transflective color tft display pricelist

Transflective TFT modules have both transmissive and reflective modes, meaning they both transmit and reflect light. This application note will show the abilities of a transflective TFT display.

Transflective TFT modules have both transmissive and reflective modes, meaning they both transmit and reflect light. Transflective displays are unique in that they can be visible with or without a backlight. This aspect of the transflective display is beneficial for reducing power consumption of the backlight by using the reflected light to create the readable image. Because transflective displays can use reflected light to display its image there is no need to overpower the backlight to compensate for bright ambient light. This makes transflective displays a perfect solution for indoor and outdoor applications, especially in direct sunlight.

Backlights are often the largest power drain on a display. Using the ambient light to illuminate the display makes transflective displays very energy efficient and are an ideal solution for battery powered devices. For example, a cellphone will increase the brightness of its display when brought into bright ambient lighting. This results in the battery of the device to drain very quickly. Conversely, transflective displays can use this bright ambient lighting to illuminate the display which reduces the power demand of the backlight thus conserving battery life.

Transflective displays can also utilize the transmissive mode to increase the backlight in darker environments. The display can use a combination of transmissive and reflective modes to maximize power efficiency depending on the environment and ambient light available. An outdoor display could adjust the backlight power depending on how much light is available over the course of the day.

Below is an example of a transflective TFT display at different ambient lighting levels and the corresponding backlight power levels. The display in this example is a 2.0” transflective TFT (display: E20RB-FW345-N) with a white LED backlight at 345 nits. For more information on this display refer to the data sheet. Some important features of this display are below.

The first image is the transflective TFT in the transmissive mode. The transmissive mode of the transflective TFT is using the backlight at 100% brightness. The transmissive TFT is the standard TFT mode and is great for indoor applications.

Transflective TFT’s can be used all lighting environments, using both display modes, in complete darkness to full sunlight. Below is the transflective TFT in the reflective mode in bright ambient lighting. The transflective TFT below compares the reflective aspect of the display with and without the use of the backlight LED’s. The difference between fully reflective mode at 0% backlight power and 100% backlight power is minimal in direct sunlight, using the backlight in direct sunlight has little effect for the transmissive mode of a TFT.

The transflective TFT reflects the bright ambient lighting to illuminate the display. Power is conserved when opting not to use the backlight LEDs which make transflective displays energy efficient and ideal for outdoor applications. It is important to note that displays in very bright environments will appear to have reduced color. In dark environments the image will appear to be more vibrant and colorful. The perceived color variation is due to the contrast in the lighting environment. A transmissive TFT would typically have limited visibility in direct sunlight while the transflective TFT can be visible in any environment. The ambient lighting levels can compensate for the lower power consumption of the backlight without sacrificing image visibility.

A combination of the reflective and transmission modes can be used to optimize the transflective display in any ambient lighting environment. This is especially beneficial for saving power in bright environments where the backlight LEDs can be turned off. This is a small 2.0” TFT at 345 nits that would require 80mA at 3.3V to maintain a constant brightness in the transmissive mode. This power cost becomes much greater for larger TFT’s. There is little difference in the TFT appearance at 100% and 0% backlight power in full sunlight when utilizing the full reflective mode of the transflective TFT. Transflective TFT’s are a great solution for efficient power use in applications where bright ambient lighting is available.

NMLCD-05TSFis a transflective type TFT-LCD module which is sunlight readable. This module is composed of LCD panel, driver IC, and LED backlight. The resolution is 480×480.

Explore the extensive selection of wholesale transflective display LCD displays, TFT, and HMI that can be used across a range of industries, including domestic, medical, industrial, automotive, and many others. You can choose from a number of standard industry sizes and find the transf reflect display that are applicable to your required use. If you would like options that allow a smaller environmental footprint due to low power consumption, you can browse the Chip-on-Glass (COG) LCDs. COGs are designed without PCBs so have a slimmer profile.

Alibaba.com features a broad collection of smart and advanced transflective display equipped with bright, capacitive screens for the most affordable prices. These transflective display are made implying the latest technologies for a better, enhanced, and smart viewing experience. These products are of optimal quality and are sustainable so that they can last for a long time. Buy these transflective display from the leading wholesalers and suppliers at discounted prices and fabulous deals. The smart and capacitive transflective display offered on the site are applicable for all types of ads displaying, mobile screens, LCD monitors, and many more. You can use them both for commercial as well as residential purposes. These marvellous transflective display are provided with bright and strong backlights available in distinct colors for a wonderful screen viewing experience. These transflective display are not just used for LCD screens but also are used for TFT, LED, and other.

