The structure of the TFT LCD is to place a liquid crystal in two parallel pieces of glass. There are many vertical and horizontal thin wires between the two pieces of glass. The rod-shaped crystal molecules are controlled to change direction by whether the electricity is turned on or not, and the light is refracted to produce a picture. Longer service life, lower energy consumption and lower cost than CRT.
The LCD display of liquid crystal is due to the application of an electric field on the display pixel, and this electric field is generated by the synthesis of the potential signals on the two electrodes before and after the display pixel. It is very easy to establish a DC electric field on the display pixel, but the DC electric field will cause The chemical reaction of the liquid crystal material and the aging of the electrodes rapidly reduce the display life of the liquid crystal. Therefore, an AC driving electric field must be established, and the DC component in the AC electric field is required to be as small as possible, and the DC component is usually required to be less than 50mV.
In practical applications, this alternating electric field is established by a pulsed voltage signal due to the use of a digital circuit drive. The strength of the AC electric field on the display pixel is expressed by the RMS value of the AC voltage. When the RMS value is greater than the threshold voltage of the liquid crystal, the pixel is in a display state; when the RMS value is less than the threshold voltage, the pixel does not produce electro-optic effect; when the RMS value is at the threshold value When the voltage is near, the liquid crystal will show a weak electro-optic effect, which will affect the contrast of the liquid crystal display.
The driving of the liquid crystal display is used to adjust the phase, peak value, frequency, etc. of the potential signal applied to the electrodes of the liquid crystal screen, and establish a driving electric field to realize the display effect of the liquid crystal display screen. There are many driving methods of liquid crystal display, and the commonly used driving methods are static driving method and dynamic driving method.
LCD liquid crystal display driving method
2022 04/08