Kent Displays, Inc.

Kent State University

Erica Montbach

Asad Aziz Khan

Clinton Braganza

J William Doane

Mark Lightfoot

Donald R Diehl

Mauricio Echeverri

Nithya Venkataraman

Matthew Schlemmer

Thomas R Welter

Duane Marhefka

Tod L Schneider

Todd C Ernst

Forrest Nicholson

John Krinock

Nithya Venkatarman

A liquid crystal writing device with enhanced line acuity includes the following features. Included is a front writing surface. A liquid crystal layer includes a dispersion of cholesteric liquid crystal and polymer, wherein a reflectance of the cholesteric liquid crystal changes in response to pressure applied to the front writing surface so as to form an image on the liquid crystal layer. The liquid crystal layer is disposed between electrically conductive layers. A second of the electrically conductive layers is more distal from the front writing surface than a first of the electrically conductive layers is from the front writing surface. A backing supports the pressure applied to the front writing surface. An adhesive layer is disposed between the second of the electrically conductive layers and the backing. A line acuity of the image has a value of not more than 3.0 determined according to the Line Acuity Measurement Method of this disclosure.

Ewriter with enhanced line acuity

A liquid crystal eWriter system with a resistive digitizer and having palm rejection includes the following features. An eWriter includes eWriter substrates that are spaced apart from each other, an upper one of the eWriter substrates being formed of a flexible, clear polymeric material and a lower one of the eWriter substrates being formed of a flexible polymeric material. Electrically conductive layers are spaced apart from each other and located between the eWriter substrates. A dispersion layer including a dispersion of cholesteric liquid crystal material and polymer is disposed between the electrically conductive layers. Pressure applied to the eWriter changes a reflectance of the cholesteric liquid crystal material forming an image. A resistive digitizer determines a location of the pressure applied to the eWriter. The system is designed so that the resistive digitizer detects fingernail or stylus input with substantially no lightly written stroke loss but detects substantially no palm input, under ordinary writing conditions.

Liquid crystal eWriter system with resistive digitizer and having mechanical palm rejection

An enhanced brightness cholesteric liquid crystal eWriter device for writing and drawing includes substrates and electrically conductive layers disposed on the substrates. There is a gap, d, between the electrically conductive layers. Polymer dispersed cholesteric liquid crystal material is disposed in the gap. The polymer dispersed cholesteric liquid crystal material exhibits a written reflectance, R, which occurs in response to pressure applied to one of the substrates that changes reflectance of the cholesteric liquid crystal material. The device follows the relationship Rd1&#x3c;Rd2 and d1&#x3e;d2, where Rd2 is a written reflectance of an eWriter device of gap d2 and Rd1 is written reflectance of another eWriter device of gap d1. Further, a cholesteric liquid crystal eWriter device includes a layer of cholesteric liquid crystal material in a cell gap, d, wherein d&#x3c;3 &#x3bc;m. Also included is an enhanced brightness eWriter with other features and a method of constructing an enhanced brightness, cholesteric liquid crystal eWriter.

Enhanced brightness eWriter device

A cholesteric liquid crystal (ChLC) electronic writing device incorporates a dot pattern recognition system. When writing pressure is applied to the writing device an image composed of writing or drawing is displayed by a pressure sensitive ChLC polymer dispersion stacked in a multilayer system of the device. A specialized stylus with sensor and associated electronics is used to form the image on the electronic writing device. The stylus produces electrical information indicating the path or trajectory of the writing that is displayed by the electronic writing device, which can be transferred via wireless signal to any other displaying device. This forms a replica image on the displaying device that is a replica of the image on the electronic writing device.

Electronic writing device with dot pattern recognition system

An electronic display includes electrically conductive layers. An active layer is disposed between adjacent electrically conductive layers. The active layer includes cholesteric liquid crystal material. At least one transparent front substrate is disposed adjacent one of the electrically conductive layers near a front of the display. A semitransparent back layer absorbs light that passes through the active layer, reflects grey light or light of a color and is light transmitting. Electronic circuitry applies a voltage to the conductive layers that enables at least one of erasing or writing of the active layer.

