Polaroid Corporation

Other

Polaroid Corporation, Patent Dept.

Stewart Bennett

Leonard Polizzotto

John J Cael

Giorgio B Trapani

Narendra S Kadaba

A window whose light transmission can be mechanically controlled and varied smoothly from a high value of approximately 40% to a low value of approximately 1% is achieved without the requirement of rotation. Polarizing molecules are coated onto four different surfaces in particular patterns. When the coated panels are assembled in the disclosed manner light transmission can be modified with only small translational movements. Durability benefits are also achieved, as well as the potential for lowered heat transmission.

Polarized non-rotating variable light transmitting window

This invention relates to a new and improved light-polarizing sheet comprising molecularly oriented polyvinyl alcohol containing an oriented block segments of polyvinylene and said polyvinyl alcohol. In particular, the polarizing sheet comprises a polyvinylalcohol/polyvinylene block copolymer material wherein the polyvinylene blocks thereof are formed by molecular dehydration of a sheet of polyvinylalcohol; said sheet of polyvinylalcohol/polyvinylene block copolymer material comprising a uniform distribution of light-polarizing molecules of polyvinylalcohol/polyvinylene block copolymer material varying in the length, n, of the conjugated repeating vinylene unit of the polyvinylene block of the copolymer throughout the range of from 2 to 24; the concentration of each of said polyvinylene blocks, as determined by the absorption of wavelengths ranging from 200 to 700 nm remaining relatively constant, the degree of orientation of said light-polarizing molecules, as measured by the spectral dichroic ratio, R.sub.D, of said blocks, increasing throughout said range with increasing length, n, of said polyvinylene blocks; said polyvinylene block concentration and said degree of orientation of said molecules imparting to said sheet a photopic dichroic ratio, R.sub.D, of at least approximately 45.

High-efficiency K-sheet polarizer

A liquid-crystal display system includes a display having a bistable liquid-crystal material, such as a ferroelectric material, and two sets of electrodes disposed substantially perpendicularly to each other and on opposite sides of a layer of the liquid-crystal material. In each set of electrodes, drive circuitry is connected via resistors to front terminals of each of the electrodes, and via resistors to back terminals of each of the electrodes. The drive circuitry provides further that drivers having equal number of output drive ports are coupled via a network of electrical conductors to the front terminals and the back terminals of electrodes in each set of the electrodes in accordance with an arrangement wherein the front terminals are arranged in groups such that, within each group, the front terminals are connected to corresponding ports of a driver. A similar arrangement is provided for the connection of the back ports to a driver subject to the proviso that the terminals in the various groups are coupled to the driver ports by a permuted arrangement allowing each electrode in a set of electrodes to be unambiguously identified by a pair of driver ports wherein one port of the pair is in the driver connected to the front terminals of the electrodes and the other port is in the driver connected to the back terminals of the set of electrodes.

Bistable display with permuted excitation

An improved liquid crystal display includes, in sequence from the viewing surface to the medial plane of the display, a substantially transparent polymeric layer, a polarizing layer, a protective layer, a transparent electrode layer, an alignment layer, and a layer of liquid crystal material. The use of a polymeric layer with a polarizing layer intermediate the polymeric layer and the liquid crystal material results in a relatively lower cost display in which the optical anisotropy of the polymeric material does not adversely affect the operation of the liquid crystal display.

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Concord, MA, United States of America

Stewart Bennett