white lines on a tft display brands

Due to the fact that the issue is isolated to a single line (even with multiple pixels in height) it"s unlikely it"s the actual signal (e.g. cable or connector pins).

Some issue with the connection would most likely screw up several lines and/or the whole image and it won"t be isolated to exactly one line (especially with digital connections).

In a similar way, issues with the graphics card should most likely cause issues with the whole screen (like garbage/random patterns). Those shouldn"t be isolated to a single line.

Turn off the monitor, disconnect all cables, and put it flat on your table (screen up) so it"s sitting plane on the table. Let it sit there for a night, then try again.

If everything else fails, what happens if you use your finger nail and pull it over the faulty line? Don"t push too hard, just so there"s some pressure (typically shows some short colored trail that should disappear within 1-2 seconds). Can you see any additional patterns or "waves" that don"t fit to what you see in other areas of the screen?

The basic feature of the liquid crystal is the ability to twist on 45 degrees or 90 degrees, relative to the axis of the particles arranged in parallel between both electrode surfaces.

In LCD the light transit through two polarizers, which are arranged perpendicular, then through the liquid crystal layer. The layer can block the transition of the light or change polarization. Finally, the light falls on the color filters, which give it a set colorcreating the image.

The LCD TFT screens are built of thin-film transistors. The transistor is produced by chemical vapor deposition (CVD), based on the use of liquid hydrogen mixture and silicon mixture in an organic solvent, and using the rotation application method of the thin semiconductor.

In the TFT matrix, each pixel is controlled by four transistors, whereone of them is responsible for brightness, and three remain for basic color (red, blue, green). As a result, this solution allows the high resolution, better color and generally higher parameters of displayed images  – comparing to common LCD matrix.

Because of the material the TFT is built from, which isglass, TFT displays havelow mechanical toughness,so can be easily damaged. The most popular damage of TFT is:

The horizontal lines on the screen (Fig. 3) may indicate an interruption of the ITO lines, which control the transistors. In most cases the whole line of the transistors would be interrupted, therefore the defects are observed as a line.

The majority of damage occurs during the assembly process in the end user devices. Too much pressure on the fragile TFT construction can damage the structure of the liquid crystal or electric lines.

We recommend that you are always careful during the process of assembling the module. This special treatment is necessary to protect the matrix of the display against being hit or put under too much pressure.

The module can be held strictly by the housing, and the unnecessary thrust on display should be avoided. The disassembling of the display housing is not recommended, because this process is very destructive and in most cases, it will leave you with a damaged TFT .

The TFT is supplied with 3.3V (According to the datasheet the lines of the TFT-controller are compatible with 5V and the TFT is not destroyed till now, as I see the correct image as described above.)

Vertical and horizontal lines on the best desktop monitors can ruin the immersive effect from your display, which is especially frustrating if you’ve invested into your monitor, like one of the best curved gaming monitors. To find out how to fix annoying vertical lines or horizontal lines on an external monitor, you’ll first want to test the picture to find out what causes these lines on the computer monitor, whether the problem is from the PC, cable box or another input source, or if the fault is with the monitor, its LCD panel or internal hardware itself. And while on the topic of “vertical” lines, there are vertical monitors that exist to help make certain professions or hobbies more efficient, like coding and streaming.

Before attempting any other troubleshooting, such as fixing black bars on the side of your monitor, the first step toward finding solutions for this desktop monitor problem is to isolate the source of the issue.

The first option is to test out the image on your favorite computer screen without any peripherals connected. To do this, disconnect all cable connections and use the remote control or the control panel to disconnect Bluetooth and WiFi, if your external monitor is so equipped. If there are no vertical or horizontal lines on the default picture or menu screen, then the problem is likely due to your PC or input device, or to your cable connections. If the lines still appear, then the issue is likely to be with the external monitor itself.

If the monitor shows lines when not connected to any cables or input method, the problem is likely with the monitor itself. Image issues such as lines can be caused by damaged internal ribbon cables or the LCD panel itself. If this is the case, the repair process will depend on what the hardware problem is, whether you have a flat or curved computer monitor. If you see light leaking on the edges of your monitor screen, you may have blacklight bleed, which you can learn about in our resource content on what is blacklight bleed.

