Structure and function of TFT LCD screen
The basic structure of TFT LCD module after disassembly is mainly include front bezel, LCD panel, driving circuit and backlight .
1>The front bezel is a metal part structure with snap, which is used to fix the open cell and backlight and protect the glass edge of the display screen.
2>The LCD panel is a box composed of two pieces of glass filled with liquid crystal, which is responsible for displaying various pictures.
3>The driving circuit is connected with the display screen, including flexible printed circuit (FPC), driving chip (IC) and printed circuit board (PCB), and connected with the substrate. Its function is to provide various display screen information to the display screen after power on.
4>The backlight is composed of light source, optical diaphragm, rubber frame, etc. it is used to provide special light source for TFT LCD. Because this light source is located on the back of the display surface, it is called a backlight.
As the LCD panel with the highest technical content, it is the core part of TFT LCD. The structure of the display screen is analyzed, from top to bottom are polarizing film color film (CF) substrate, liquid crystal, TFT substrate and polarizing film. The function of the polarizer is to control the light of the backlight source to only let the light in a specific direction pass through and filter out the light in other directions. The light processed by the polarizing film can control the brightness of the light emitted from the display screen through the torsion of liquid crystal molecules. So as to control the brightness and darkness of TFT LCD. The pixel voltage applied to the liquid crystal controls the torsion of the liquid crystal. The TFT switch array is integrated on the TFT substrate. The pixel voltage on this side can be accurately controlled by the TFT switch array. On the CF substrate, a pixel is divided into three sub pixels: red R, green G and blue B. the liquid crystal acting as a light valve adjusts the light amount of RGB three primary colors passing through the CF substrate to obtain the required color display.
The function of backlight is to provide a light source with uniform brightness distribution for TFT LCD. According to the different distribution positions of light sources, it is divided into side light type and straight down type. The sandwich structure of diffuser film, prism film and diffuser film needs to be designed above the backlight. The lowest diffuser film is called the lower diffuser film, which is used to homogenize the light emitted from below. The function of prism lens is to use the law of total reflection and refraction to concentrate the scattered light within a certain angle range, so as to improve the brightness within this angle range. The top diffuser film is called the upper diffuser film, which is used to protect the backlight from being dirty or scratched by external objects such as the panel, and to protect the panel from being scratched by the edge lens.
The structure of TFT LCD is complex, and each structure module has its important function. The above is a brief introduction to the basic modules of TFT LCD: front bezel, LCD panel, driving circuit and back light. Hope to help you understand LCD technology. For any questions and requirements on the customization, selection and highlighting of TFT LCD, please consult the technical personnel of Deruxi. We will provide you with the best LCD solution.