The 2012 Charles Stark Draper Prize is awarded to George H. Heilmeier, Wolfgang Helfrich, Martin Schadt and T. Peter Brody “for the engineering development of the Liquid Crystal Display (LCD) utilized in billions of consumer and professional devices.”
The Liquid crystal display (LCDs) is used by virtually everyone in the modern world on a daily basis. It is the medium through which people get information from a variety of everyday devices – including calculators, clocks, computer monitors, smart phones, and television screens. T. Peter Brody, George H. Heilmeier, Wolfgang Helfrich, and Martin Schadt each made substantial contributions to its development.
George H. Heilmeier discovered the dynamic scattering mode (DSM), which resulted in the first operational LCD. Liquid crystals are materials that have properties of both liquids and crystals. DSM allows them to scatter light when a voltage is applied. Shortly after Heilmeier’s discovery, DSM LCDs could be widely found in watches and calculators.
Taking cues from Heilmeier’s work, Wolfgang Helfrich and Martin Schadt invented the twisted nematic (TN) field effect of liquid crystal displays. Unlike the DSM, the twisted nematic field effect electrically controls the polarization state of transmitted light of LCDs. It requires virtually no power and small electric fields. The contrast of light is very large, allowing short switching from dark to bright and vice versa. Helfrich and Schadt’s discovery of the TN allowed for the practical use of LCDs in nearly all of today’s flat panel LCD applications.
T. Peter Brody created the active matrix (AM) drive, which enabled an array of new capabilities for LCDs. Such capabilities consist of the display of high resolution motion pictures combined with fast response which are prerequisites for television. Brody’s AM LCD opened the door for further LCD advancements in television, including color filters and brightness-enhancement films.