Gm Global Technolgoy Operations, Inc.

Thomas H VanSteenkiste

Nuno A Vaz

George W Smith

Erwin A Alson

An electrical contact for use with an optically responsive, polymer dispersed liquid crystal film is provided. The preferred electrical contact means consists of a pair of U-shaped, electrically conductive spring connectors. Each of these spring connectors is rigidly biased against corresponding transparent electrodes provided on each of the surrounding transparent substrates, so as to provide a compressive clamping force against the electrode. This ensures an intimate and complete electrical connection between each spring connector and each transparent electrode. The spring connector may be formed from any electrically conductive material which is sufficiently strong yet yielding and which is sufficiently anodic with respect to the electrode material, a preferred material being a suitable beryllium copper alloy when the electrodes are formed from a material such as indium-tin oxide. The preferred spring connector also provides redundant electrical contact between each electrode and itself, therefore, enabling its use in large area devices, such as window panels, wherein it is imperative that failure at a single point of electrical contact does not result in failure of the electrical connection.

Electrical contacts for polymer dispersed liquid crystal films

In an optical device containing material which is dielectric wherein the device is switchable between an inactive relatively opaque state and an activated relatively transparent state in response to the application of a driving electric field of sufficiently low frequency, a problem may arise in that the switching time between the inactive-opaque state and the activated-transparent state is increased and/or the light transmissivity in the activated-transparent state is decreased when the device is at a relatively low temperature. This problem is alleviated by applying a heating electric field of sufficiently high frequency as to heat the dielectric material while not switching the device to the activated-transparent state thereby raising the temperature of the device to decrease the switching time between the inactive-opaque state and the activated-transparent state and/or to increase the light transmissivity in the activated-transparent state. The dielectric material may be a polymer film containing dispersed liquid crystal droplets.

Optical device with dielectric heating

A method for treating rare earth permanent magnetic material is disclosed. The treatment includes soaking ribbon rare earth permanent magnetic material consisting essentially of grains of the tetragonal crystal phase RE.sub.2 TM.sub.14 B where RE is neodymium and/or praseodymium or mixtures thereof with other rare earth elements and TM is iron or mixtures of iron and cobalt, cobalt in a soaking solution of either distilled water or phosphoric acid and manganese phosphate solution, draining off the soaking solution, rinsing with distilled water while agitating to separate and remove fine powdered magnetic material, and washing and drying the remaining powder or ribbons. The treated material is taken to substantial dryness before the material is incorporated into a permanent magnet.

Method for enhancing magnetic properties of rare earth permanent magnets

In an automotive vehicle having a visual glass pane subject to collecting vision obscuring moisture in the form of ice, frost, mist, fog, etc., apparatus is provided for removing the collected moisture. Specifically, the apparatus comprises a transparent layer of dielectric material underlying the glass pane in heat conducting relationship thereto, and means for producing dielectric heating of the dielectric material to thereby heat the glass and remove the collected moisture. Preferably, the layer of dielectric material is a polymer film and the means for producing dielectric heating includes a pair of transparent electrodes extending over the layer of dielectric material. For ease of fabrication, the pair of electrodes may be interdigitated on the same side of the layer of dielectric material.

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Washington, MI, United States of America

Thomas H VanSteenkiste