (TFT) display technology can be seen in products such as laptop computers, cell phones, tablets, digital cameras, and many other products that require color. TFT’s are active matrix displays which offers exceptional viewing experiences especially when compared to other passive matrix technologies. The clarity on TFT displays is outstanding; and they possess a longer half-life than some types of OLEDs and range in sizes from less than an inch to over 15 inches.
Cold-Cathode Fluorescent Lamp (CCFL) is an AC driven backlight that requires an inverter to convert DC to AC. The AC signal and inverter may generate EMI (Electromagnetic interference) and arcing; Arcing must be eliminated for Intrinsically Safe products.
CCFL’s are still available, but are becoming a legacy (obsolete) component. TFT displays equipped with a CCFL require higher MOQs (Minimum Order Quantities) than displays with LED backlights.
Red, Green and Blue (RGB) backlights are built with either a single LED that produces red, green and blue colors or with three separate Red, Green or Blue LEDs.
Backlight brightness (Luminance) is measured in nits. A nit being the amount of light that one candle delivers in a 1 square meter box. The intensity of the LED backlight can be critical when operating in low light or in direct sun light and is usually controlled by adjusting the DC voltage. In many applications this is accomplished through pulse-width modulation (PWM)
The majority of TFT displays contain a touch panel, or touch screen. The touch panel is a touch-sensitive transparent overlay mounted on the front of the display glass. Allowing for interaction between the user and the LCD display.
Some touch panels require an independent driver IC; which can be included in the TFT display module or placed on the customer’s Printed Circuit Board (PCB). Touch screens make use of coordinate systems to locate where the user touched the screen.
Resistive touch panels are the lowest cost option and are standard equipment on many TFT modules. They are more common on smaller TFT displays, but can still be incorporated on larger modules.
Resistive touch panels are constructed using flexible materials with an air gap between and are coated with a resistive layer. When an object applies pressure to the top layer, it makes contact with microdots located on the bottom layer. This allows the touch screen to find the location of the touch using X and Y coordinates.
Custom resistive touch screens are an option if the customer requires a seal or gasket to be in contact with the glass and not in contact with the touch panel.
Resistive touch panels allow a single touch, although advances in new resistive technology will allow multi-touch operation in the near future. One main advantage of a resistive touch screen is the ability to be activated by the touch of any material. This includes a range of items from a bare finger, to a pencil, to even the edge of a credit card; regardless of its composition.
They also have the added advantage of operating in a wide temperature range and environments, including anything from the arctic cold of Alaska to the extreme heat of Death Valley.
Capacitive touch panels have become popular with such software as Windows 8®, Android® and Apple®. Additionally it is used in products such as cell phones and tablets, where multi-touch and zoom capabilities are important.
Contrast ratio, or static contrast ratio, is one way to measure the sharpness of the TFT LCD display. This ratio is the difference between the darkest black and the brightest white the display is able to produce. The higher the number on the left, the sharper the image. A typical contrast ratio for TFT may be 300:1. This number ratio means that the white is 300 times brighter than the black.
TFT LCD displays are measured in inches; this is the measurement of the diagonal distance across the glass. Common TFT sizes include: 1.77”, 2.4”, 2.8”, 3”, 4.3”, 5”, 5.7”, 5.8”, 7”, 10.2”, 12.1 and 15”.
As a general rule, the larger the size of the glass the higher the cost of the display, but there are exceptions to this rule. A larger display may be less expensive than a smaller display if the manufacture produces higher quantities of the larger displays. When selecting your color display, be sure to ask what the cost is for one size smaller and one size larger. It may be worth modifying your design requirements.
TFT resolution is the number of dots or pixels the display contains. It is measured by the number of dots along the horizontal (X axis) and the dots along the vertical (Y axis).
The higher the resolution, the more dots per square inch (DPI), the sharper the display will look. A higher resolution results in a higher cost. One reason for the increase in cost is that more driver chips are necessary to drive each segment.
Certain combinations of width and height are standardized and typically given a name and a letter representation that is descriptive of its dimensions. Popular names given to the TFT LCD displays resolution include:
Transmissive displays must have the backlight on at all times to read the display, but are not the best option in direct sunlight unless the backlight is 750 Nits or higher. A majority of TFT displays are Transmissive, but they will require more power to operate with a brighter backlight.
Transflective displays are readable with the backlight off provided there is enough ambient light. Transflective displays are more expensive than Transmissive also there may be a larger MOQ for Transflective. However, Transflective displays are the best option for direct sunlight.
