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Dynamic Scattering Mode
George Heilmeier proposed the dynamic scattering effect which causes a strong scattering of light when the electric field applied to a special liquid crystal Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. Th ... mixture exceeds a threshold value. A DSM cell requires the following ingredients: * a liquid crystal with negative dielectric anisotropy (aligns the LC long axis perpendicular to the electric field), * homeotropic alignment of the LC (i.e. perpendicular to the substrate planes), * doping of the LC with a substance that increases the conductivity of the LC to allow a current to flow. With no voltage applied the LC-cell with the homeotropically aligned LC is clear and transparent. With increasing voltage and current, the electric field tries to align the long molecular axis of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Heilmeier
George Harry Heilmeier (May 22, 1936 – April 21, 2014) was an American engineer, manager, and a pioneering contributor to liquid crystal displays (LCDs), for which he was inducted into the National Inventors Hall of Fame. Heilmeier's work is an IEEE Milestone. Biography Heilmeier was born in Philadelphia, Pennsylvania, graduated from Abraham Lincoln High School there, received his BS in Electrical Engineering from the University of Pennsylvania in Philadelphia, and his M.S.E., M.A., and Ph.D. degrees in solid state materials and electronics from Princeton University. In 1958 Heilmeier joined RCA Laboratories in Princeton, New Jersey, where he worked on parametric amplification, tunnel diode down-converters, millimeter wave generation, ferroelectric thin film devices, organic semiconductors and electro-optic effects in molecular and liquid crystals. In 1964 he discovered several new electro-optic effects in liquid crystals, which led to the first working liquid crystal displ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scattering (physics)
Scattering is a term used in physics to describe a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including particles and radiation) in the medium through which they pass. In conventional use, this also includes deviation of reflected radiation from the angle predicted by the law of reflection. Reflections of radiation that undergo scattering are often called ''diffuse reflections'' and unscattered reflections are called ''specular'' (mirror-like) reflections. Originally, the term was confined to light scattering (going back at least as far as Isaac Newton in the 17th century). As more "ray"-like phenomena were discovered, the idea of scattering was extended to them, so that William Herschel could refer to the scattering of "heat rays" (not then recognized as electromagnetic in nature) in 1800. John Tyndall, a pioneer in light scattering resear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Crystal
Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many types of LC phases, which can be distinguished by their optical properties (such as textures). The contrasting textures arise due to molecules within one area of material ("domain") being oriented in the same direction but different areas having different orientations. LC materials may not always be in a LC state of matter (just as water may be ice or water vapor). Liquid crystals can be divided into 3 main types: * thermotropic, *lyotropic, and * metallotropic. Thermotropic and lyotropic liquid crystals consist mostly of organic molecules, although a few minerals are also known. Thermotropic LCs exhibit a phase transition into the LC phase as temperature changes. Lyotropic LCs exhibit phase transitions as a function of b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homeotropic Alignment
In liquid crystals Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. Th ..., homeotropic alignment is one of the ways of alignment of liquid crystalline molecules. Homeotropic alignment is the state in which a rod-like liquid crystalline molecule aligns perpendicularly to the substrate. In the polydomain state, the parts also are called homeotropic domains. In contrast, the state in which the molecule aligns to a substance in parallel is called homogeneous alignment. There are various other ways of alignment in liquid crystals. Because homeotropic alignment is not anisotropic optically, a dark field is observed between crossed polarizers in polarizing optical microscopy. By conoscope observation, however, a cross image is observed in the homeotropic alignments. Homeotropic alignment oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
