Texas Instruments Corporation

William W Lloyd

Kenneth E Bean

A system and method for controlling the effective root mean square (RMS) voltage (Veff) across the segments of a liquid crystal display as a function of the frequency of the voltage signal applied thereto and selected parameters of the display package are described. Display parameters such as the thickness of the barrier dielectric layer and the electrical resistance of the liquid crystal material are chosen so that the ON and OFF states of the display are selectively controllable by lowering the frequency of the drive voltage signal applied to the OFF segments (Foff) a predetermined amount below that of the drive voltage signal applied to the ON segments (Fon), thereby decreasing the ratio of the effective RMS voltage Veff to the RMS voltage of the applied voltage signal (Vapp) for the OFF segments as compared to the ratio Veff/Vapp for the ON segments. The number of drive lines which can be effectively multiplexed is thereby increased. By proper selection of drive frequencies and other display parameters, temperature compensation without the need for additional sensors and circuitry is also achieved.

System and method for improving the multiplexing capability of a liquid

Disclosed are improved field-effect and bipolar semiconductor devices and the method of making them, wherein maximum junction control provides highly predictable device parameters. Low temperature epitaxial depositions provide tight junction thickness and resistivity control, and an orientation dependent etch forms grooves circumscribing portions of the host substrate and overlying epitaxial layers to provide dielectrically isolated single crystalline mesas utilized in forming electronic devices.

FET and bipolar device and circuit process with maximum junction control

Fet and bipolar device and circuit process with maximum junction control

The disclosure relates to the growth of single crystal material from polycrystalline material by combining the pedestal and cold crucible techniques to yield a method of producing large, high purity single crystals on a commercial scale. The method includes feeding a bar of polycrystalline material, such as silicon, into a cold cage which can be a cold silver crucible or the like having an aperture in the bottom thereof to permit insertion of the polycrystalline feed bar. An RF coil surrounds the cold cage and melts the silicon as it reaches into the cage, the RF coil providing a temperature to the silicon material which is slightly above the melting point thereof. A rod of single crystal material, the same as the feed bar, is positioned in the melt from the top surface of the cold cage and acts as a seed crystal. The single crystal rod is then pulled upwardly from the cage while polycrystalline silicon is fed into the cage through the aperture in the bottom thereof. By continuously forcing the polycrystalline rod into the cage and pulling a rod at the top of the cage, a large single crystal can be grown while maintaining only a small melt volume. The diameter of the single crystal rod being pulled will have a relation to the upper diameter of the cold cage as well as the ratio of the feed rate of the polycrystalline bar relative to the pull rate of the single crystalline bar.

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Richardson, TX, United States of America

William W Lloyd