Theory Of LFT \LCD Display Modules

What Is The TN LFT Display Technology?

Starting off, let's take a quick look at the TN (twisted nematic) display, which is the most fundamental liquid crystal cell. As we can see, voltage can be used to either send light through the cell or block it.What is the difference between a monochrome LCD display and a LFT LCD display? A LFT display is referred to as active. Every cell, pixel, and subpixel is active if it contains one or more transistors.LFT stands for Thin Film Transistor, which refers to tiny, thin transistors that are integrated into the pixel rather than being located elsewhere, such as in a controller. For instance, the LFT display in a 55-inch TV has millions of transistors in each pixel. Since they are small and concealed, we cannot see them. If we zoom closer, however, we can see them in every pixel's corner.

The subpixels in the image above are the fundamental RGB (red, green, and blue) colors, and the black area contains the transistors and electronic circuits. All we need to know is that each subpixel has transistors and that there are pixels and pixels and subpixels.The display becomes active as a result, earning the name LFT display. The majority of LFT displays are colored, but there are also monochrome LFT displays that are active, include transistors, and are available. Typically, color filters on each subpixel contribute colors to the LFT LCD display. While RGB filters are more common, RGBW (red, green, blue, and white) LCD screens with additional subpixels without the filter (white) exist as well to increase the brightness of the display.

Going a little further, within the LFT cell, there is a component that we are familiar with from the monochrome LCD display lesson at Riverdi University.In addition to an electronic circuit, we also have a cell, liquid crystal, polarizers, an ITO (indium tin oxide) layer for the electrodes, and a cell. To maintain the pixel state when we turn the pixel on and off, the electronic circuit typically consists of one transistor and a few capacitors. The pixels in LFT modules are substantially more difficult to construct since we must additionally construct an electronic component in addition to the crystal component.

Because of this, producing LFT LCD technology is quite expensive. Knowing that the transistor is a type of switch that enables us to turn the pixel ON and OFF will come naturally to those who are knowledgeable with electronics. It can be done rapidly and is highly controlled because it is built into the pixel itself. Not only can we control the ON and OFF states of each pixel, but also all of the intermediate states. The cells' lights can be turned on and off in a number of phases. The typical LFT LCD panel uses 8-bit increments for each color, giving us 256 steps of brightness for each color and each subpixel.We can, at least theoretically, display more than 16 million different colors utilizing RGB pixels on our LFT LCD screen because we have three subpixels and a 24-bit color gamut, which translates to over 16 million permutations.

What Does LFT LCD Grayscale Inversion Mean?

Grayscale inversion is an additional problem with LFT screens, particularly TN LCD displays. This only occurs on one side of the screen and alters the colors depending on the viewing angle. To begin with, we must determine the type of technology a color LFT display uses.We won't need to worry about the grayscale inversion if it is an IPS display, such as the IPS display line, because all of the viewing angles will be the same and extremely high, such as 80, 85, or 89 degrees. However, if you choose to purchase an older or more widely used form of display technology, such as a TN (twisted nematic) display, you must consider where it will be used because one viewing angle will be off. You should exercise caution because most factories identify the screen's viewing direction and confuse it with the side of the inversion of the grayscale.

We already know that TN (twisted nematic) displays experience grayscale inversion, which causes the image color to abruptly change on one viewing side of the display. You must use caution because it is tough. If we look at the table below, we can see the viewing angles. The image above shows a portion of the LCD LFT specification of a TN (twisted nematic) display that includes grayscale inversion. The maximum viewing angle at which the user can view the image is defined as 70, 70, 60, and 70 degrees.Normally, we might choose the left and right sides to be 70 degrees, followed by up and down, and if we don't understand the grayscale inversion phenomenon, we might place our user on the bottom side, which is likewise 70 degrees. The viewing angle will then resemble a six o'clock direction, hence the name "six o'clock display. But you must use caution! It is best to view this display from the 12 o'clock position since, as we can see from the specification, it was designed to be a 12 o'clock display.

The 12 o'clock position, however, offers a 60-degree lower viewing angle. Why does that matter? It implies that there won't be any grayscale inversion on this side. Going to 40, 50, 60, and even a little bit more degrees will probably still allow us to view the image clearly. Perhaps with less contrast, but the colors won't be altered. We will experience a dramatic color change if we move downward from the bottom, in the direction of the grayscale inversion at 6 o'clock, and this is something we obviously want to avoid.