If the lines go away when your external monitor has no input, then you’ll want to look for a connection issue or an issue with your PC or laptop’s graphics drivers, driver settings, or picture settings. Additionally, you may want to check for any input lag issues with your monitor at this time.

Make sure all cables are connected securely. A loose connector can cause various picture issues including gray lines, pink lines or green lines.You may want to unplug your monitor from the input device and check the condition of the ports. You may be able to see if there are any bent or broken pins in the connectors of these input terminals. Double-check the cables if you have two monitors. If you need more organization in your space, consider the best dual monitor mount. Don’t use a paperclip or other metal object to try and clear out a VGA terminal.

If you find a damaged part, you can either consult a repair service or professional repair technician, or you might want to fix it yourself using an electronics repair kit. Use caution when removing ports, and always unplug a monitor before working on a repair.You may need to consult the owners manuals to see what types of repair tools will be needed.If the cable is faulty, the solution may be just to buy a replacement cable. That may be the best path if you need to immediately fix your monitor and can’t spend time researching and repairing the damaged part on your own, like if you use your monitor for work like a monitor for video editing.

Look for any video card drivers or graphics card driver that has a yellow exclamation mark or question mark. These common error notifications may mean your laptop or PC graphics drivers are out of date. Many graphics cards offer a driver updater tool. You can also consider buying a new, updated graphics card.

Alternatively, you can run a system scan to discover errors and graphics driver software issues. If there is a problem with your graphics card driver, it may show up on a system scan. Try booting up in safe mode or BIOS, if available; this will often show whether the display issue is a software problem or a hardware problem.

Warning: Try booting up in safe mode or BIOS, if available; this will often show whether the display issue is a software problem or a hardware problem

A screen resolution adjustment may also help. If the device picture settings are not compatible with the monitor’s native resolution, you may see errors such as lines on the screen. On a windows PC, setting a display resolution or refresh rate that is not supported can damage a monitor.This is more often a risk with older CRT monitors.

Warning: If the device picture settings are not compatible with the monitor’s native resolution, you may see errors such as lines on the screen. On a windows PC, setting a display resolution or refresh rate that is not supported can damage a monitor

Explanation of why pulse width modulated backlighting is used, and its side-effects, “Pulse Width Modulation on LCD monitors”, TFT Central. Retrieved June 2012.

So, I have a purpose built pcb with the teensy 4.0 footprint (little did I know the financial implications this would have...I"ve been through >�60 worth of teensy 4.0).

My PCB board size is about 100mm-80mm (all hand soldered with a hot air tool, soldering iron, heat bed not to blow my own trumpet, but I am very good at pcb assembly by hand + I find it therapeutic).

So after half a days soldering, I fire up the board and excellent, the ILI9341 is running at a clock speed of 100mhz (not scoped), lightning fast! Dropped the speed to a more reasonable 20mhz and left overnight for a board test (i always do this, as i have lipos connected etc and like to see if there are any heat issues etc after a 24h run). Found no issues the next morning, graphics test still running so powered off the device.

Powered back up after my return from work @20mhz and the graphics test worked fine. Enabled my SD circuitry (solder jumpers), reran the test and both the ILI9341 and SD were both running sweet.

No changes made, powered up on the third day, and nothing but a white screen on the ILI9341? So i say, must have blew the t4 some how. Hot air removed the t4, on goes the new one and again a few runs later and i get a white screen again? Checked all my pin assignments, voltages and they are all good.

I came to the conclusion that as I was forcing the T4 to be powered of of 3v3 as per (https://forum.pjrc.com/threads/64468...V-power-supply) this was somehow messing with the SPI communication. I canned the T4 and designed and built a T4-SAMD51 clone.

I picked up the project again today and de-soldered my SAMD51 T4 clone pcb as I need speed! The T4 would have been perfect, so tried a few code changes, got the screen running in the setup function (static text etc), but as soon as it enters the loop(), you guessed it....white screen. Its as if the t4 is too fast on spi or something, but I have changed the clock speeds down to 5mhz and yield the same results...

