Abstract: Photovoltaic devices or solar cells are provided having one or more photoactive layers where at least one of the photoactive layers comprises a sublayer made of photoactive nanoparticles that differ in size, composition or both.

Abstract: In general, the invention relates to the field of photovoltaics or solar cells. More particularly the invention relates to photovoltaic devices using metal oxide nanostructures in connection with photoactive nanoparticles including nanoparticles of different size and composition to form a photovoltaic device.

Abstract: This invention relates to photovoltaic devices made with photoactive nanostructures comprising carbon nanotubes and photosensitive nanoparticles.

Abstract: An electroluminescent device contains (1) first and second electrodes, at least one of which is transparent to radiation; (2) a hole conducting layer containing first nanoparticles wherein the hole conducting layer is in contact with said first electrode; (3) an electron conducting layer containing second nanoparticles where the electron conducting layer is in contact with the hole conducting layer and the second electrode; and optionally (4) a voltage source capable of providing positive and negative voltage, where the positive pole of the voltage source is connected to the first electrode and the negative pole is connected to the second electrode. In some embodiments, the electroluminescent device also includes an electron-hole combination layer between the hole and electron conducting layers.

Abstract: System, device, and method for receiving or sensing touch or light input to an emissive display such as to a OLED display using the same or different sensors as are used to sense and maintain a pixel luminance. Penlight and touch screen data input system and method for display. A sidelight illuminated display and touch panel input device. Method and device for reading display pixel emission and ambient luminance levels. Emissive display having sensing for luminance stabilization and user light or touch screen input. Method and device for emissive display using shielded or partially shielded sensors. Emissive pixel display device characterized in that photon sensors are disposed within pixels and operated to sense photons emitted by emitter within pixel and ambient photons emitted by sources outside pixel, sensed internally emitted photons being for luminance feedback control and sensed ambient photons being used to detect external light source or sources.

Abstract: The present invention uses an interrupted loop feedback technique to control emissive pixels of a printhead of a printer. The interrupted loop technique involves varying the input voltage to the organic light emitting diode (OLED) of the pixel until the pixel emits the desired intensity of light. The input voltage value is locked when the pixel emits the desired intensity of light. The present invention also uses a page wide array of OLED to simultaneously emit image data for printing an image on a paper.

Abstract: The present invention provides techniques to calibrate the emissive pixels used in printers and displays. The emissive pixels are arranged in a linear array or in a two dimensional array. For the transparent substrate on which the emissive pixels are formed, the light emitted by a pixel is measured by attaching one or more optical sensors, either directly or via optical fibers, to the transparent surfaces of the transparent substrate. That measurement is compared to a reference value and corrections are accordingly made to the emissive pixels. In case of a printer, the emissive pixels can be tested for their luminescent strengths in the period following the printing of a page while the next page to be printed is being positioned.

Abstract: The present invention uses an open loop feedback technique to control emissive pixels of a printhead of a printer. The open loop feedback technique involves measuring the light intensity of the emissive pixel, comparing the measured value to a preset threshold value, and adjusting the input voltage to the OLED of the pixel based on the comparison.

Abstract: The present invention discloses novel top emitter pixel circuitry for flat panel displays. Sensor material is deposited above a substrate. A pixilated opaque cathode is deposited above the sensor material. Organic light emitting diode material is deposited above the cathode. A transparent anode is deposited above the OLED material. Some of the layers have dielectric layers between them. The light emitted by the OLED material passes upwards through the transparent anode but cannot pass downwards through the opaque cathode. A deep via optically connects the OLED material layer with the sensor material layer. A transparent cathode can be used instead of the opaque cathode, thereby allowing the light generated by the OLED material layer to pass both upward through the transparent anode and downward through the transparent cathode. That would eliminate the need for a deep via to form an optical path between the OLED material layer and the sensor layer.

Abstract: The present invention provides techniques for emissive pixels of flat panel displays. Specifically, pixel feedback and a combination of voltage modulation and pulse width modulation are used to improve the quality and consistency of aging pixels. Based on feedback, an image frame is divided into sub-frames of various time periods. Also based on feedback, a voltage, or voltages of different voltage levels, is (are) applied to the selected sub-frames to generate an image frame of a particular gray level. The human eye integrates the effects of the voltage and pulse width modulation techniques that are applied to the various sub-frames of the image frame, over the duration of the image frame.

Abstract: The present invention uses an open loop feedback technique to control emissive pixels of a printhead of a printer. The open loop feedback technique involves integrating the light intensity of the emissive pixel over a predetermined period of time, averaging the integrated value, comparing the averaged value to a threshold value, and adjusting the input voltage to the OLED of the pixel based on the comparison.

Abstract: Self-calibrating emissive pixel circuit, device and method for operating pixel. Method for operating includes: establishing sensor capacitor at predetermined starting voltage, delivering current to photon emitting device to cause photons to be emitted at predetermined target photon emission level, exposing sensor having electrical properties that vary according to photon flux on sensor to the emitted photon emission during at least portion of display frame time, permitting sensor capacitor to either charge or discharge from predetermined starting state through the sensor so that portion of frame time and resistance of sensor during portion of frame time determine amount of charge on sensor capacitor, measuring voltage or charge remaining on sensor capacitor at end of portion of frame time as indication of integrated photon flux and pixel luminance, and modifying image voltage and/or current applied to pixel during any subsequent display frame time using measured voltage as feedback parameter.