This module is engineered for high volume production. It uses a "TAB" (tape automated bonding) or "COF" (chip on flex) style flex tail mated with a thin display. The TAB connector must be soldered directly to corresponding pads on your PCB using a hot-bar soldering machine, or bonded with anisotropic adhesive using heat and pressure. High volume contract manufacturers will be familiar with this type of construction and its assembly methods.

Hot-bar soldering machines designed for prototype, rework or repair of TAB connections are available from equipment suppliers at reasonable cost. The TAB style connection requires no separate connector, so the cost is very low, and the ultra thin profile of the display is maintained. This same LCD is also available with FFC tail designed for ZIF connectors to allow its use in prototype and lower volume applications.

Sunlight readable tft lcd display included color transflective tft lcd and high brightness tft lcd,both high brightness tft LCD (transmissive display) and transflective lcd are viewable under sunlight conditions, butwhich one would be the most suitable sunlight redable lcd display for your application? let"s see the comparison in the following article.

Compare to transmissive display, transflective TFT has a reflector layer inside tft lcd cell that is in front of the backlight. The incoming light is reflected and used to illuminate the TFT display. Transflective TFT have both "transmissive" and "reflective" modes.

Both display modes work together for enhanced performance, as a result, the performance of the display content in very bright light is perfect even without any backlight on the transmissive tft lcd. Customers using a transflective TFT LCD module can save power by reducing or turning the display"s backlight off during bright environments.

Transflective TFT become more popular since the demand of requiring good performance in bright environments and direct sunlight.so that the transflective TFT displays are perfectly readable under almost any ambient light conditions. In addition, they arevery energy efficient, making them ideal for battery powered devices and mobile applications.

In the following, we make a full comparison about the high brightness tft lcd vs transflective tft lcd display in the technical parameters, display performance, and cost evaluation. After read this article, you would get a deep comprehension about sunlight readable display tft, and how to select sunlight readable tft lcd display, to choose a most suitable transflective tft lcd or high brightness tft lcd (transmisive display) for your outdoor display.

them ideal for battery powered devices and mobile applications.Customers using a transflective screen can save power by reducing or turning off the display’s backlight during bright

ratio only about 2%, they are not a significant transflective tft lcd, it is the alternative transflective lcd solution that the reflective layer is located on the back polarizer, not in the color filter, the 2% reflective ratio is too low to say it is transflective

its cost around 18 USD,So transflective tft lcd is good, but are you ready to pay more cost about your sunlight readable tft lcd display, I hope you had a answer after read this article.

When transflective LCD technology used in regular TFT LCD with a reflective function. via the imposed reflective function, the modified tft LCD can reflect the ambient light passing the LCD cell and utilize the reflected light beams as its illumination. The stronger the ambient light is, the brighter the LCD will be needed.Transflective LCD modules are with both transmissive and reflective properties, and the image display effect depends on the conditions of the ambient environment. for transflective tft lcd, the tft lcd display uses a backlight with a transmissive property in dark environments, and uses external light with a reflective property in bright environments. so the transflective lcd method allows for better color performance than transmissive tft lcd with same backlight brightness, then the transflective lcd provides similar color characteristics similar to the transmissive mode that indoor. The net Reflectance rate of regular Transflective LCD solution is from 0.9% to 8% varied from panels selected. For example, with 1.3% net reflectance rate and under 10,000 ambient sunlight conditions, the brightness gain is around 130 nits added to original backlight brightness.

You could also find more information about "what makes best sunlight readable lcd display" here :https://www.szmaclight.com/new/Sunlight-readable-display.html

Orient Display sunlight readable TFT displays can be categorized into high brightness TFT displays, high contrast IPS displays, transflective TFT displays, Blanview TFT displays etc.

The brightness of our standard high brightness TFT displays can be from 700 to 1000 nits. With proper adding brightness enhancement film (BEF) and double brightness enhancement film (DBEF) and adjustment of the LED chips, Orient Display high brightness TFT products can achieve 1,500 to 2,000 nits or even higher luminance. Orient Display have special thermal management design to reduce the heat release and largely extend LED life time and reduce energy consumption.

Our high contrast and wide viewing angle IPS displays can achieve contrast ratio higher than 1000:1 which can make readability under strong sunlight with lower backlight luminance. High brightness IPS displays have been widely accepted by our customers with its superb display quality and it has become one of the best sellers in all our display category.Transflective display is an old monochrome display technology but it has been utilized in our color TFT line for sunlight readable application. Orient Display has 2.4” and 3.5” to choose from.