Drivers update and refresh the pixels (Picture Elements) of a display. Each driver is assigned a set number of pixels. If there are more pixels than a single driver can handle, then an additional drivers are added.
A primary job of the driver is to refresh each pixel. In passive TFT displays, the pixel is refreshed and then allowed to slowly fade (aka decay) until refreshed again. The higher the refresh frequency, the sharper the displays contrast.
The TFT display (minus touch screen/backlight) alone will contain one controller/driver combination. These are built into the display so the design engineer does not need to locate the correct hardware.
If you do not see a Thin Film Transistor (TFT) Display module that meets your specifications, or you need a replacement TFT, we can build a custom TFT displays to meet your requirements. Custom TFTs require a one-time tooling fee and may require higher MOQs.
Ready to order samples for your TFT design? Contact one of our US-based technical support people today concerning your design requirements. Note: We can provide smaller quantities for samples and prototyping.
While there are many different manufacturers of LCD monitors, the panels themselves are actually only manufactured by a relatively small selection of companies. The three main manufacturers tend to be Samsung, AU Optronics and LG.Display (previously LG.Philips), but there are also a range of other companies like Innolux and CPT which are used widely in the market. Below is a database of all the current panel modules manufactured in each size. These show the module number along with important information including panel technology and a detailed spec. This should provide a detailed list of panels used, and can give you some insight into what is used in any given LCD display.
Note:These are taken from manufacturer product documentation and panel resource websites. Specs are up to date to the best of our knowledge, and new panels will be added as and when they are produced. Where gaps are present, the detail is unknown or not listed in documentation. The colour depth specs are taken from the manufacturer, and so where they specify FRC and 8-bit etc, this is their listing. Absence of such in the table below does not necessarily mean they aren’t using FRC etc, just that this is how the manufacturer lists the spec on their site.
Get rich colors, detailed images, and bright graphics from an LCD with a TFT screen. Our standard Displaytech TFT screens start at 1” through 7” in diagonal size and have a variety of display resolutions to select from. Displaytech TFT displays meet the needs for products within industrial, medical, and consumer applications.
TFT displays are LCD modules with thin-film transistor technology. The TFT display technology offers full color RGB showcasing a range of colors and hues. These liquid crystal display panels are available with touchscreen capabilities, wide viewing angles, and bright luminance for high contrast.
Our TFT displays have LVDS, RGB, SPI, and MCU interfaces. All Displaytech TFT LCD modules include an LED backlight, FPC, driver ICs, and the LCD panel.
We offer resistive and capacitive touch screens for our 2.8” and larger TFT modules. Our TFT panels have a wide operating temperature range to suit a variety of environments. All Displaytech LCDs are RoHS compliant.
We also offer semi-customization to our standard TFT screens. This is a cost-optimized solution to make a standard product better suit your application’s needs compared to selecting a fully custom TFT LCD. Customizations can focus on cover glass, mounting / enclosures, and more - contact us to discuss your semi-custom TFT solution.
... panel mount monitors in metal front. We develop monitors able to resist to most of the hardest environments: dusts, projection, humidity, temperature variation …
... Industrial Monitor with a 19"LCD TFT display, manufactured by IPO Technologie. This screen is compatible with all PCs, and is made out of heavy-duty metal. It uses a fanless cooling system ...
... 17" touch monitor features 1280x 1024 resolutions which help you to have the photo images more clear. Furthermore the 4:3 ratio TFT is easy to work with your current applications.
... glass, with excellent touch sensitive. LCD7 with 7" TFT(1024 x 600, max support resolution 1920 x1080), furthermore support headphone Drives, 46mW.
M-series industrial true flat touch monitors have two segments: small size from 7”, 8”, 10.1”, to 10.4”, and large size define from 15”, 17”, to 18.5”. All of M-series industrial monitors apply standardized ...
TFT/PANxxxIS are industrial panel displays in the range of 10.4 inches to 19 inches. These are fan-less devices and come with infrared touch, ideal for industrial uses. The scratch-proof resistant makes it even more durable ...
Our original UReady family of next generation TFT Displays for 1U and 2U racks, along with monitors in a range of sizes, all driven by our embedded ...
... Touch monitor product. The design uses a widescreen 21.5" FHD LCD screen and multi-point (10- points) projective capacitive touch screen, and it can fulfill front panel NEMA/IP65 dust-proof and water-proof ...