Abstract: System, device, and method for operating active-matrix emissive pixel display device. Method includes storing calibration value for pixels and gray levels displayed by pixels in memory; storing transformation in memory for transforming first representations of gray level values to second representations; receiving first gray level representations of image pixel gray level values; transforming first representations to second representations for each pixel; generating image data and control signals for driving pixels during present display frame time; generating integrated photon flux signal for pixels in display indicative of integrated photon flux during portion of present display frame time; comparing plurality of integrated photon flux signals with calibration values on pixel-by-pixel basis and generating plurality of comparison results indicating difference; and identifying deviation for each pixel and directing change in stored transformation to be applied during subsequent time.

Abstract: System and method for controlling luminance of pixel in display. Method includes storing transformation between digital image gray level value and display drive signal that generates luminance from pixel corresponding to digital gray level value; identifying target gray level value for particular pixel; generating display drive signal corresponding to identified target gray level based on stored transformation and driving particular pixel with drive signal during first display frame; measuring parameter representative of actual measured luminance of particular pixel at a second time after the first time; determining difference between identified target luminance and actual measured luminance; modifying stored transformation for particular pixel based on determined difference; and storing and using modified transformation for generating display drive signal for particular pixel during frame time following first frame time.

Abstract: A stabilized feedback display system and method for maintaining uniform pixel luminances in a display device. System includes a display device having a plurality of emissive picture elements (pixels) each formed from at least one electronic circuit device, a display driver circuit receiving a raw input image signal from an external image source and applying a corrected image signal to the display, a display luminance detector generating at least one display device luminance value, and a processing logic unit receiving the at least one display device luminance value and communicating information to the display driver circuit, the display driver circuit using this communicated information to generate a transformation for generating the corrected image signal from the raw input image signal.

Abstract: An emissive pixel device having integrated luminance sensor and a method of operating an emissive pixel device having an integrated luminance or photon flux sensor. Device includes light or photon emitting device, drive circuit generating current to drive light emitting device to predetermined luminance corresponding to an image voltage and applying drive current to light emitting device during frame time, photo sensor that exhibits change in electrical characteristic in response to change in incident photon flux disposed near the light emitting device to intercept measurable photon flux when light emitting device is in emitting state, charge storage device coupled with sensor for accumulating or releasing charges and exhibiting capacitance charge and voltage proportional to the charge at a time; and control circuit controlling charging and discharging of charge storage device in response to changes in electrical characteristics of sensor during at least a portion of the frame time.

Abstract: Information appliance device and method for operating display associated with information appliance. Information appliance includes display device comprising plurality of active-matrix pixels arranged as two-dimensional array, each pixel including a photon emitter, emitter drive circuit receiving input image data for each pixel and generating pixel drive signal intended to produce a corresponding target pixel luminance during frame time, and emitter luminance sensor and measurement circuit that measures electrical parameter indicative of actual luminance of each pixel over portion of measurement display frame time; and display logic coupled to display and receiving pixel luminance related electrical parameter for each pixel and generating correction for application subsequent time period to input image data for each pixel based on difference between target pixel luminance and measured pixel luminance. Photon emitter may be OLED, electroluminescent, plasma or other emissive device in flat panel display.

Abstract: The embodiments of the present invention provide a flat panel display having a plurality of pixels, each comprising a light-emitting device configured to emit light in accordance with a current flowing through the light-emitting device, a transistor coupled to the light-emitting device and configured to provide the current through the light-emitting device, the current increasing with a ramp voltage applied to a control terminal of the transistor, and a switching device configured to switch off in response to the luminance of the light-emitting device having reached a specified level, thereby disconnecting the ramp voltage from the transistor and locking the brightness at the specified level. The ramp voltage is generated in each pixel instead of in peripheral circuits, thereby reducing the number of conducting lines in the display.

Abstract: The embodiments of the present invention provide a color filter integrated with a sensor array and methods of fabricating the same. By integrating the sensor array with the color filter, the overall cost of the display is reduced. Moreover, the integration allows the sensor array to be used like a touch screen for data input. As a further benefit, the integration allows the color filter to serve as a light shield thus eliminating the need for a separate light shield for the sensor array.

Abstract: System, device, and method for receiving or sensing touch or light input to an emissive display such as to a OLED display using the same or different sensors as are used to sense and maintain a pixel luminance. Penlight and touch screen data input system and method for display. A sidelight illuminated display and touch panel input device. Method and device for reading display pixel emission and ambient luminance levels. Emissive display having sensing for luminance stabilization and user light or touch screen input. Method and device for emissive display using shielded or partially shielded sensors. Emissive pixel display device characterized in that photon sensors are disposed within pixels and operated to sense photons emitted by emitter within pixel and ambient photons emitted by sources outside pixel, sensed internally emitted photons being for luminance feedback control and sensed ambient photons being used to detect external light source or sources.