Blanview TFT displays are the new technology developed by Ortustech in Japan. It can provide around 40% of energy consumption for TFT panels which can use smaller rechargeable or disposable batteries and generate less heat. The price is also lower than traditional transflective TFT displays. Orient Display is partnering with the technology inventor to provide 4.3” and 5.0”.

Orient Display can also provide full customized or part customized solutions for our customers to enhance the viewing experience. Orient Display can provide all the different kinds of surface treatments, such as AR (Anti-reflection); AG (Anti-glare), AF (Anti-finger print or Anti-smudge); AS (Anti-smashing); AM (Anti-microbial) etc. Orient Display can also provide both dry bonding (OCA, Optical Clear Adhesive), or wet bonding (OCR, Optical Clear Resin and OCG, Optical Clear Glue) to get rid of light reflective in air bonding products to make the products much more readable under sunlight and be more robust.

Touch panels have been a much better human machine interface which become widely popular. Orient Display has been investing heavy for capacitive touch screen sensor manufacturing capacity. Now, Orient Display factory is No.1 in the world for automotive capacitive touch screen which took around 18% market share in the world automotive market.

Based on the above three types of touch panel technology, Orient Display can also add different kinds of features like different material glove touch, water environment touch, salt water environment touch, hover touch, 3D (force) touch, haptic touch etc. Orient Display can also provide from very low cost fixed area button touch, single (one) finger touch, double finger (one finger+ one gesture) touch, 5 finger touch, 10 points touch or even 16 points touch.

Considering the different shapes of the touch surface requirements, Orient Display can produce different shapes of 2D touch panel (rectangle, round, octagon etc.), or 2.5D touch screen (round edge and flat surface) or 3D (totally curved surface) touch panel.

Considering different strength requirements, Orient Display can provide low cost chemical tampered soda-lime glass, Asahi (AGC) Dragontrail glass and Corning high end Gorilla glass. With different thickness requirement, Orient Display can provide the thinnest 0.5mm OGS touch panel, to thickness more than 10mm tempered glass to prevent vandalizing, or different kinds of plastic touch panel to provide glass piece free (fear) or flexible substrates need.

Of course, Orient Display can also offer traditional RTP (Resistive Touch Panel) of 4-wire, 5-wire, 8-wire through our partners, which Orient Display can do integration to resistive touch screen displays.

Engineers are always looking for lower cost, faster, more convenient interfaces to transmit signals and to accept data and commands. The numbers of available interfaces available in the market can be dazzling. Orient Display follows market trends to produce various kind of interfaces for our customers to choose.

Genetic Interfaces: Those are the interfaces which display or touch controller manufacturers provide, including parallel, MCU, SPI(,Serial Peripheral Interface), I2C, RGB (Red Green Blue), MIPI (Mobile Industry Processor Interface), LVDS (Low-Voltage Differential Signaling), eDP ( Embedded DisplayPort) etc. Orient Display has technologies to make the above interface exchangeable.

High Level Interfaces: Orient Display has technologies to make more advanced interfaces which are more convenient to non-display engineers, such as RS232, RS485, USB, VGA, HDMI etc. more information can be found in our serious products. TFT modules, Arduino TFT display, Raspberry Pi TFT display, Control Board.

Two separate colors (yellow and sky blue), make this graphic OLED module easy-to-read, unique display. Less than an inch diagonal, this lightweight display uses super low power, making it great for handheld devices.

An ePD retains the content of your Display without applied power. Only for changing the display-content, a short supply with power is necessary. Microtips has partnered with an experienced E-paper manufacturer. We represent a full series of E-paper technology, including true color to meet your specific needs.

Thin Film Transistor or TFT screens are active-matrix LCDs capable of controlling individual pixels on the screen. Thus, they assure better visibility than other variants. These flat-panel displays are suitable for a variety of applications owing to their wide range of beneficial features.

Round TFT LCDs are gaining popularity as they have become a perfect replacement for analog gauges, and they help make any application look versatile. Microtips Technology has introduced a new 3.4-inch round display, with a high resolution of 800 x 800 pixels.

High-definition Multimedia Interface (HDMI) is a proprietary technology used to transmit uncompressed audio and video data from an HDMI-compliant digital controller to a television, computer, video projector, or any other HDMI-compliant device. Microtips Technology has developed the 7" RFH70XB-1IW-LHS medium-sized HDMI display with an HDMI interface and a high resolution.

TFT (Thin Film Transistor) is a thin-film field-effect transistor display that is designed to visualize millions of clear, bright, and high-contrast color pixels. Over the years, this display has gained immense popularity owing to its several benefits.

The 7 inch low-cost color display is one of the most popular touch screen displays available for raspberry pi, HDMI display screen and other mini PCs. Featuring IPS screen with larger visible angle and more clear display effect, this 7 inch display with touch screen can be used in all environmental conditions because of its wide temperature liquid crystal fluid.