To confirm, I had the T4 intermittently working on both the adafruit ili9341 library and the optimised ili9341_t3. I"ve been through 3 T4s and I have 5 different ILI934 displays. (all give the same results, pull ups, no pullups, removed sd circuitry, ran the T4 at 5v I"ve tried it all!)

Vertical lines appearing on LCD screen is very common. Whether the screen belongs to a laptop computer or desktop PC, mobile phone, or even a television, the fault is usually due to the ribbon cable and its connections.

A faulty ribbon cable can cause all sorts of havoc manifesting in bright vertical lines. Sometimes they can be coloured lines such as blue, green, grey, black, and red. The lines can appear thick or thin and on just one-half of the screen. Sometimes the fault will manifest as two vertical white lines. You can even get horizontal lines as well.

If you have lines appearing on the LCD screen, then the first simple thing to check is the seating of the ribbon cable that connects the display panel to the motherboard. Most of the time, the fault is with the poor connection made by the ribbon cable.

One of the most common problems with ribbon cables is oxidation of the contacts. It can happen either on the ribbon cable contacts or on the socket contacts. Manufacturers often use a mix of gold and copper for the electrical contacts, however, if they have not used enough gold, then oxidation occurs over time. This results in a working television or laptop screen suddenly exhibiting lines.

The solution is of course very simple, one needs to clean the contacts with a high quality electrical contact cleaner. It is best to clean the socket and the ribbon cable contacts, which will solve the fault.

One of the most common faults with laptops is that the ribbon cable connecting to the LCD panel cracks. It typically fails near the hinge area due to flexing in that region, and over time, some of the tracks on the plastic cable breaks. I have seen these types of faults on many laptops. It does not matter whether it is a Lenovo, IBM, Acer, Samsung, Toshiba, or even a MacBook Pro!

It is also possible to have a dislodged cable, which typically occurs on mishandled laptops. The plastic clip that holds the ribbon cable is very small and delicate and if the laptop receives an impact, the ribbon cable can dislodge.

This type of fault can also occur on LCD televisions; however, it tends to be on new units, where the box has received an impact during transit from the factory.

In this situation, the repair can be easy, as the cable will simply require reseating. However, there is still the labour time to consider as it can take the best part of the day to gain access to the ribbon cable.

If the laptop has a socket that provides a VGA output, then the first thing to do is to hook up another good monitor to it to see if the picture is good. If the picture on another monitor is good, then you can be sure that the video chipset and the motherboard electronics are operating properly, and it is a connection issue.

I used this same method of troubleshooting to repair an LCD television recently. Modern televisions have a video out socket, and if you feed the signal from that to another monitor, you can check for the quality of the video display. If the external monitor does not show lines, then you know for sure that it is a connection issue. Hence, this method of troubleshooting works for some of the modern televisions as well.

When half of the vertical interlace is missing showing a picture that is broken up vertically, the display appears with vertical lines. This is usually due to a cracked ribbon cable.

Generally, for laptops a replacement cable is always required due to it breaking near the hinge. I had this Dell laptop and replacing the LCD ribbon cable solved the problem. I managed to buy a replacement from Dell for a modest price £6.00. The laptop was just outside the warranty period; however, they still shipped out the cable free of charge. This is the reason why people buy Dell. In my experience Dell tend to stand by their customers and products, and their prices for replacement parts are realistic and down to earth.

Replacing a laptop ribbon cable is simple, and the top-half of the laptop, and keyboard needs removing to gain access to the socket on the motherboard side. As you can see, it flexes near the hinge area and breaks where the ribbon cable wraps around the hinge.

I just acquired a Arduino learning kit, which includes a 20x4 LCD display. I was going to test it, so I grabbed an example "hello world" program from the Arduino docs, connected the display appropriately, and then "Voila! ... Oh, it didn"t work.".

The display lights up both its backlight and characters, however not in any desirable pattern. The first and third lines are full white (display is white-on-blue), while lines 2 and 4 are full blue. See picture:

I triple-checked all wiring for any shorts, adjusted the potentiometer to a good value and quadruple-checked the connections, and wasn"t able to find any errors.

