| Patent application number | Description | Published |
|---|
| 20110069096 | Driving System For Active-Matrix Displays - A system is provided for using raw grayscale image data, representing images to be displayed in successive frames, to drive a display having pixels that include a drive transistor and an organic light emitting device. The system defines high and low ranges of raw grayscale image data, and determines whether the raw grayscale image data for each pixel falls within the high range or the low range. Raw grayscale image data that falls within the low range is converted to higher grayscale values, and the pixels are driven with currents corresponding to the higher grayscale values during time periods that are shorter than complete frame time periods. Raw grayscale image data that falls within the high range is converted to higher grayscale values, and the pixels are driven with currents corresponding to the higher grayscale values during time periods that are shorter than complete frame time periods and different from the time periods of the low range image data. When the raw grayscale image data is adjusted according to a preselected gamma curve before using that data to drive the pixels, the high and low ranges may be selected according to how well the gamma curve corrects the raw grayscale image data within the ranges. | 03-24-2011 |
| 20110109299 | Stable Fast Programming Scheme for Displays - A technique for improving the spatial and/or temporal uniformity of a light-emitting display by providing a faster calibration of reference current sources and reducing the noise effect by improving the dynamic range, despite instability and non-uniformity of the transistor devices. A calibration circuit for a display panel having an active area having a plurality of light emitting devices arranged on a substrate, and a peripheral area of the display panel separate from the active area is provided. The calibration circuit includes a first row of calibration current source or sink circuits and a second row of calibration current source or sink circuits. A first calibration control line is configured to cause the first row of calibration current source or sink circuits to calibrate the display panel with a bias current while the second row of calibration current source or sink circuits is being calibrated by a reference current. A second calibration control line is configured to cause the second row of calibration current source or sink circuits to calibrate the display panel with the bias current while the first row of calibration current source or sink circuits is being calibrated by the reference current. | 05-12-2011 |
| 20110109350 | Stable Current Source for System Integration to Display Substrate - A technique to implement a stable and high impedance current sink or source onto a display substrate using a single device. The high output current source or sink circuit includes an input that receives a fixed reference current and provides the reference current to a node in the current source or sink circuit during a calibration operation of the current source or sink circuit. The circuit further includes a first transistor and a second transistor series-connected to the node such that the reference current adjusts the voltage at the node to allow the reference current to pass through the series-connected transistors during the calibration operation. The circuit includes one or more storage devices connected to the node, and an output transistor connected to the node to source or sink an output current from current stored in the one or more storage devices to a drive an active matrix display with a bias current corresponding to the output current. | 05-12-2011 |
| 20110109612 | SHARING SWITCH TFTS IN PIXEL CIRCUITS - A circuit and driving technique to improve the display resolution of an AMOLED display. Sharing of switch transistors between several sub-pixels in the display leads to improved manufacturing yield by minimizing the number of transistors used. The method also allows for conventional sequential scan driving to be used. The circuit includes a shared switch transistor connected between a voltage data line and a shared line that is connected to a reference voltage through a reference voltage transistor, a first pixel including a first light emitting device configured to be current driven by a first drive circuit connected to the shared line through a first storage device, a second pixel including a second light emitting device configured to be current driven by a second drive circuit connected to the shared line through a second storage device, and a reference current line configured to apply a bias current to the first and second drive circuits. | 05-12-2011 |
| 20110128262 | HIGH RESOLUTION PIXEL ARCHITECTURE - A high resolution pixel using organic light emitting devices (OLEDs) in a staggered arrangement to increase aperture ratio is disclosed. The arrangement may be used with both bottom and top emission type pixels. The arrangement includes a first organic light emitting device emitting light of a first color. A second organic light emitting device emitting light of a second color is located in a bottom row under the first organic light emitting device. A third organic light emitting device emitting light of a third color is located in a top row with the first organic light emitting device. | 06-02-2011 |
| 20110130981 | SYSTEM AND METHODS FOR AGING COMPENSATION IN AMOLED DISPLAYS - Methods and systems to provide baseline measurements for aging compensation for a display device are disclosed. An example display system has a plurality of active pixels and a reference pixel. Common input signals are provided to the reference pixel and the plurality of active pixels. The outputs of the reference pixel is measured and compared to the output of the active pixels to determine aging effects. The display system may also be tested applying a first known reference current to a current comparator with a second variable reference current and the output of a device under test such as one of the pixels. The variable reference current is adjusted until the second current and the output of the device under test is equivalent of the first current. The resulting current of the device under test is stored in a look up table for a baseline for aging measurements during the display system operation. The display system may also be tested to determine production flaws by determining anomalies such as short circuits in pixel components such as OLEDs and drive transistors. | 06-02-2011 |
| 20110134157 | SYSTEM AND METHODS FOR POWER CONSERVATION FOR AMOLED PIXEL DRIVERS - A circuit and method to improve energy conservation of an AMOLED display. The display includes a matrix of pixels each having an organic light emitting device coupled to a drive transistor. The brightness of the light emitting device is controlled by a programming voltage applied to the gate of the drive transistor. The supply voltage to the drive transistor is adjusted to different levels based on the required brightness of the pixel. Since the drive transistor operates in saturation mode, especially when maximum brightness is desired, the supply voltage may be reduced while maintaining the same brightness level. | 06-09-2011 |
| 20110191042 | SYSTEM AND METHODS FOR EXTRACTING CORRELATION CURVES FOR AN ORGANIC LIGHT EMITTING DEVICE - A system and method for determining and applying characterization correlation curves for aging effects on an organic light organic light emitting device (OLED) based pixel is disclosed. A first stress condition is applied to a reference pixel having a drive transistor and an OLED. An output voltage based on a reference current is measured periodically to determine an electrical characteristic of the reference pixel under the first predetermined stress condition. The luminance of the reference pixel is measured periodically to determine an optical characteristic of the reference pixel. A characterization correlation curve corresponding to the first stress condition including the determined electrical and optical characteristic of the reference pixel is stored. Characterization correlation curves for other predetermined stress conditions are also stored based on application of the predetermined stress conditions on other reference pixels. The stress condition of an active pixel is determined and a compensation voltage is determined by correlating the stress condition of the active pixel with the curves of the predetermined stress conditions. | 08-04-2011 |
