Kent Displays, Inc.

Manning Ventures, Inc.

Duane Marhefka

Xiao-Yang Huang

Clinton Braganza

Sankar Barua

Todd C Ernst

Asad Aziz Khan

Erica Montbach

Nithya Venkataraman

Anthony Daniels

Mark Lightfoot

Nathan Hirt

Don Davis

Nithya Venkatataman

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. In another aspect the electronic erase circuitry includes at least one actuator that independently applies an erase voltage waveform to each of the conductive sections, and that applies erase voltage waveforms to at least two of the conductive sections in combination.

Writing device including cholesteric liquid crystal and having sectional erase

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

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. At least one SELECT ERASE actuator is included in the electronic circuitry and enables the user to adjust the select erase voltage waveform so as to adjust select erasing of the image. Also featured is a method of making select erase adjustments on the eWriter.

Selectively erasable eWriter with user adjustment

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 (VPH) of the cholesteric liquid crystal, and ii) a slow discharge portion that lasts for a time tthat is at least 10 ms.

Liquid crystal writing device with slow discharge erase

A drawing tablet device, utilizing a data capture device in connection with a pressure sensitive display, provides electronic information corresponding to images drawn on the pressure sensitive display to an external device. The drawing tablet includes a communication interface to couple the drawing tablet to the external device to transmit electronic information corresponding to images in real-time or as stored files.

Writing tablet information recording device

The invention features electronic skin including an active layer formed of bistable cholesteric liquid crystal material and articles comprising the skin, the electronic skin having uniform gray scale reflectivity. Also featured is method for producing suitable reduction pulses that will provide a display (e.g., the electronic skin) with uniform gray scale reflectivity. Reduction pulses of narrow width are used to create uniform levels of gray in the electronic skin to overcome display imperfections that cause discontinuity in the gray scale reflectivity.

Electronic skin having uniform gray scale reflectivity

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.

Video rate ChLCD driving with active matrix backplanes

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.

Power management method and device for low-power displays

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.

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Winona, OH, United States of America

Duane Marhefka