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

In the LC filling process, if the quantity of LC injected is not enough, the spare space will form bubbles. And loose LC containing sealant will result in LC leakage.

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

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

The production of the circuit and color pixel is under micro scale, and the technology is similar to semiconductor technology. Hundreds of thousands micro materials will be printed during the production process, you can understand some of the materials not being printed correctly, which result in the point defect.

Unlike point defect, this larger scale defect is caused by the failure of external FPC or PCBA, or a bad connection between FPC and cell. Therefore, a bunch of pixels connected to these IC are out of control, and we see those defects.

Usually, assembly of cell and IC is under heat and should be positioned accurately. Problems with IC connection will be checked out very soon, followed by the adjustment on machine parameter.

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

To avoid this problem, we have to pay attention to the gap distance parameter in sealing process. By the way, newton’s rings has became a method to exam the glass sealing process in reverse .

The black matrix on CF glass or a additional shield bar is used to avoid this problem. So if this problem occurs, we have to check the CF deposition process.

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

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

Among the causes listed, thickness of the whole cell is the most critical one, and there are many factors related to that. Researches provide a lot of advice to adjust the thickness of the whole cell:

Note: We do not own the images used in this post. Feel free to contact us if they belong to you, and we’ll take them down as quickly as we possibly can.

When I try to print a green horizontal line segment on rows 0 or 1 using either draw line functions I get a white line instead. I tried with the colors red and blue and they seem to work. Also, when drawing a rect to cover the whole screen it does work properly. Is it possible that I received a faulty display?

I tried changing the defitinitions ins user_setup.h, but the problem still persists. The configuration that worked best using other demo codes was #define ST7735_REDTAB.

In this article, you will learn how to use TFT LCDs by Arduino boards. From basic commands to professional designs and technics are all explained here.

In electronic’s projects, creating an interface between user and system is very important. This interface could be created by displaying useful data, a menu, and ease of access. A beautiful design is also very important.

There are several components to achieve this. LEDs,  7-segments, Character and Graphic displays, and full-color TFT LCDs. The right component for your projects depends on the amount of data to be displayed, type of user interaction, and processor capacity.

TFT LCD is a variant of a liquid-crystal display (LCD) that uses thin-film-transistor (TFT) technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments.

In Arduino-based projects, the processor frequency is low. So it is not possible to display complex, high definition images and high-speed motions. Therefore, full-color TFT LCDs can only be used to display simple data and commands.

In this article, we have used libraries and advanced technics to display data, charts, menu, etc. with a professional design. This can move your project presentation to a higher level.

In electronic’s projects, creating an interface between user and system is very important. This interface could be created by displaying useful data, a menu, and ease of access. A beautiful design is also very important.

There are several components to achieve this. LEDs,  7-segments, Character and Graphic displays, and full-color TFT LCDs. The right component for your projects depends on the amount of data to be displayed, type of user interaction, and processor capacity.

TFT LCD is a variant of a liquid-crystal display (LCD) that uses thin-film-transistor (TFT) technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven LCDs with a few segments.

In Arduino-based projects, the processor frequency is low. So it is not possible to display complex, high definition images and high-speed motions. Therefore, full-color TFT LCDs can only be used to display simple data and commands.

In this article, we have used libraries and advanced technics to display data, charts, menu, etc. with a professional design. This can move your project presentation to a higher level.

Size of displays affects your project parameters. Bigger Display is not always better. if you want to display high-resolution images and signs, you should choose a big size display with higher resolution. But it decreases the speed of your processing, needs more space and also needs more current to run.

After choosing the right display, It’s time to choose the right controller. If you want to display characters, tests, numbers and static images and the speed of display is not important, the Atmega328 Arduino boards (such as Arduino UNO) are a proper choice. If the size of your code is big, The UNO board may not be enough. You can use Arduino Mega2560 instead. And if you want to show high resolution images and motions with high speed, you should use the ARM core Arduino boards such as Arduino DUE.

