James L. Fergason

Twisted nematic (TN) LCD technology, developed by James Fergason in the late 1960s, solved the critical problems that made earlier dynamic-scattering LCDs impractical for consumer products. TN-LCDs used less power, operated at lower voltages, and were far more reliable, enabling the digital watch and calculator displays that became ubiquitous in the 1970s.

Fergason held over 150 patents related to LCD technology, but the concept of liquid crystal displays originated with George Heilmeier and Richard Williams at RCA's Sarnoff Research Center. Fergason's key contribution was the practical twisted nematic field effect, which became the dominant LCD technology for decades.

Fergason co-founded International Liquid Crystal Company (ILIXCO) in the late 1960s to commercialize his twisted nematic LCD technology. ILIXCO displays were used in early digital watches and instruments, and the company was one of the first to manufacture TN-LCD products commercially.

In a TN-LCD, liquid crystal molecules are arranged in a helical twist between two polarizing filters, allowing light to pass through when no electric field is applied. When voltage is applied across the liquid crystal layer, the molecules untwist and block the polarized light, turning that pixel dark.