In the vertically-aligned (VA) system, the LC molecules are aligned perpendicular to the substrates when no voltage is applied, thus producing a black image. When a voltage is applied, the molecules shift to a horizontal position, producing a white image. With no voltage, all the LC molecules, including those at the boundaries with the substrates, are completely perpendicular. In this state the polarised light passes through the cell without interruption from the LC molecules and is blocked by the front polarise. Because the blockage is complete, the quality of black produced in this way is excellent and the viewer sees this black from all viewing angles.
As well as an excellent viewing angle of 140 degrees all round, these VA panels can achieve faster response speeds because there is no twisted structure and the LC molecules are simply switched between the vertical and horizontal alignments. They're also capable of maximum contrast ratios of the order of 300:1, with no power penalty.