In electronics/computer hardware a display driver is usually a semiconductor integrated circuit (but may alternatively comprise a state machine made of discrete logic and other components) which provides an interface function between a microprocessor, microcontroller, ASIC or general-purpose peripheral interface and a particular type of display device, e.g. LCD, LED, OLED, ePaper, CRT, Vacuum fluorescent or Nixie.

The display driver will typically accept commands and data using an industry-standard general-purpose serial or parallel interface, such as TTL, CMOS, RS232, SPI, I2C, etc. and generate signals with suitable voltage, current, timing and demultiplexing to make the display show the desired text or image.

The LCDs manufacturers use different drivers in their products. Some of them are more popular and some of them are very unknown. To run your display easily, you should use Arduino LCDs libraries and add them to your code. Otherwise running the display may be very difficult. There are many free libraries you can find on the internet but the important point about the libraries is their compatibility with the LCD’s driver. The driver of your LCD must be known by your library. In this article, we use the Adafruit GFX library and MCUFRIEND KBV library and example codes. You can download them from the following links.

You must add the library and then upload the code. If it is the first time you run an Arduino board, don’t worry. Just follow these steps:Go to www.arduino.cc/en/Main/Software and download the software of your OS. Install the IDE software as instructed.

By these two functions, You can find out the resolution of the display. Just add them to the code and put the outputs in a uint16_t variable. Then read it from the Serial port by Serial.println(); . First add Serial.begin(9600); in setup().

First you should convert your image to hex code. Download the software from the following link. if you don’t want to change the settings of the software, you must invert the color of the image and make the image horizontally mirrored and rotate it 90 degrees counterclockwise. Now add it to the software and convert it. Open the exported file and copy the hex code to Arduino IDE. x and y are locations of the image. sx and sy are sizes of image. you can change the color of the image in the last input.

Upload your image and download the converted file that the UTFT libraries can process. Now copy the hex code to Arduino IDE. x and y are locations of the image. sx and sy are size of the image.

In this template, We just used a string and 8 filled circles that change their colors in order. To draw circles around a static point ,You can use sin();  and cos(); functions. you should define the PI number . To change colors, you can use color565(); function and replace your RGB code.

In this template, We converted a .jpg image to .c file and added to the code, wrote a string and used the fade code to display. Then we used scroll code to move the screen left. Download the .h file and add it to the folder of the Arduino sketch.

In this template, We used sin(); and cos(); functions to draw Arcs with our desired thickness and displayed number by text printing function. Then we converted an image to hex code and added them to the code and displayed the image by bitmap function. Then we used draw lines function to change the style of the image. Download the .h file and add it to the folder of the Arduino sketch.

In this template, We created a function which accepts numbers as input and displays them as a pie chart. We just use draw arc and filled circle functions.

In this template, We added a converted image to code and then used two black and white arcs to create the pointer of volumes.  Download the .h file and add it to the folder of the Arduino sketch.

In this template, We added a converted image and use the arc and print function to create this gauge.  Download the .h file and add it to folder of the Arduino sketch.

while (a < b) { Serial.println(a); j = 80 * (sin(PI * a / 2000)); i = 80 * (cos(PI * a / 2000)); j2 = 50 * (sin(PI * a / 2000)); i2 = 50 * (cos(PI * a / 2000)); tft.drawLine(i2 + 235, j2 + 169, i + 235, j + 169, tft.color565(0, 255, 255)); tft.fillRect(200, 153, 75, 33, 0x0000); tft.setTextSize(3); tft.setTextColor(0xffff); if ((a/20)>99)

while (b < a) { j = 80 * (sin(PI * a / 2000)); i = 80 * (cos(PI * a / 2000)); j2 = 50 * (sin(PI * a / 2000)); i2 = 50 * (cos(PI * a / 2000)); tft.drawLine(i2 + 235, j2 + 169, i + 235, j + 169, tft.color565(0, 0, 0)); tft.fillRect(200, 153, 75, 33, 0x0000); tft.setTextSize(3); tft.setTextColor(0xffff); if ((a/20)>99)

In this template, We display simple images one after each other very fast by bitmap function. So you can make your animation by this trick.  Download the .h file and add it to folder of the Arduino sketch.