Microtips Technology has introduced a high brightness High-Definition Multimedia Interface (HDMI) interface IPS TFT LCD module. These modules are compatible and assure seamless interface with any version of Raspberry Pi Single Board Computers (SBCs), PCs, or devices such as HDTV, DVD player, or any device that is compatible with HDMI.

AMOLED (stands for Active Matrix Organic Light Emitting Diodes) display is one of the best screen technologies popularly used in today’s laptop screens and PC monitors and high-end smart phones.

The Thin-Film-Transistor display (TFT display) is an active matrix display where each pixel of the flat panel is illuminated individually. In recent times, TFT display is increasingly used in the electronics industry owing to its several benefits.

Microtips Technology, one of the leading 5-inch color TFT display module manufacturers, has introduced the new low-cost 5-inch color TFT display. The thin film transistor (TFT) technology is just another variant of the LCD technology.

Thin-film transistor (TFT) LCD displays assure improved image quality over traditional LCD displays. They offer more control over colors and images, and require less power than other technologies.

Microptips Technology has introduced a 3.9" bar type TFT display that has a high contrast ratio. This panoramic 3.9 inch RGB bar TFT LCD comes with a resolution of 480x128 pixels. This display is suitable for several modern electronic appliances like server and audio systems, auto/marine equipment, advertising displays, drone controls and many more.

Microtips Technology, one of the leading 4.3-inch TFT LCD module manufacturers, has introduced the new low-cost 4.3-inch TFT display. TFT or thin film transistor is primarily a variant of the LCD technology. TFTs are active matrix LCDs, which help improve contrast, color, and picture quality.

Thin-Film- Transistor displays or TFT displays are active matrix LCD displays that assure better color perception than regular Twisted Nematic LCDs. The demand for TFT displays has increased in recent years owing to several advantages they offer. These displays assure a clear view from any angle, and they can display millions of bright color pixels.

Microtips is proud to announce a new line of HDMI Displays designed to work seamlessly with development boards and computers like the Raspberry Pi. This video outlines our current options for these displays...

Microtips is excited to announce our 10.1”, high bright, TFT display with increased resolution and widened viewing angles. This 10.1”, WXGA 1280*800 TFT display is an IPS panel equipped with an HDMI signal input...

Simple monochrome displays, like 7 Segments & Icons, have been around for a very long time. These displays are still widely used by customers in wide variety of industries. But have you thought about Color TN Displays instead?

Microtips MTD0550AZOM-T is a 5.49 inch display module with a resolution of 1080(RGB) x 1920. This display is composed of an AMOLED panel, driver ICs, On-cell Touch Panel and FPC.

Regional Sales Manager, George, explains OLED Displays, their benefits, and other characteristics that make them better than standard Liquid Crystal Displays for some applications.

LCD is the abbreviation for liquid crystal display. An LCD basically consists of two glass plates with a special liquid between them. The special attribute of this liquid is that it rotates or “twists” the plane of polarized light. This effect is influenced by the creation of an electrical field. The glass plates are thus each coated with a very thin metallic film. To obtain polarized light, you apply a polarization foil, the polarizer, to the bottom glass plate. Another foil must be applied to the bottom glass plate, but this time with a plane of polarization twisted by 90°. This is referred to as the analyzer.

Liquids that twist the plane of polarized light by 90° are referred to as TN (Twisted Nematic). STN (Super Twisted Nematic) liquids twist the plane of polarized light by at least 180°. This gives the display improved contrast. However, this technology does color the display to a certain extent. The most common colors are referred to as yellow-green and blue mode. There is also a gray mode, which in practice is more blue than gray, however.

In order to counteract the undesired color effect, the FSTN technology uses an additional foil on the outer side, but this causes a loss of light and means that this technology is only effective with lit displays.

However, the different colors occur only in displays that are either not lit or that are lit with white light. If there is any color in the lighting (e.g. yellow-green LED lighting), it overrides the color of the display. A blue-mode LCD with yellow-green LED lighting will always appear yellow-green.Static or multiplex driving method

Small displays with a small viewing area are generally statically driven. Static displays have the best contrast and the largest possible angle of view. The TN technology fulfills its purpose to the full here (black and white display, reasonably priced). The bigger displays get, however, the more lines become necessary in static operation (e.g. graphics 128x64=8192 segments =8192 lines). Since there is not enough space on either the display or a driver IC for so many lines, multiplexing is used. The display is thus divided up into rows and columns, and there is a segment at each intersection (128+64=192 lines). Scanning takes place row by row (64x, in other words a multiplex rate of 1:64). Because only 1 row is ever active at any one time, however, the contrast and the angle of view suffer the higher the multiplex rate becomes. This makes it essential to use STN.Angle of view 6°°/12°°

Every LCD has a preferred angle of view at which the contrast of the display is at its optimum. Most displays are produced for the 6°° angle of view, which is also known as the bottom view (BV). This angle corresponds to that of a pocket calculator that is lying flat on a desktop.

