TN(Twisted Nematic)displays are available in different variants with different contrast and viewing angle. There are several technologies that can improve the contrast ratio of TN cells. Multi-Domain Vertical Alignment (MVA) and Pattern Vertical Alignment( PVA) are such techniques to increase contrast. In these technologies, contrast enhancement is achieved with polarization filters and reflection techniques.
In Multi-Domain Vertical Alignment (MVA) technology, the individual cells are divided into multiple levels, hence the name multi- domain. The crystals in the domains are aligned differently. Thus, when one domain allows light to pass through, the crystals in the neighboring domain are at an angle and block the light. The division into domains is used to control the tilting of the liquid crystals, which are aligned vertically to the substrate surfaces without applied voltage and align perpendicular to the electric field lines when an electric field is applied. The response time for alignment was relatively long compared to TN technology, and is a disadvantage of MVA technology. Modern MVA technologies compensate for this disadvantage.
One advantage of MVA technology is its wide viewing angle, which is over 160 degrees in both axes - vertical and horizontal. In addition, this technology increases the contrast ratio to over 1,000:1. A disadvantage, however, is the inertia of the MVA technology, which is less suitable for moving image displays.