In this template, We just display some images by RGBbitmap and bitmap functions. Just make a code for touchscreen and use this template.  Download the .h file and add it to folder of the Arduino sketch.

The speed of playing all the GIF files are edited and we made them faster or slower for better understanding. The speed of motions depends on the speed of your processor or type of code or size and thickness of elements in the code.

On a modern LCD TV screen, white (or any color) vertical lines appear when the individual “tab bonded” wire connections of the ribbon cable servicing a column of pixels on the LCD display begin to fail. It could also be a loose connection of the ribbon cable between the t-con and display.

Subsequently, question is, why has a line appeared on my TV? When a TV is showing vertical colored lines, a loose wire cable in the TV might be the cause. If you knock on the back of the TV, the vertical colored lines MAY disappear temporarily. This is a sign that a cable is loose or the T-Con board is faulty.

If your flat-screen TV has the dreaded vertical lines, half of the screen has turned darker, the screen is cracked, or the screen is broken, this can be repaired but may cost more than you paid for the complete TV. If your screen is cracked or broken, you can try replacing the Screen, LCD, Plasma, or LED part.

In this article, you will learn how to use TFT LCDs by Arduino boards. From basic commands to professional designs and technics are all explained here. At the end of this article, you can:Write texts and numbers with your own font.Draw shapes like circle, triangle, square, etc.Change screen parameters such as rotation.

fillScreen function change the color of screen to t color. The t should be a 16bit variable containing UTFT color code.#define BLACK 0x0000#define NAVY 0x000F#define DARKGREEN 0x03E0#define DARKCYAN 0x03EF#define MAROON 0x7800#define PURPLE 0x780F#define OLIVE 0x7BE0#define LIGHTGREY 0xC618#define DARKGREY 0x7BEF#define BLUE 0x001F#define GREEN 0x07E0#define CYAN 0x07FF#define RED 0xF800#define MAGENTA 0xF81F#define YELLOW 0xFFE0#define WHITE 0xFFFF#define ORANGE 0xFD20#define GREENYELLOW 0xAFE5#define PINK 0xF81F

Drawing Rectanglestft.fillRect(x,y,w,h,t);//fillRect(int16_t x, int16_t y, int16_t w, int16_t h, uint16_t t)tft.drawRect(x,y,w,h,t);//drawRect(int16_t x, int16_t y, int16_t w, int16_t h, uint16_t t)

Drawing Round Rectanglestft.fillRoundRect(x,y,w,h,r,t);//fillRoundRect (int16_t x, int16_t y, int16_t w, int16_t h, uint8_t R , uint16_t t)tft.drawRoundRect(x,y,w,h,r,t);//drawRoundRect(int16_t x, int16_t y, int16_t w, int16_t h, uint8_t R , uint16_t t)

Drawing Circlestft.drawCircle(x,y,r,t);//drawCircle(int16_t x, int16_t y, int16_t r, uint16_t t)tft.fillCircle(x,y,r,t);//fillCircle(int16_t x, int16_t y, int16_t r, uint16_t t)

Drawing Trianglestft.drawTriangle(x1,y1,x2,y2,x3,y3,t);//drawTriangle(int16_t x1, int16_t y1, int16_t x2, int16_t y2, int16_t x3, int16_t y3,// uint16_t t)tft.fillTriangle(x1,y1,x2,y2,x3,y3,t);//fillTriangle(int16_t x1, int16_t y1, int16_t x2, int16_t y2, int16_t x3, int16_t y3,// uint16_t t)

This code sets the cursor position to of x and ytft.setTextColor(t); //setTextColor(uint16_t t)tft.setTextColor(t,b); //setTextColor(uint16_t t, uint16_t b)

The second function just displays the string.t.setCursor(20, 160);t.setTextColor(WHITE);t.setTextColor(WHITE, BLACK);t.setTextSize(2);t.println("www.dayalsoft.com");

A thin-film-transistor liquid-crystal display (TFT LCD) is a variant of a liquid-crystal display that uses thin-film-transistor technologyactive matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven (i.e. with segments directly connected to electronics outside the LCD) LCDs with a few segments.

