The basic structure of LCD display screen

The basic structure and display principles of liquid crystal display devices.

First, the basic structure of liquid crystal display devices.

1.Polarizing plate 2. Glass substrate; 3. Common electrode 4. Orientation layer 5. Liquid crystal, 7 spacers, and 8 protective layers9.ITO pixel electrode 10. Gate insulation layer 11. Storage capacitor bottom electrode 12. TFT leakage electrode 13Semiconductor active layer 15. TFT source electrode and lead 16. Anisotropic conductive adhesive (ACF) 17.COF18. Drive IC19. Printed circuit board (PCB) 20.TCON1. Black Matrix (BM22. Color film (CF).

Two LCD display principles.

According to the driving principle, drivers can be classified into active and passive drivers. TFT-LCD active drive.The basic principle of liquid crystal display active drives is:

The liquid crystal is placed between two conductive glasses, driven by the electric field.between the two electrodes, causing the liquid crystal molecules to distort the nematic electric field.

Effect to control the transmission or masking function of the light source, to produce brightness and shade between power off and on, and to display the image. If a color filter is added, the color image can be displayed.TFT-LCD sets a switch element at each point to selectively drive each pixel in the matrix, which can realize the high resolution and quality of the display picture. Each pixel of the TFT-LCD is controlled by the TFT integrated into itself, and they are active pixels.

Basic structure and equivalent circuit of a TFT pixel.

First, the basic structure of pixels.

1.RGB is subpixel, and the three primary colors are combined to form various colors. The number of colors that can be displayed is determined by the number of bits in the RGB digital signal. N = 2ⁿ(R) X2ⁿ(G) X2ⁿ (B) = 2³ⁿ(n: The number of bits in the digital data (bit) The number of colors that can be displayed.

2.Three sub-pixels (corresponding to RGB primary colors) make up a pixel.

3.One sub-pixel is one point. Take Panel with a resolution of 1024*768 as an example.A total of 1024*768*3 (RGB points) to form.Second, the equivalent circuit of a pixel.TFT liquid crystal display, a grid of small lines on the conductive glass, electrodes arranged by thin film transistor matrix switch, at the intersection of each line is equipped with a control gate, each display point control gate with drive signal action. The volume tube matrix on the electrode opens or closes the voltage of the liquid crystal molecule according to the display signal, so that the liquid crystal molecular axis turns into "bright" or "dark" contrast, with the rate of transistor on and off as the decision step.

CLC: parallel plate capacitance.

The liquid crystal sandwiched between the upper and lower glass substrates can be equivalent to the moment when the capacitor CIC The CLC cannot hold the voltage until the next update of the picture data.

Storage capacitor.To keep the voltage on the capacitor until the next screen update.

CommonElectrode. Common electrode.