All-in-one stainless steel HMI with integrated touch or membrane keyboard for operation in cleanroom. Very easy to clean and disinfect due to smooth sides, rounded edges and a flat, smooth front. Crafted from AISI 316L stainless steel ...
Industrial monitor for panel mounting with 12-24 VDC or 110-230 VAC, 18.5” TFT size in 1366x768 resolution. The PMG118 main feature is an high brightness, an wide angle and the opportunity to link the ...
Panox Display provides a customized cover glass/touch panel service. We supply cover glass from Gorilla, AGC, and Panda, which all have excellent optical performance. We also supply driver ICs from Goodix and Focaltech.
If your applications are directly connected to a PC, a cellphone, or Raspberry Pi, and you have enough space to insert a board to input video, Panox Display can provide customized Controller/Driver boards with input connections for VGA, HDMI, DVI, DP, Type-C video input, MIPI, RGB, LVDS, and eDP.
The functions of our boards include, but are not limited to, adjustment of brightness, sound output, touch interface, extra data transmission, and gyroscope.
Let us start with the basics first; refresh the knowledge about TN and LCD displays in general, later we will talk about TFTs (Thin Film Transistors), how they differ from regular monochrome LCD displays. Then we will go on to the ghosting effect, so we will not only discuss the technology behind the construction of the TFT, but also some phenomena, like the ghosting effect, or grayscale inversion, that are important to understand when using an LCD TFT display.
Next, we will look at different technologies of the TFT LCD displays like TN, IPS, VA, and of course about transmissive and transflective LCD displays, because TFT displays also can be transmissive and transflective. In the last part we will talk about backlight.
Let us start with a short review of the most basic liquid crystal cell, which is the TN (twisted nematic) display. On the picture above, we can see that the light can be transmit through the cell or blocked by the liquid crystal cell using voltage. If you want to learn more about monochrome LCD displays and the basics of LCD displays, follow this link.
What is a TFT LCD display and how it is different from a monochrome LCD display? TFT is called an active display. Active, means we have one or more transistors in every cell, in every pixel and in every subpixel. TFT stands for Thin Film Transistor, transistors that are very small and very thin and are built into the pixel, so they are not somewhere outside in a controller, but they are in the pixel itself. For example, in a 55-inch TV set, the TFT display contains millions of transistors in the pixels. We do not see them, because they are very small and hidden, if we zoom in, however, we can see them in every corner of each pixel, like on the picture below.
On the picture above we can see subpixels, that are basic RGB (Red, Green, Blue) colors and a black part, with the transistors and electronic circuits. We just need to know that we have pixels, and subpixels, and each subpixel has transistors. This makes the display active, and thus is called the TFT display. TFT displays are usually color displays, but there are also monochrome TFT displays, that are active, and have transistors, but have no colors. The colors in the TFT LCD display are typically added by color filters on each subpixel. Usually the filters are RGB, but we also have RGBW (Red, Green, Blue, White) LCD displays with added subpixels without the filter (White) to make the display brighter.
What is interesting, the white part of the RGB and RGBW screen will look exactly the same from a distance, because the lights are mixed and generate white light, but when we come closer to the screen, we will not see white light at all.
Going a little bit deeper, into the TFT cell, there is a part inside well known to us from the monochrome LCD display Riverdi University lecture. We have a cell, liquid crystal, polarizers, an ITO (Indium Tin Oxide) layer for the electrodes, and additionally an electronic circuit. Usually, the electronic circuit consists of one transistor and some capacitors to sustain the pixel state when we switch the pixel OFF and ON. In a TFT LCD display the pixels are much more complicated because apart from building the liquid crystal part, we also need to build an electronic part.
That is why TFT LCD display technologies are very expensive to manufacture. If you are familiar with electronics, you know that the transistor is a kind of switch, and it allows us to switch the pixel ON and OFF. Because it is built into the pixel itself, it can be done very quickly and be very well controlled. We can control the exact state of every pixel not only the ON and OFF states, but also all the states in between. We can switch the light of the cells ON and OFF in several steps. Usually for TFT LCD displays it will be 8-bit steps per color, so we have 256 steps of brightness for every color, and every subpixel. Because we have three subpixels, we have a 24-bit color range, that means over 16 million combinations, we can, at least theoretically, show on our TFT LCD display over 16 million distinct colors using RGB pixels.
Now that we know how the TFT LCD display works, we can now learn some practical things one of which is LCD TFT ghosting. We know how the image is created, but what happens when we have the image on the screen for a prolonged time, and how to prevent it. In LCD displays we have something called LCD ghosting. We do not see it very often, but in some displays this phenomenon still exists.
