Kent State University

Other

Kent Displays, Inc.

Joseph W Doane

John L West

Slobodan Zumer

Liang-Chy Chien

Asad Aziz Khan

Janez Pirs

Bojan Marin

Silva Pirs

Igor Musevic

Robert Blinc

John Raymond West

Irina Shiyanovskaya

Tod L Schneider

Forrest Nicholson

Oleg Pishnyak

Nuno A Vaz

Giuseppe Chidichimo

Attilio Golemme

Seth E Green

Alexander J Seed

The present invention relates to a display film that may be transferred by lamination or otherwise onto a substrate. The display film is formed of a stack of layers that can include different types, arrangements, and functionality within the stack depending upon factors including the characteristics of the substrate (e.g., upper or lower, transparent or opaque, substrates) and addressing of the display (e.g., active or passive matrix, electrical or optical addressing). The layers of the stacked display film include one or more electrode layers and one or more liquid crystal layers and, in addition, may include various combinations of an adhesive layer, preparation layer, casting layer, light absorbing layer, insulation layers, and protective layers. The liquid crystal layer can include cholesteric or other liquid crystal material. The liquid crystal layer can be a dispersion of liquid crystal in a polymer matrix formed by a variety of techniques. The display film may interact with components mounted on or laminated to the substrate, including a solar cell, active matrix backplane and electrodes. The display film may be mounted onto flexible or drapable substrates such as fabric and can itself be drapable. A liquid crystal display includes the display film and a single substrate for supporting the display film. Thus, the invention offers substantial flexibility in fabrication and design that has not been previously possible in the display industry.

Single substrate liquid crystal display

A unique class of chiral additive materials is disclosed for use in cholesteric displays that possess a helical twist power substantially independent of temperature. The additives have a solubility and a helical twist power large enough to be used as a single chiral component with little dilution of the physical properties of the nematic liquid crystal host mixture. The chiral additives may be used in combination with non-chiral additives to provide a helical twisting power substantially independent of temperature suitable for cholesteric displays.

Chiral additives for cholesteric displays

An improvement in a light modulating chiral nematic liquid crystal adapted to form focal conic and twisted planar textures and a liquid crystal device employing such a material, the improvement wherein the liquid crystal material includes a plurality of essentially distinct regions within which the liquid crystal has different pitch lengths, whereby the liquid crystal can be made to reflect different wavelengths of light in different regions. The regions are created by including in the chiral nematic liquid crystal composition, a chiral material adapted to change its chirality upon photo-irradiation, in an amount effective to change the pitch length of the liquid crystal composition upon photo-irradiation. By exposing different regions of the material to increasing amounts of photo-irradiation, the pitch length of each region can be selectively tuned to reflect light of a different wavelength.

Pixelized liquid crystal display materials including chiral material

An oriented ferroelectric liquid crystal in the chiral smectic C phase with the smectic planes normal to bounding plates of a cell is interspersed with polymer which stabilizes and freezes the arrangement of the liquid crystal. The polymer which stabilizes the liquid crystal is formed by a method which includes introducing a mixture of a monomer and a ferroelectric liquid crystal between cell walls when the liquid crystal is in the isotropic phase, cooling the liquid crystal to a chiral nematic or smectic phase, and polymerizing the monomer. The cooling of the mixture can be done in the presence of a magnetic or electric field.

Method of making a ferroelectric liquid crystal cell including a cooling

An oriented ferroelectric liquid crystal in the chiral smectic C phase with the smectic planes normal to bounding plates of a cell is interspersed with polymer which stabilizes and freezes the arrangement of the liquid crystal.

Ferroelectric liquid crystal cell, a method of making it, and its use

A haze-free light modulating polymer dispersed liquid crystal (PDLC) material is disclosed which comprises a polymer which is birefringent and possesses anisotropic optical properties similar to those of the dispersed liquid crystal such that the PDLC material in its transparent state exhibits a refractive index that is matched for all directions of incident light providing for an optically clear, scatter-free film for all angles of view. Electrooptic light shutters are possible from this material which are transparent in the field OFF-state and opaque in the field ON-state or vice versa, depending upon the liquid crystal phase structure and configuration of the light shutter device.

Light modulating materials comprising a liquid crystal microdroplets

A haze-free light modulating polymer dispersed liquid crystal (PDLC) material is disclosed which comprises a polymer matrix which is birefringent and possesses anisotropic optical properties similar to those of the dispersed liquid crystal microdroplets such that the PDLC material in its transparent state exhibits a refractive index that is matched for all directions of incident light providing for an optically clear, scatter-free film for all angles of view. Electrooptic light shutters are possible from this material which are transparent in the field OFF-state and opaque in the field ON-state or vice versa, depending upon the microdroplet structure and configuration of the light shutter device.

Light modulating materials comprising a liquid crystal phase dispersed

A light modulating material consisting of droplets of liquid crystal in a clear or light transmitting, flexible plastic sheet or film, such as a cured epoxy. The light modulating material is prepared by dissolving liquid crystal in an uncured resin and then curing the resin so that droplets of liquid crystal spontaneously form and are uniformly dispersed throughout the sheet or film. The new material shows a reversible, high contrast optical response from an opaque scattering mode to a clear light transmission mode when either the temperature of the material is changed to transform the liquid crystal into the isotropic phase or an electric field is applied across the material. The material is optically responsive to strain, whereby under tension it acts to polarize incident light. Curing the material in the presence of an applied field also causes it to act as an electrically addressable polarizer.

Light modulating material comprising a liquid crystal dispersion in a

The invention provides a new liquid crystal display material prepared by the phase separation of a homogeneous solution of liquid crystal and thermoplastic resin to create in situ microdroplets of liquid crystal within a set transparent resin matrix. The new display material is characterized by ease of fabrication and the ability to be reworked by simple heating and cooling of the thermoplastic resin containing microdroplets of liquid crystal. It has been discovered that such a material fabricated from a thermoplastic resin and a liquid crystal having a liquid crystalline phase to isotropic phase transition temperature above the softening temperature of the resin exhibits a reversible field-independent memory.

Liquid crystal display material comprising a liquid crystal dispersion

The invention provides a method of controlling the rate of growth of liquid crystal microdroplets formed in situ by the phase separation of a homogeneous solution of liquid crystal and polymer. Temperature, relative concentration and choice of materials determine the microdroplet growth rate and resultant microdroplet size and density. Controlling growth rate allows for fabrication of liquid crystal display devices with optimized display characteristics and response times.

Growing community of inventors

Kent, OH, United States of America

Joseph W Doane