Abstract: A writing device includes a liquid crystal layer including cholesteric liquid crystal material. There are electrically conductive layers between which the liquid crystal layer is disposed. There is a front writing surface layer that is transparent and a back support layer between which the electrically conductive layers and the liquid crystal layer are disposed. The cholesteric liquid crystal material changes in texture by application of pressure to the front writing surface layer to create an image. A seal confines the cholesteric liquid crystal material between the front writing surface layer and the back support layer. The electrically conductive layers are adapted to enable a voltage waveform to be applied thereto that erases the image. In one aspect, the resilience to bending the writing device is defined by enabling the writing device to be bent to a radius of curvature of 100.

Abstract: A liquid crystal writing device is erased by a stylus. The liquid crystal writing device includes a liquid crystal layer including cholesteric liquid crystal material. A user applies pressure to a flexible substrate that changes reflectivity of the cholesteric liquid crystal material to form images on the liquid crystal writing device. The liquid crystal layer is disposed between electrically conductive layers. Writing device terminals are electrically conductive and connected to the electrically conductive layers. The stylus includes stylus electronics adapted to apply an erase voltage or erase voltage waveform to the writing device terminals.

Abstract: A liquid crystal device that is flexible and includes a cholesteric liquid crystal material erased by flexing. Totally free of electronics and electrically conductive electrodes, the liquid crystal device takes advantage of a reverse mode effect observed in cholesteric liquid crystals whereby pressure applied to the device changes a reflective texture to a transmissive texture to create an image. The image is erased and the device reinitialized by flexing to create reflective texture surroundings.

Abstract: A writing device includes a liquid crystal layer including reflective cholesteric liquid crystal material. There are electrically conductive layers between which the liquid crystal layer is disposed. At least one of the electrically conductive layers includes at least two conductive sections. There is a front substrate that is flexible and a back substrate between which the electrically conductive layers and the liquid crystal layer are disposed. Neither the front substrate nor the back substrate includes separated sections. Application of pressure to the front substrate changes a reflectivity of a portion of the cholesteric liquid crystal material to form an image. In one aspect, there is electronic erase circuitry including at least one actuator that independently applies an erase voltage waveform to each of at least two of the conductive sections.

Abstract: A cholesteric liquid crystal device has an optical response opposite to that of the Prior Art. The liquid crystal device takes advantage of a unique and unusual effect in cholesteric liquid crystals where pressure applied to the device with a pointed stylus, without applying a voltage, creates a transmissive texture as opposed to the planar texture of the Prior Art.

Abstract: A magnet erased writing device or eWriter includes cholesteric liquid crystal material, in which a written image is erased using magnetically activated electronic circuitry. By eliminating the mechanical erase button of Prior Art eWriters, the eWriter can be designed with a display footprint that can cover nearly the entire face of the eWriter. An erasing magnet can be used with the device, which can be handheld as, for example, by being part of a stylus. With the erasing magnet separated from the device and the mechanical erase button being omitted, the eWriter avoids unintentional erasures, a drawback of Prior Art eWriters.

Abstract: 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.

Abstract: 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.

Abstract: A liquid crystal eWriter device with user adjustable select erase includes a front substrate formed of a flexible, polymeric material. Electrically conductive layers are spaced apart from each other. A dispersion layer includes a dispersion of cholesteric liquid crystal material and polymer disposed between the electrically conductive layers, wherein pressure applied to the front substrate changes a reflectance of the cholesteric liquid crystal material forming an image. Electronic circuitry is adapted to fully and selectively erase the image by applying a full erase voltage waveform and a select erase voltage waveform, respectively, to the electrically conductive layers. The image is select erased by applying the select erase voltage waveform to the electrically conductive layers while applying pressure to the front substrate and tracing a portion of the image.

Abstract: A liquid crystal writing device includes a dispersion of cholesteric liquid crystal and polymer; a flexible substrate on which a user applies pressure that changes a texture of the cholesteric liquid crystal to form an image; electrically conductive layers between which the dispersion is disposed; and electronics adapted to apply an erase voltage waveform across the electrically conductive layers that forms a focal conic texture and erases the image. The erase voltage waveform includes: i) an erase portion at an erase voltage VE, the erase voltage VE being at least as high as a planar to homeotropic transition start voltage (VPH0) of the cholesteric liquid crystal, and ii) a slow discharge portion that lasts for a time td that is at least 10 ms.

Abstract: 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<Rd2 and d1>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<3 ?m.

Abstract: 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.

Abstract: 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.

Abstract: 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.