twistednematic

Twisted nematic (TN) is a mode of liquid crystal display technology used in many color LCD panels. It relies on nematic liquid crystal molecules that are aligned to form a 90-degree twist between two glass substrates. The cell is placed between two polarizers arranged perpendicular to each other. In the absence of an electric field, the twisted molecules rotate the plane of polarized light as it travels through the cell, so the light passes the second polarizer and the pixel appears bright. When a voltage is applied across the cell through transparent electrodes, the molecules realign with the electric field, the twist is suppressed, and the second polarizer blocks most of the light, producing a dark pixel. The driving voltage is typically alternating current to prevent chemical degradation of the liquid crystal material.

TN is valued for its simple construction, high transmittance, and fast response times, contributing to lower cost and good gray-scale performance in early LCDs. The technology is commonly used with rapid pixel switching in gaming monitors and mobile displays, though it is more prone to color and brightness shifts when viewed from off-center angles. Color displays require color filters, and uniformity can vary with temperature and aging.

Emerging technologies such as in-plane switching (IPS) and vertical alignment (VA) formed later, offering improved viewing angles and color accuracy but at higher cost. TN remains in use in budget screens and high-speed gaming panels where fast response and low input lag are prioritized. The term twisted nematic distinguishes this mode from other liquid-crystal modes, such as super-twist nematic (STN) and optically compensated variants.