LCD display technology--TN display

TN-LCD is short for Twist Nematic Liquid Crystal Display.

The basic principle of TN LCD display is to place the liquid crystal between two conductive glass substrates and cause the liquid crystal separation under the action of two electrodes on the upper and lower glass substrates. 

The sub-twist deforms and changes the polarization state of the beam through the liquid crystal cell to realize the switch control of the backlight beam. If a color filter is added between two glasses, the color image display can be realized..

If the external electric field is not applied in the liquid crystal cell, because the twisted pitch of liquid crystal molecules in TN liquid crystal screen is much larger than the wavelength of visible light, when the polarization direction of the incident linear polarized light is consistent with the alignment direction of liquid crystal molecules on the glass surface, the polarization direction will be twisted 90 degrees from the other side after passing through the whole liquid crystal layer, which will emit light through the other side. Status. If a voltage is applied to the liquid crystal cell and reaches a certain value, the long axis of the liquid crystal molecule will begin to tilt along the electric field direction. Except for the liquid crystal molecule on the surface of the electrode, all the liquid crystal molecule between the two electrodes in the liquid crystal cell will be rearranged along the electric field direction. At this time, the 90 degree optical rotation function disappears and the optical rotation between the orthogonal polarizers is lost.