If some elements of the picture i.e., your company logo is in the same place of the screen for a long period of time, for couple of weeks, months or a year, the crystals will memorize the state and later, when we change the image, we may see some ghosting of those elements. It really depends on many conditions like temperature and even the screen image that we display on the screen for longer periods of time. When you build your application, you can use some techniques to avoid it, like very rapid contrast change and of course to avoid the positioning the same image in the same position for a longer time.
You may have seen this phenomenon already as it is common in every display technology, and even companies like Apple put information on their websites, that users may encounter this phenomenon and how to fix it. It is called image ghosting or image persistence, and even Retina displays are not free of it.
Another issue present in TFT displays, especially TN LCD displays, is grayscale inversion. This is a phenomenon that changes the colors of the screen according to the viewing angle, and it is only one-sided. When buying a TFT LCD display, first we need to check what kind of technology it is. If it is an IPS display, like the Riverdi IPS display line, then we do not need to worry about the grayscale inversion because all the viewing angles will be the same and all of them will be very high, like 80, 85, or 89 degrees. But if you buy a more common or older display technology type, like the TN (twisted nematic) display, you need to think where it will be used, because one viewing angle will be out. It may be sometimes confusing, and you need to be careful as most factories define viewing direction of the screen and mistake this with the greyscale inversion side.
On the picture above, you can see further explanation of the grayscale inversion from Wikipedia. It says that some early panels and also nowadays TN displays, have grayscale inversion not necessary up-down, but it can be any angle, you need to check in the datasheet. The reason technologies like IPS (In-Plane Switching), used in the latest Riverdi displays, or VA, were developed, was to avoid this phenomenon. Also, we do not want to brag, but the Wikipedia definition references our website.
We know already that TN (twisted nematic) displays, suffer from grayscale inversion, which means the display has one viewing side, where the image color suddenly changes. It is tricky, and you need to be careful. On the picture above there is a part of the LCD TFT specification of a TN (twisted nematic) display, that has grayscale inversion, and if we go to this table, we can see the viewing angles. They are defined at 70, 70, 60 and 70 degrees, that is the maximum viewing angle, at which the user can see the image. Normally we may think that 70 degrees is better, so we will choose left and right side to be 70 degrees, and then up and down, and if we do not know the grayscale inversion phenomena, we may put our user on the bottom side which is also 70 degrees. The viewing direction will be then like a 6 o’clock direction, so we call it a 6 o’clock display. But you need to be careful! Looking at the specification, we can see that this display was defined as a 12 o’clock display, so it is best for it to be seen from a 12 o’clock direction. But we can find that the 12 o’clock has a lower viewing angle – 60 degrees. What does it mean? It means that on this side there will be no grayscale inversion. If we go to 40, 50, 60 degrees and even a little bit more, probably we will still see the image properly. Maybe with lower contrast, but the colors will not change. If we go from the bottom, from a 6 o’clock direction where we have the grayscale inversion, after 70 degrees or lower we will see a sudden color change, and of course this is something we want to avoid.
To summarize, when you buy older technology like TN and displays, which are still very popular, and Riverdi is selling them as well, you need to be careful where you put your display. If it is a handheld device, you will see the display from the bottom, but if you put it on a wall, you will see the display from the top, so you need to define it during the design phase, because later it is usually impossible or expensive to change the direction.
We will talk now about the other TFT technologies, that allow us to have wider viewing angles and more vivid colors. The most basic technology for monochrome and TFT LCD displays is twisted nematic (TN). As we already know, this kind of displays have a problem with grayscale inversion. On one side we have a higher retardation and will not get a clear image. That is why we have other technologies like VA (Vertical Alignment), where the liquid crystal is differently organized, and another variation of the TFT technology – IPS which is In-Plane Switching. The VA and IPS LCD displays do not have a problem with the viewing angles, you can see a clear image from all sides.
Nowadays all TV sets, tablets and of course mobile phones are IPS or VA. You can turn them around and see the image clear from all sides. But, for monitor applications the TN technology is still widely used, because the monitor usually is in front of you and most of the time you look directly at it, from top, left or right side, but very rarely from the bottom, so the grayscale inversion viewing angle can be placed there. This technology still is very practical because it is affordable and has some advantages for gamers because it is very fast.