Electronic display with semitransparent back layer

A multicolored pressure sensitive liquid crystal device includes a first transparent substrate that is flexible on which pressure is applied and a second substrate spaced apart from the first substrate. Also included are electrically conductive layers, one of which is in contact with the first substrate and is transparent and another of which is in contact with the second substrate. The electrically conductive layers are separated from each other. Also included is a pressure sensitive liquid crystal layer including cholesteric liquid crystal disposed between the electrically conductive layers. The liquid crystal layer includes at least first and second color regions. The first color region reflects light of a first color and the second color region reflects light of a second color. The pressure applied to the substrate results in a change in reflectance of the liquid crystal. In another aspect, the liquid crystal layer can include at least first and second regions that differ from each other in terms of a characteristic selected from the group consisting of wavelength of reflection, reflectivity, linewidth, electrooptic response, pressure sensitivity and combinations thereof.

Multicolored pressure sensitive liquid crystal device

An electronic display includes electrically conductive layers. At least one active layer is disposed between adjacent electrically conductive layers. The active layer includes cholesteric liquid crystal material. The display includes a front transparent substrate behind which the electrically conductive layers are disposed. A back component is disposed at a back of the display below the active layer. At least one patterned layer is disposed at at least one of the following locations: on, in or near the front substrate and as an interlayer between the front substrate and the back component. The patterned layer is opaque or semitransparent. Electronic circuitry applies a voltage to the conductive layers that enables at least one of erasing or writing of the active layer. The active layer and the patterned layer cooperate to produce an image on the display.

Electronic display with patterned layer

A system including a cholesteric liquid crystal (ChLC) display device and an erasing device. The display device (e.g., a writing tablet, liquid crystal paper) is inductively coupled to the erasing device for inductively erasing an image on the display device. Also featured is a ChLC display device that can be inductively erased.

Inductive switching of cholesteric liquid crystal display device

A cholesteric liquid crystal writing board display device includes a plurality of cholesteric liquid crystal writing tablets and a front cover layer extending over the cholesteric liquid crystal writing tablets. The cholesteric liquid crystal writing tablets are tiled together by the front cover layer such that the writing board display device appears nearly seamless. Or, the writing tablets can be spaced apart from each other.

Cholesteric writing board display device

A liquid crystal composition comprising a chiral dopant compound represented by the following structure (Structure 1): 

2,2'-binaphthalene ester chiral dopants for cholesteric liquid crystal displays

A liquid crystal composition comprising a chiral dopant compound represented by the following structure (Structure 1):  Also featured are liquid crystal compositions comprising a chiral dopant compound represented by any of Structure 2-4 as described in the disclosure.

A liquid crystal composition comprising a chiral dopant compound represented by the following formula: wherein:R1, R2 are independently aryl, alkyl, alkenyl, cycloalkyl, alkoxyaryl, alkaryl or heterocyclic all either substituted or unsubstituted, or combine to form a carbocyclic or heterocyclic ring;R3 and R4 are independently hydrogen, halogen, cyano, alkoxy, NHCOR7, NHSO2R7, COOR7, OCOR7, aryl, alkyl, alkenyl, cycloalkyl, alkoxyaryl, alkaryl or heterocyclic all either substituted or unsubstituted, or combine with either R1 or R2 to form a carbocylic or heterocyclic ring;R5 and R6 are independently hydrogen, CH2, CH, alkyl or aryl either substituted or unsubstituted, COOR7, or combine with L to form a carbocyclic or heterocyclic ring;R7 is aryl, alkyl, alkenyl, cycloalkyl, alkoxyaryl or heterocyclic all either substituted or unsubstituted;L is the non-metallic elements required to form a carbocyclic or heterocyclic ring, or a single bond or a double bond;m is 1-3;n is 0-12.

Tetraoxybiphenyl ester chiral dopants for cholesteric liquid crystal displays

Electrooptical displays require conductors on both sides of the liquid crystal thin film. The two conductors face opposite sides of the display. The cost of electrically connecting to these displays can be decreased by having the conductors of the display all face the same side of the display. This invention includes a technique to allow both conductors to face the same side of the display.

Electrooptical display with electrical crossover

The invention comprises a stacked color photodisplay apparatus using a photosensitive cholesteric liquid crystalline material on which an image can be optically addressed, retained without degradation for an indefinite period of time, electrically erased and a new image addressed. This is similar to a photographic film except that the photodisplay film can be used over and over again similar to digital display but without the cost of addressing electronics. Included is a device for enhancing the brightness of the image and electrooptical devices for optically writing digital images on the photodisplay. Each cell in the stack can be selectively addressed with a different optical image such as the red, green and blue components of a color digital image.

Growing community of inventors

Kent, OH, United States of America

Erica Montbach