In February 1957, John Wallmark of RCA filed a patent for a thin film MOSFET. Paul K. Weimer, also of RCA implemented Wallmark"s ideas and developed the thin-film transistor (TFT) in 1962, a type of MOSFET distinct from the standard bulk MOSFET. It was made with thin films of cadmium selenide and cadmium sulfide. The idea of a TFT-based liquid-crystal display (LCD) was conceived by Bernard Lechner of RCA Laboratories in 1968. In 1971, Lechner, F. J. Marlowe, E. O. Nester and J. Tults demonstrated a 2-by-18 matrix display driven by a hybrid circuit using the dynamic scattering mode of LCDs.T. Peter Brody, J. A. Asars and G. D. Dixon at Westinghouse Research Laboratories developed a CdSe (cadmium selenide) TFT, which they used to demonstrate the first CdSe thin-film-transistor liquid-crystal display (TFT LCD).active-matrix liquid-crystal display (AM LCD) using CdSe TFTs in 1974, and then Brody coined the term "active matrix" in 1975.high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays.

The liquid crystal displays used in calculators and other devices with similarly simple displays have direct-driven image elements, and therefore a voltage can be easily applied across just one segment of these types of displays without interfering with the other segments. This would be impractical for a large display, because it would have a large number of (color) picture elements (pixels), and thus it would require millions of connections, both top and bottom for each one of the three colors (red, green and blue) of every pixel. To avoid this issue, the pixels are addressed in rows and columns, reducing the connection count from millions down to thousands. The column and row wires attach to transistor switches, one for each pixel. The one-way current passing characteristic of the transistor prevents the charge that is being applied to each pixel from being drained between refreshes to a display"s image. Each pixel is a small capacitor with a layer of insulating liquid crystal sandwiched between transparent conductive ITO layers.

The circuit layout process of a TFT-LCD is very similar to that of semiconductor products. However, rather than fabricating the transistors from silicon, that is formed into a crystalline silicon wafer, they are made from a thin film of amorphous silicon that is deposited on a glass panel. The silicon layer for TFT-LCDs is typically deposited using the PECVD process.

Polycrystalline silicon is sometimes used in displays requiring higher TFT performance. Examples include small high-resolution displays such as those found in projectors or viewfinders. Amorphous silicon-based TFTs are by far the most common, due to their lower production cost, whereas polycrystalline silicon TFTs are more costly and much more difficult to produce.

The twisted nematic display is one of the oldest and frequently cheapest kind of LCD display technologies available. TN displays benefit from fast pixel response times and less smearing than other LCD display technology, but suffer from poor color reproduction and limited viewing angles, especially in the vertical direction. Colors will shift, potentially to the point of completely inverting, when viewed at an angle that is not perpendicular to the display. Modern, high end consumer products have developed methods to overcome the technology"s shortcomings, such as RTC (Response Time Compensation / Overdrive) technologies. Modern TN displays can look significantly better than older TN displays from decades earlier, but overall TN has inferior viewing angles and poor color in comparison to other technology.

Most TN panels can represent colors using only six bits per RGB channel, or 18 bit in total, and are unable to display the 16.7 million color shades (24-bit truecolor) that are available using 24-bit color. Instead, these panels display interpolated 24-bit color using a dithering method that combines adjacent pixels to simulate the desired shade. They can also use a form of temporal dithering called Frame Rate Control (FRC), which cycles between different shades with each new frame to simulate an intermediate shade. Such 18 bit panels with dithering are sometimes advertised as having "16.2 million colors". These color simulation methods are noticeable to many people and highly bothersome to some.gamut (often referred to as a percentage of the NTSC 1953 color gamut) are also due to backlighting technology. It is not uncommon for older displays to range from 10% to 26% of the NTSC color gamut, whereas other kind of displays, utilizing more complicated CCFL or LED phosphor formulations or RGB LED backlights, may extend past 100% of the NTSC color gamut, a difference quite perceivable by the human eye.

The transmittance of a pixel of an LCD panel typically does not change linearly with the applied voltage,sRGB standard for computer monitors requires a specific nonlinear dependence of the amount of emitted light as a function of the RGB value.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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