Apart from the different organization of the liquid crystals, we also organize subpixels a little bit differently in a VA and IPS LCD displays. When we look closer at the TN display, we will just see the subpixels with color filters. If we look at the VA or IPS display they will have subpixels of subpixels. The subpixels are divided into smaller parts. In this way we can achieve even wider viewing angles and better colors for the user, but of course, it is more complicated and more expensive to do.
The picture above presents the TN display and grayscale inversion. For IPS or VA technology there is no such effect. The picture will be the same from all the sides we look so these technologies are popular where we need wide viewing angles, and TN is popular where we don’t need that, like in monitors. Other advantages of IPS LCD displays are they give accurate colors, and wide viewing angles. What is also important in practice, in our projects, is that the IPS LCD displays are less susceptible to mechanical force. When we apply mechanical force to the screen, and have an optically bonded touch screen, we push the display as well as squeeze the cells. When we have a TN display, every push on the cell changes the image suddenly, with the IPS LCD displays with in-plane switching, different liquid crystals organization, this effect is lesser. It is not completely removed but it is much less distinct. That is another reason IPS displays are very popular for smartphones, tablets, when we have the touchscreens usually optically bonded.
If we wanted to talk about disadvantages, there is a question mark over it, as some of them may be true, some of them do not rely on real cases, what kind of display, what kind of technology is it. Sometimes the IPS displays can have higher power consumption than others, in many cases however, not. They can be more expensive, but not necessarily. The new IPS panels can cost like TN panels, but IPS panels definitely have a longer response time. Again, it is not a rule, you can make IPS panels that are very fast, faster than TN panels, but if you want the fastest possible display, probably the TN panel will be the fastest. That is why the TN technology is still popular on the gaming market. Of course, you can find a lot of discussions on the internet, which technology is better, but it really depends on what you want to achieve.
Now, let us look at the backlight types. As we see here, on the picture above, we have four distinct types of backlight possible. The most common, 95 or 99 per cent of the TFT LCD displays on the market are the transmissive LCD display type, where we need the backlight from the back. If you remember from our Monochrome LCD Displays lecture, for transmissive LCD displays you need the backlight to be always on. If you switch the backlight off, you will not see anything. The same as for monochrome LCD displays, but less popular for TFT displays, we have the transflective LCD display type. They are not popular because usually for transflective TFT displays, the colors lack in brightness, and the displays are not very practical to use. You can see the screen, but the application is limited. Some transflective LCD displays are used by military, in applications where power consumption is paramount; where you can switch the backlight off and you agree to have lower image quality but still see the image. Power consumption and saving energy is most important in some kind of applications and you can use transflective LCD displays there. The reflective type of LCD displays are almost never used in TFT. There is one technology called Low Power Reflective Displays (LPRD) that is used in TFT but it is not popular. Lastly, we have a variation of reflective displays with frontlight, where we add frontlight to the reflective display and have the image even without external light.
Just a few words about Low Power Reflective Displays (LPRD). This kind of display uses environmental light, ambient light to reflect, and produce some colors. The colors are not perfect, not perfectly clear, but this technology is becoming increasingly popular because it allows to have color displays in battery powered applications. For example, a smartwatch would be a case for that technology, or an electrical bike or scooter, where we can not only have a standard monochrome LCD display but also a TFT LCD color display without the backlight; we can see the image even in
strong sunlight and not need backlight at all. So, this kind of TFL LCD display technology is getting more and more popular when we have outdoor LCD displays and need a low power consumption.
On the picture above, we have some examples of how transmissive and reflective LCD displays work in the sunlight. If we have a simple image, like a black and white pattern, then on a transmissive LCD display, even with 1000 candela brightness, the image probably will be lower quality than for a reflective LCD display; if we have sunlight, we have very strong light reflections on the surface of the screen. We have talked about contrast in more detail in the lecture Sunlight Readable Displays. So, reflective LCD displays are a better solution for outdoor applications than transmissive LCD displays, where you need a really strong backlight, 1000 candela or more, to be really seen outdoors.
To show you how the backlight of LCD displays is built, we took the picture above. You can see the edge backlight there, where we have LEDs here on the small PCB on the edge, and we have a diffuser that distributes the light to the whole surface of LCD screen.
In addition to the backlight, we have something that is called a frontlight. It is similar to backlight, it also uses the LEDs to put the light into it, but the frontlight needs to be transparent as we have the display behind. On the example on the picture above we can see an e-paper display. The e-paper display is also a TFT display variation, but it is not LCD (liquid crystal), it is a different technology, but the back of the display is the same and it is reflective. The example you see is the Kindle 4 eBook reader. It uses an e-paper display and a frontlight a