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 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: 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: 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 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 display device includes a cholesteric liquid crystal writing tablet and a piezoelectric transducer. The piezoelectric transducer is subjected to a mechanical force that generates a voltage that is applied to the writing tablet that erases writing on the writing tablet. A further feature is a display device comprising a cholesteric liquid crystal display and a piezoelectric transducer. The piezoelectric transducer is subjected to a mechanical force that generates a voltage that is applied to the display that places the display in at least one of a color reflective planar state, a substantially transparent focal conic state and a gray scale state. Also featured is a method of erasing a cholesteric liquid crystal writing tablet.

Abstract: A device and method providing a pixel architecture that, in at least one embodiment, contains both an on/off memory element and a switching element to utilize low-power liquid crystal displays for video or near-video applications. Such an embodiment can be implemented, for example, using a pair of TFTs for implementing the memory element and switching element on a common substrate. Other embodiments can utilize actual memory devices for the memory elements. This device and method are particularly useful for driving cholestric display elements for video or near video rate applications.

Abstract: A writing/drawing tablet utilizing a data capture device such as a pressure sensitive display with data capture component that can capture data from the resulting image drawn on the device for storage. In general, Bistable Liquid Crystal Displays (BLCD), and in particular, Cholesteric Liquid Crystal Displays (ChLCDs), can be utilized in the tablet. The tablet can also be adapted to connect to external devices for displaying images being drawn on the tablet or that were previously stored.

Abstract: A device and method providing a pixel architecture that, in at least one embodiment, contains both an on/off memory element and a switching element to utilize low-power liquid crystal displays for video or near-video applications. Such an embodiment can be implemented, for example, using a pair of TFTs for implementing the memory element and switching element on a common substrate. Other embodiments can utilize actual memory devices for the memory elements. This device and method are particularly useful for driving cholestric display elements for video or near video rate applications.

Abstract: A device and method for supplying a display, such as a liquid crystal display, for example a bistable ChLCD, with drive voltages for extremely low power operation. The method and the device implementing the method provides an energy storage device and a voltage converter being utilized to store energy in the storage device, such that a display can be driven during an inactive, powered-down phase of the converter by using the stored energy to drive the display.

Abstract: A device and method for supplying a display, such as a liquid crystal display, for example a bistable ChLCD, with drive voltages for extremely low power operation. The method and the device implementing the method provides an energy storage device and a voltage converter being utilized to store energy in the storage device, such that a display can be driven during an inactive, powered-down phase of the converter by using the stored energy to drive the display.

Abstract: An apparatus and method of using a driver (e.g., a commercially available, off-the-shelf driver) designed for a traditional passive matrix liquid crystal display, such as a Twisted Nematic (TN) and supertwisted nematic (STN) displays, for example, to drive a bistable liquid crystal display.

Abstract: A display device includes an electronic display adapted to produce images, an electronic device that electrically communicates with the display and a zipper interconnect adapted to enable electrical connection between the display and the electronic device. The electronic display can be a reflective display such as a liquid crystal display or an emissive display such as one containing light emitting diodes. The electronic device that communicates with the display can be drive electronics adapted to electrically address the display so as to produce the images. In particular, the display is a cholesteric liquid crystal display that can be bistable and in the form of a passive matrix, active matrix or direct drive display. The zipper interconnect can include two rows of conductive teeth that are each electrically connected to one or more of: display electrodes, drive electronics, controller or associated electronics supported on one or more substrate portions.