12°° displays (top view, TV) are best built into a table-top unit. All displays can be read vertically from the front.Reflective, transflective, transmissive

However, the lighting also determines the optical impression made by the display, and the display mode; blue or yellow-green – does not always have an influence. Below you can see the EAP162-3N display with different types of lighting by way of example:Lighting

Standard LCDs have a temperature range of 0 to +50°C. High-temperature displays are designed for operation in the range from -20 to +70°C. In this case, however, additional supply voltage is generally required. Since the contrast of any LCD is dependent on the temperature, a special temperature-compensation circuit is needed in order to use the entire temperature range, and this is particularly true for high-temperature displays (-20 to +70°C). Manual adjustment is possible but rather impractical for the user.

However, the storage temperature of a display should never be exceeded under any circumstances. An excessively high temperature can destroy the display very quickly. Direct exposure to the sun, for example, can destroy an LCD: This is because an LCD becomes darker (in positive mode) as it gets hotter. As it gets darker, it absorbs more light and converts it to heat. As a result, the display becomes even hotter and darker... In this way, temperatures of over 100°C can quickly be reached.Dot-matrix, graphics and 7-segment displays

The first LCDs were 7-segment displays, and they are still found today in simple pocket calculators and digital watches. 7 segments allow all of the digits from 0 to 9 to be displayed.

Text displays require what is known as a dot matrix, an area consisting of 5x7=35 dots, in order to display all of the letters in the alphabet as well as various special characters. Graphics displays have a similar structure to text displays. In this case, however, there are no spaces between the lines and characters.Display drivers and controllers

The semiconductor industry now offers a very large range of LCD drivers. We generally distinguish between pure display drivers without intelligence of their own, controllers with a display memory and possibly a character set, and micro-controllers with integrated LC drivers.

Pure display drivers work in a similar way to a shift register. They generally have a serial input. They require an external pulse, and in multiplex operation with high frequency they require new display data continuously in order to achieve a refresh frequency that is as high as possible (MSM5219, UPD7225, HD44100, LC7942, etc.). An example of a genuine controller is theHD44780 for dot-matrix displays: Once it has received the ASCII code, the controller manages its character set, memory and multiplexing entirely on its own. The following controllers are widely used for graphics displays: HD61202/3, HD61830, SED1520, SED1330, T6963.

Many ask themselves, "What is the difference between an LCD display and a TFT display?" or "What is the difference between a TFT and an OLED display?". Here are these 3 sometimes extremely different display technologies briefly explained. LCD vs. TFT vs. OLED (comparison).

- The LCD (Liquid Crystal Display) is a passive display technology. The operation and the structure are described above. Passive means that an LCD can only darken or let out light. So it always depends on ambient light or a backlight. This can be an advantage because the power consumption of a LCD display is very, very low. Sometimes even less than the accumulated power consumption of an E-paper display, which in static operation requires absolutely no energy to maintain the content. To change the contents, however, a relatively large amount of power is required for an E-paper display.

LCDs can also be reflective, so they reflect incident light and are therefore legible even at maximum brightness (sunlight, surgical lighting). Compared to TFT and also OLED, they have an unbeatable advantage in terms of readability and power consumption :; the "formula" is: Sunlight = LCD.

- A TFT display (of Thin-Film Transistor) is usually a color display (RGB). From the construction and the technology it corresponds to the LCD. It is also passive, so it needs a backlight. This is in any case necessary except for a few, very expensive constructions. However, a TFT needs much more light than the monochrome relatives, because the additional structures on the glass as well as the additional color filters "swallow" light. So TFTs are not particularly energy-efficient, but can display in color and at the same time the resolution is much higher.

- OLED displays (by Organic-Light-Emitting-Diode) are as the name implies active displays - every pixel or sign generates light. This achieves an extremely wide viewing angle and high contrast values. The power consumption is dependent on the display content. Here OLEDs to TFTs and LCDs differ significantly, which have a nearly constant power consumption even with different display contents. Unfortunately, the efficiency of converting the electric current into light energy is still very poor. This means that the power consumption of OLEDs with normal content is sometimes higher than that of a TFT with the same size. Colored OLEDs are increasingly used in consumer devices, but for the industry, due to their availability and lifetime, currently only monochrome displays are suitable (usually in yellow color).

