Panel Composition Of LCD Screen

LCD panel is the most important and costly component in LCD screens. Although the color effect of LCD panels is ultimately not determined by just the LCD panel (the IC chip of the panel is also crucial), it is a very important part.
The LCD panel is mainly composed of the following eight parts:
1. Backlight source (or backlight module):
Due to the fact that liquid crystal molecules themselves cannot emit light, in order to panel images, liquid crystal screens require specialized light sources to provide light, which is then deflected by the liquid crystal molecules to produce different colors. The backlight serves to provide light energy. Previously, the LCD screen used a cold cathode ray tube called CCFL, whose luminous principle is almost the same as that of fluorescent lamps, while the new LCD screen uses a LED backlight with a more energy-saving and long-life surface. After the light tube (or LED) emits light, it is distributed to various places through a light guide plate, and the direction of all the light is concentrated towards the liquid crystal molecules through a reflective plate on the back. Finally, the light is evenly distributed through the prism sheet and diffuser plate to avoid situations where the central brightness is too high and the surrounding brightness is too low.
2. Two polarizing films on the upper and lower layers:
The function of polarizing film is to allow light to pass through from one direction.
3. Upper and lower glass substrates:
A glass substrate is not just two pieces of glass, it has a groove structure on the inside and is attached with an alignment film, which allows liquid crystal molecules to be arranged neatly along the grooves. TFT thin film transistors and color filters will be affixed on both sides of the upper and lower glass layers.
4. ITO transparent conductive layer:
Its function is to provide a conductive path, divided into pixel electrodes (P level) and common electrodes (M level).
5. Thin film transistor (also known as TFT):
The commonly mentioned TFT-LCD actually refers to this thin film transistor, which functions like a switch. TFT can control the signal voltage on the IC control circuit and deliver it to the liquid crystal molecules, determining the angle of liquid crystal molecule deflection. Therefore, it is a very important component.
6. Liquid crystal molecular layer:
It is the most important element for changing the polarization state of light, which is determined by the combination of electric and elastic forces to determine its arrangement and polarization state.
7. Color filter:
The light deflected by liquid crystal molecules can only panel different gray levels, but cannot provide the three primary colors of red, green, and blue (RGB). Color filters are composed of RGB filters, which are mixed to adjust the colors and brightness of each color. Each pixel in the LCD panel is composed of three dots: red, green, and blue, with each color dot having a different grayscale variation.
8. Frame adhesive;
It is to ensure that the upper and lower glass substrates in the LCD panel can be firmly adhered together, and to "isolate" the entire internal system from external connections, preventing dust from entering and affecting the color effect.
The structure described above is the panel structure used in most LCD TVs and panels on the market. Some special products may use different accessories, but the overall architecture and working principle are basically not much different. The commonly referred to "LED backlight" refers to the improvement made in the first part of the backlight source, replacing the CCFL cold cathode ray tube with LED, while the other parts have almost no changes (the external power supply will have corresponding small adjustments). In addition, the size of the color gamut of the LCD screen is mainly determined by the backlight source of the LCD screen.