The LC molecules are vertically aligned, when no voltage is impressed. This makes the screen appear black and keep a very high contrast since the LC molecules are aligned vertically near the intermediate layer as well. As soon as a voltage is being applied, the molecules get aligned in the same direction and light is let pass. This results in a white display. Due to the properties of liquid crystals, the response time a white screen needs to change to a black screen is better than the ones other methods have. Intermediate range (colors) need more time, however.
An applied voltage of a moderate amount makes the molecules tilt at a middle angle. In this state, the contrast depends on the observer's viewing angle.
The contrast depends on the angle of the LC molecules and of the MVA. The contrast depends on the angle of the perspective that the screen is viewed because the molecules are aligned at different angles. As one can see in picture 5, in the first case, contrast is heavily dependent on viewing direction. In case 2 and 3, the angle that the screen is viewed from is influencing contrast only to a minor degree. In the TN method, case 1 occurs near the intermediate layer, whereas in the MVA method, case 1 occurs when moderately high voltages are being impressed.
In order to accomplish the reproduction of shades of grey to a sufficient extent, Multi - Domain is mandatory in the VA method. The VA method in conjunction with the Multi - Domain method subdivides one cell into two or more domains (areas) and controls the tilt of the LC molecules.
In order to make Multi - Domain work, protrusions in the surface of the upper and lower substrate have to be created. The LC molecules are pre-tilted to another direction by these protrusions. This makes sure that the LC molecules get tilted uniformly in every area once a voltage is being impressed. The contrast gets averaged for different kinds of viewing angles to yield homogeneity throughout the screen area.