The LCD panel is mainly composed of the following eight major parts:
1, backlight (or backlight module):
Since the liquid crystal molecules themselves cannot emit light, the liquid crystal screen requires a dedicated light source to provide light, and then deflects the liquid crystal molecules to produce different colors if a picture is desired. The backlight plays the role of providing light energy. Before the LCD screen is used is a cold cathode ray tube called CCFL, its light-emitting principle and the fluorescent lamp is almost the same, while the new LCD screen uses a more energy-efficient, long-life LED backlight. After the lamp (or LED) emits light, the light is distributed through the light guide plate, and the direction of all the light is concentrated toward the liquid crystal molecules by the reflector on the back. Finally, the light is distributed evenly through the prism sheet and the diffuser board to avoid the situation where the center brightness is too high and the ambient brightness is too low.
2, the upper and lower two polarizers:
The role of polarizers is to let light pass through in one direction.
3, upper and lower two glass substrates:
The glass substrate is not only simpler than two glasses, but has a grooved structure on its inner side and an alignment film, which allows the liquid crystal molecules to align neatly along the grooves. A TFT thin film transistor and a color filter are attached to both sides of the upper and lower glass layers.
4, ITO transparent conductive layer:
Its role is to provide conductive paths, divided into pixel electrodes (P-level) and common electrodes (M-level).
5, thin film transistor (is what we often call TFT):
Frequently speaking, a TFT-LCD actually refers to this thin film transistor. Its function is similar to that of a switch. The TFT can control the signal voltage on the IC control circuit and send it to the liquid crystal molecules to determine the angle of deflection of the liquid crystal molecules. Size, so it is a very important part.
6, liquid crystal molecular layer:
It is the most important element for changing the polarization state of light, and it determines the alignment and polarization state of the light by the power and elasticity.
7, color filter:
The light deflected by the liquid crystal molecules can only show different gray levels, but it cannot provide three primary colors of red, green, and blue (RGB), and the color filter is composed of three kinds of RGB filters, and each of the colors is adjusted by mixing the three colors. brightness. Each pixel in the LCD panel consists of three points: red, green, and blue. Each color point has a different grayscale change.
8, box glue;
It is to allow the upper and lower glass substrates in the LCD panel to be firmly bonded together, and to “insert” the entire internal system from the external, to prevent dust from entering the color effect.