In the reaction time, the OLEDs beat each TFT and LCD by worlds. Trise and Tfall are about 10μs, which would correspond to a theoretical refresh rate of 50,000 Hz. Possibly an advantage in very special applications.

Finally the question "What is better, LCD, OLED or TFT?" Due to the physical differences you can not answer that blanket. Depending on the application, there are pros and cons to each individual technology. In addition to the above differences, there are many more details in the design and construction that need to be individually illuminated for each device. Write us an e-mail or call us: we have specialists with some 20- and 30-year experience. We are happy to compare different displays together with you.AACS and IPS technology

Once more the new AACS technology (All-Angle-Color-Stability) improves the color stability for different viewing angles. It"s providing same color for 90° straight view as for 20° or 160° bottom or top view. There"s no more color shift or inverting effect.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thin-Film Transistor Liquid Crystal Displays use thin-film transistors to control the voltage applied to the liquid crystal layer at a sub-pixel level. The structure of TFT LCDs consists of a TFT “sandwich” and a BLU (Backlight Unit). A typical configuration is shown in the schematic diagram below.

Firstly, between the back and front polarizers, TFT LCD cells are made with two glass substrates – one for color filters, the other for a TFT array – and a liquid crystal layer sandwiched in between.

For normally black TFT LCDs, if we follow along a piece of light setting off from its backlight source, it will bea)guided uniformly by LGP;b)reflected and enhanced by BEF and DBEF;c)polarized by the back polarizer;d)polarization changed by twisted LC under the voltage applied by TFT arrays;e)“tinted” red/green/blue by corresponding color filter of the subpixel;f)let through the front polarizer by matched polarization; andg)finally, it will reach the surface and appears in viewer’s eyes.

For normally white panels, processd)will be the opposite – known as the polarization rotation effect, light is twisted in a voltage-off stage and can pass through the front polarizer by default, thus displaying white normally. However, when the voltage applied increases, this polarization rotation effect would be gradually diminished. And the light would not be able to pass through the front polarizer anymore without changing its polarization. In this way, certain pixels will appear in different colors.

Normally black LCDs have higher contrast and wider viewing angles without grayscale inversion phenomenon compared to their normally white relatives. And whether TFT LCDs are normally black or white depends on their LC switching mode:

2Chen, HW., Lee, JH., Lin, BY.et al.Liquid crystal display and organic light-emitting diode display: present status and future perspectives.Light Sci Appl7,17168 (2018).https://doi.org/10.1038/lsa.2017.168

Schematic diagram of the (a) TN mode, (b) VA mode, (c) FFS mode, and (d) IPS mode. *LC orientations shown are under applied voltages. C/F stands for the color filter.

As previously mentioned, TN mode functions with the polarization rotation effect. Under traditional TN/VA display mode, the liquid crystal molecules are vertically arranged, with a relatively narrow visual angle. When an external force is exerted on the screen, the liquid crystal molecular structure will sink in a herringbone pattern to slowly recover – a pattern called vertical alignment. Therefore, an evident “water ripple” usually appears when the display surface is touched and impacts the user experience. In comparison, the VA mode provides higher contrast. And MVA (multi-domain vertical alignment) is an upgraded version of VA with improved viewing angles.

Logic Technologies began it"s life as a custom display design and manufacturing company back in 2008. Over the past 8 years we have developed hundreds of custom display solutions from 1.1" TFT displays for gaming button consoles, small true transflective TFTs, ruggedised 7" TFT and Touch Panel modules all the way to full-customised 15" computers, complete with IP67-rated stainless steel housing for ruggedized environments.

Competing with the sun is tough for outdoor display applications. But technologies allowing enhanced display readability are there to tackle the challenge. First, know how your display will be used outdoors. Is it fixed or movable, as in hand-held? Fixed is more difficult. Hand-held devices like phones are easier because you can move your wrist to compensate for exterior lighting conditions. Will it be monochrome or is color necessary? Monochrome is simple. Color is more complex. Being clear on those points is initially important.

When your end product demands the imagery and definition ofa full-color display in an outdoor application, two options are to use a true transflective color TFT LCD panel, or a sunlight-readable enhanced transmissive TFT LCD display. True transflective panels can be more expensive and are limited in available sizes. The transflective TFT cell is less common due to the additional manufacturing and design challenges associated with building the partial reflector on the active matrix backplane internal to the TFT cell. Additionally, they are subject to rapid technology changes and current models rapidly become obsolete.

