TN (Twisted Nematic): Without an ODC (overdriving circuit), this type of panel offers the fastest pixel response time. This does however come at the expensive of viewing angles and color fidelity. Out of all TFT-LCD panels, the TN type has the lowest contrast. It is also a 6-bit color depth panel, meaning dithering or frame rate control (FRC) must be employed to reach close to a full 8-bit depth. Pixels in their active state on a TN are black, while in their inactive, white.
(P-)MVA ({Premium} Multidomain Vertical Alignment): The liquid crystal (LC) cells on MVA panels are in their active state white, and in inactive black and are separated into four domains. This slightly improves viewing angle over TN-type displays (MVAs provide ~45 degrees). MVA panels also provide a high contrast ratio. Grayscale inversion is minimal on these displays. Response time is the second slowest in the industry without ODCs.
PVA (Patterned-ITO Vertical Alignment): Developed by Samsung, PVA is very similar to MVA. Viewing angles are very similar and inversion is minimal at wide viewing angles. As far as we know, Samsung rates their PVA panels as 6-bit and the S-PVA ones as 8-bit color depth panels. These panels deliver the slowest response time.
S-PVA (Super Patterned-ITO Vertical Alignment): These types of panels deliver a full 8-bit color depth and have a structure split into eight domains. At wide viewing angles, they have less color shift and a lower black level than MVAs. According to Samsung, they have a higher contrast ratio and better response time than MVAs as well.
S-MVA (Super Multidomain Vertical Alignment): Likely similar to P-MVA from AU Optronics, Chi Mei Optoelectronics has developed the S-MVA type of panel. These also include multidomain, vertically-aligned liquid crystals so that the cells stay in the same shape at different positions, increasing brightness at wide viewing angles. According to CMO, S-MVA improves viewing angles from conventional MVA types to 80 degrees in all angles. Like other types of panels, response time has gradually improved on these as well.
IPS (In-Plane Switching): The IPS panel was pioneered by Hitachi to fix the problems that plague the VA and TN types. Like TN, most IPSes contain only a single domain, although DD-IPS (dual domain IPS) does exist. This technology sports the least distortion at wide viewing angles. Two transistors per each pixel are needed, so brighter backlighting is crucial and power consumption is higher than competing technologies, but response time benefits greatly from this. Color depth varies. One disadvantage is that a purple-black is now introduced in black colors at different viewing angles.
S-IPS (Super In-Plane Switching): LG Philips LCD improved on IPS with their S-IPS technology, which uses multiple domains of cells in its structure. These offer a lower black level, higher contrast ratio, lower response time, and a wider viewing angle than traditional IPS technology. Color depth on S-IPS panels is 8-bit. The purple-black still applies to wide viewing angles, but orange and red hues are greatly reduced versus other technologies at wider viewing angles.
AS-IPS (Advanced/Enhanced Super In-Plane Switching): These type of panels are LG Philips LCD's third generation of IPS technology. This is mainly just a wieldy moniker for improvements in the front-end driving electronics, including ODC to reduce response time, and a dynamic contrast ratio technology, raising contrast up to 1600:1. The diagonal viewing angle is also increased to 178 degrees, from 170 on S-IPS panels. AS-IPS panels very often include much brighter backlights than S-IPS types.
