Implementation

In this case, both linear polarizing filters P and A have their axes of transmission in the same direction. To obtain the 90 degree twisted nematic structure of the LC layer between the two glass plates without an applied electric field (OFF state), the inner surfaces of the glass plates are treated to align the bordering LC molecules at a right angle. This molecular structure is practically the same as in TN LCDs. However, the arrangement of the electrodes e1 and e2 is different. Electrodes are in the same plane and on a single glass plate, so they generate an electric field essentially parallel to this plate. The diagram is not to scale: the LC layer is only a few micrometers thick, very thin compared with the distance between the electrodes.

The LC molecules have a positive dielectric anisotropy and align themselves with their long axis parallel to an applied electrical field. In the OFF state (shown on the left), entering light L1 becomes linearly polarized by polarizer P. The twisted nematic LC layer rotates the polarization axis of the passing light by 90 degrees, so that ideally no light passes through polarizer A. In the ON state, a sufficient voltage is applied between electrodes and a corresponding electric field E is generated that realigns the LC molecules as shown on the right of the diagram. Here, light L2 can pass through polarizer A.

In practice, other schemes of implementation exist with a different structure of the LC molecules – for example without any twist in the OFF state. As both electrodes are on the same substrate, they take more space than TN matrix electrodes. This also reduces contrast and brightness.^[16]

Super-IPS was later introduced with better response times and colour reproduction.^{[17][unreliable source?]}

Advantages

• IPS panels display consistent, accurate color from all viewing angles.^[18] A state-of-the-art (2014) comparison of IPS vs. TN panels concerning color consistency under different viewing angles can be seen on the website of Japan Display Inc.^[19]
• Unlike TN LCDs, IPS panels do not lighten or show tailing when touched. This is important for touch-screen devices, such as smartphones and tablet computers.^[20]
• IPS panels offer clear and razor-sharp images without reflections, a wide viewing range, stable response time and better coloring.^{[21][16][unreliable source?][22]}

Disadvantages

• IPS panels require up to 15% more power than TN panels.^[23]
• IPS panels are more expensive to produce than TN panels.
• IPS panels have slower/longer response times than TN panels.^[24]
• IPS panels are sometimes vulnerable to a defect called backlight bleeding.

Plane to Line Switching (PLS)

Toward the end of 2010 Samsung Electronics introduced Super PLS (Plane-to-Line Switching) with the intent of providing an alternative to the popular IPS technology which is primarily manufactured by LG Display. It is an "IPS-type" panel technology, and is very similar in performance features, specs and characteristics to LG Display's offering. Samsung adopted PLS panels instead of AMOLED panels, because in the past AMOLED panels had difficulties in realizing full HD resolution on mobile devices. PLS technology was Samsung's wide-viewing angle LCD technology, similar to LG Display's IPS technology.^[25]

Samsung asserted the following benefits of Super PLS (commonly referred to as just "PLS") over IPS:^[26]

• Further improvement in viewing angle
• 10 percent increase in brightness
• Up to 15 percent decrease in production costs
• Increased image quality
• Flexible panel

Advanced Hyper-Viewing Angle (AHVA)

In 2012 AU Optronics began investment in their own IPS-type technology, dubbed AHVA. This should not be confused with their long standing AMVA technology (which is a VA-type technology). Performance and specs remained very similar to LG Display's IPS and Samsung's PLS offerings. The first 144 Hz compatible IPS-type panels were produced in late 2014 (used first in early 2015) by AUO, beating Samsung and LG Display to providing high refresh rate IPS-type panels.^[27][28]