It’s generally more cost-effective integrating a sunlight-readable display using standard transmissive color TFT. Additionally, transmissive displays typically fit a much wider range of display module integration requirements.

Transflective color TFT will have a contrast performance advantage over the sunlight readable enhanced display in most outdoor high ambient light scenarios. In addition to higher contrast for these specific scenarios, the transflective TFT cell will remain usable in a wider range of applications as it can remain readable in brighter conditions where the sunlight readable counterpart might become completely washed out.

Given the need for outdoor applications, and limited availability of transflective panels, a hybrid, sunlight-readable display was created. The effect is created by properly combining the right type of anti-reflective front polarizer, high efficiency rear polarizer, and high efficiency backlight reflector where the cell is then able to reuse some of the sun"s energy. Together with a higher brightness backlight, the overall image quality in high ambient light environments is greatly improved. To function in an outdoor environment, the backlight will need to be on.

In contrast, transflective display construction is easily achieved in amonochromegraphic display because it simply uses a transflective polarizer film on the outside of the liquid crystal stack, making this configuration much easier to produce. The ease of manufacturing combined with the versatility in both low and high ambient lighting environments is why monochrome transflective displays are the most common monochrome viewing format in use.

Both the sunlight-readable and transflective options reflect more light and are better suited for outdoor direct sunlight use. And to even further enhance the user experience in direct sunlight, it’s recommended to limit the image content to high-contrast images, such as large bold images or icons, and larger black on white text (not reverse) whenever possible. Shielding the display is another enhancement that can also extend the usability to help meet the challenge but may not work in every situation.

Finally, if there are any additional components on top of the display such as strengthened cover glass or touch-panels, using an optical bonding process rather than the traditional border adhesive with an air gap, will reduce the additional reflective surfaces improving the glare and sunlight usability of the display system.

If your product’s intended use is outdoors in high ambient lighting, there’s no need to settle for an off the shelf standard transmissive color TFT display. There are a few options to be able to optimize the LCD around your application. The optimal balance between performance and cost starts with the application. Simply ask the question, “Will the end user benefit adequately to justify the cost of these sunlight readability enhancements?”

LCD is the abbreviation for liquid crystal display. An LCD basically consists of two glass plates with a special liquid between them. The special attribute of this liquid is that it rotates or “twists” the plane of polarized light. This effect is influenced by the creation of an electrical field. The glass plates are thus each coated with a very thin metallic film. To obtain polarized light, you apply a polarization foil, the polarizer, to the bottom glass plate. Another foil must be applied to the bottom glass plate, but this time with a plane of polarization twisted by 90°. This is referred to as the analyzer.

Liquids that twist the plane of polarized light by 90° are referred to as TN (Twisted Nematic). STN (Super Twisted Nematic) liquids twist the plane of polarized light by at least 180°. This gives the display improved contrast. However, this technology does color the display to a certain extent. The most common colors are referred to as yellow-green and blue mode. There is also a gray mode, which in practice is more blue than gray, however.

In order to counteract the undesired color effect, the FSTN technology uses an additional foil on the outer side, but this causes a loss of light and means that this technology is only effective with lit displays.

However, the different colors occur only in displays that are either not lit or that are lit with white light. If there is any color in the lighting (e.g. yellow-green LED lighting), it overrides the color of the display. A blue-mode LCD with yellow-green LED lighting will always appear yellow-green.Static or multiplex driving method

Small displays with a small viewing area are generally statically driven. Static displays have the best contrast and the largest possible angle of view. The TN technology fulfills its purpose to the full here (black and white display, reasonably priced). The bigger displays get, however, the more lines become necessary in static operation (e.g. graphics 128x64=8192 segments =8192 lines). Since there is not enough space on either the display or a driver IC for so many lines, multiplexing is used. The display is thus divided up into rows and columns, and there is a segment at each intersection (128+64=192 lines). Scanning takes place row by row (64x, in other words a multiplex rate of 1:64). Because only 1 row is ever active at any one time, however, the contrast and the angle of view suffer the higher the multiplex rate becomes. This makes it essential to use STN.Angle of view 6°°/12°°

Every LCD has a preferred angle of view at which the contrast of the display is at its optimum. Most displays are produced for the 6°° angle of view, which is also known as the bottom view (BV). This angle corresponds to that of a pocket calculator that is lying flat on a desktop.

12°° displays (top view, TV) are best built into a table-top unit. All displays can be read vertically from the front.Reflective, transflective, transmissive

However, the lighting also determines the optical impression made by the display, and the display mode; blue or yellow-green – does not always have an influence. Below you can see the EAP162-3N display with different types of lighting by way of example:Lighting

Standard LCDs have a temperature range of 0 to +50°C. High-temperature displays are designed for operation in the range from -20 to +70°C. In this case, however, additional supply voltage is generally required. Since the contrast of any LCD is dependent on the temperature, a special temperature-compensation circuit is needed in order to use the entire temperature range, and this is particularly true for high-temperature displays (-20 to +70°C). Manual adjustment is possible but rather impractical for the user.

However, the storage temperature of a display should never be exceeded under any circumstances. An excessively high temperature can destroy the display very quickly. Direct exposure to the sun, for example, can destroy an LCD: This is because an LCD becomes darker (in positive mode) as it gets hotter. As it gets darker, it absorbs more light and converts it to heat. As a result, the display becomes even hotter and darker... In this way, temperatures of over 100°C can quickly be reached.Dot-matrix, graphics and 7-segment displays

The first LCDs were 7-segment displays, and they are still found today in simple pocket calculators and digital watches. 7 segments allow all of the digits from 0 to 9 to be displayed.

Text displays require what is known as a dot matrix, an area consisting of 5x7=35 dots, in order to display all of the letters in the alphabet as well as various special characters. Graphics displays have a similar structure to text displays. In this case, however, there are no spaces between the lines and characters.Display drivers and controllers

The semiconductor industry now offers a very large range of LCD drivers. We generally distinguish between pure display drivers without intelligence of their own, controllers with a display memory and possibly a character set, and micro-controllers with integrated LC drivers.

Pure display drivers work in a similar way to a shift register. They generally have a serial input. They require an external pulse, and in multiplex operation with high frequency they require new display data continuously in order to achieve a refresh frequency that is as high as possible (MSM5219, UPD7225, HD44100, LC7942, etc.). An example of a genuine controller is theHD44780 for dot-matrix displays: Once it has received the ASCII code, the controller manages its character set, memory and multiplexing entirely on its own. The following controllers are widely used for graphics displays: HD61202/3, HD61830, SED1520, SED1330, T6963.

Many ask themselves, "What is the difference between an LCD display and a TFT-display?" or "What is the difference between a TFT and an OLED display?". Here are these 3 sometimes extremely different display technologies briefly explained. LCD vs. TFT vs. OLED (comparison).

- The LCD (Liquid Crystal Display) is a passive display technology. The operation and the structure are described above. Passive means that an LCD can only darken or let out light. So it always depends on ambient light or a backlight. This can be an advantage because the power consumption of a LCD display is very, very low. Sometimes even less than the accumulated power consumption of an E-paper display, which in static operation requires absolutely no energy to maintain the content. To change the contents, however, a relatively large amount of power is required for an E-paper display.

LCDs can also be reflective, so they reflect incident light and are therefore legible even at maximum brightness (sunlight, surgical lighting). Compared to TFT and also OLED, they have an unbeatable advantage in terms of readability and power consumption :; the "formula" is: Sunlight = LCD.

- A TFT-display (of Thin-Film Transistor) is usually a color display (RGB). From the construction and the technology it corresponds to the LCD. It is also passive, so it needs a backlight. This is in any case necessary except for a few, very expensive constructions. However, a TFT needs much more light than the monochrome relatives, because the additional structures on the glass as well as the additional color filters "swallow" light. So TFTs are not particularly energy-efficient, but can display in color and at the same time the resolution is much higher.

- OLED displays (by Organic-Light-Emitting-Diode) are as the name implies active displays - every pixel or sign generates light. This achieves an extremely wide viewing angle and high contrast values. The power consumption is dependent on the display content. Here OLEDs to TFTs and LCDs differ significantly, which have a nearly constant power consumption even with different display contents. Unfortunately, the efficiency of converting the electric current into light energy is still very poor. This means that the power consumption of OLEDs with normal content is sometimes higher than that of a TFT with the same size. Colored OLEDs are increasingly used in consumer devices, but for the industry, due to their availability and lifetime, currently only monochrome displays are suitable (usually in yellow color).

In the reaction time, the OLEDs beat each TFT and LCD by worlds. Trise and Tfall are about 10μs, which would correspond to a theoretical refresh rate of 50,000 Hz. Possibly an advantage in very special applications.

Finally the question "What is better, LCD, OLED or TFT?" Due to the physical differences you can not answer that blanket. Depending on the application, there are pros and cons to each individual technology. In addition to the above differences, there are many more details in the design and construction that need to be individually illuminated for each device. Write us an e-mail or call us: we have specialists with some 20- and 30-year experience. We are happy to compare different displays together with you.AACS and IPS technology

Once more the new AACS technology (All-Angle-Color-Stability) improves the color stability for different viewing angles. It"s providing same