Abstract: An organic light emitting diode (OLED)/polymer OLED (PLED) displays and operation with a precharge latency. Particularly, precharging operation of such a display device with a precharge switch latency. According to the operation, a capacitive aspect of a display element is precharged, and the display element is activated so as to conducting a current therethrough. The precharging is terminated after the activation of the display element. Then a current is supplied and conducted through the display element for exposure of the display element. In this operation, a precharge droop that may occur during the transition between precharge and exposure can be avoided or minimized.

Abstract: An apparatus to determine and apply a voltage to precharge current-driven elements in a matrix. During ordinary scan cycles, a conduction voltage is sensed while the elements conduct a selected current. While not conducting the selected current, the sensed conduction voltage is averaged with other conduction voltages, and based on the averaged voltage a precharge voltage is provided during a precharge period of the scan cycle.

Abstract: A method to determine and apply a voltage to precharge current-driven elements in a matrix. During ordinary scan cycles, a conduction voltage is sensed while the elements conduct a selected current. While not conducting the selected current, the sensed conduction voltage is averaged with other conduction voltages, and based on the averaged voltage a precharge voltage is provided during a precharge period of the scan cycle.

Abstract: A system for providing balanced currents at locations in devices requiring accurate, matched and repeatable current sources, for example visual displays having arrays of light-emitting sources. In one embodiment, the system provides closely balanced currents flowing through column drivers located at or near end regions of a display area. The system allows for more closely matching currents at adjacent columns in a device such as a visual display, wherein the currents are driven by separate driver circuits, thereby eliminating discontinuity in brightness across the entire display area and providing higher quality visual display devices. Another embodiment provides closely balanced currents flowing through column drivers located at or near end regions of a display area. The system additionally allows for balancing currents at adjacent columns or regions throughout the device.

Abstract: A method of predicting current boost levels and applying them to precharge current-driven elements in a matrix, and a method of manufacturing devices for this purpose. Elements are driven during successive scan cycles, each having a precharge period and an exposure period. One or more conduction voltages are sensed while an element conducts a selected current, either during a calibration cycle or during an exposure. A correct boost current is predicted from the conduction voltage(s) based upon other parameters including column capacitance, which may be determined upon manufacture, and the predicted boost current is then applied to matrix elements.

Abstract: An apparatus for generating and providing a stable reference voltage to a boost regulator. The apparatus comprises a clamping circuit that is configured to receive a constant voltage and a variable voltage. The clamping circuit is further configured to generate the reference voltage based on the constant voltage and variable voltage. The clamping circuit provides the reference voltage to the boost regulator at a level that is at least sufficient to cause the boost regulator to output a non-zero voltage.

Abstract: A method and apparatus for adapting and applying current boost levels to precharge current-driven elements in a matrix, and a method to make devices for this purpose. Elements are driven during successive scan cycles, each having a precharge period and an exposure period. One or more conduction voltages are sensed while an element conducts a selected exposure current, with early samples taken nearer the beginning of exposures and late samples taken nearer the end. Charge delivered during the precharge period is adjusted to reduce differences between early and late voltage samples.

Abstract: A method and system for controlling a voltage used for precharging current-driven elements in a matrix, and a method of manufacturing a device to perform this function. Elements are driven during successive scan cycles, each having a precharge period and an exposure period. The elements conduct current during conduction periods, which typically have variable length within exposure periods. Conduction voltages are sensed at earlier times (e.g., near the beginning) and later times (e.g., near the end) within conduction periods. A precharge voltage is adapted based on a comparison of the earlier and later sensed conduction voltages, typically so as to reduce any average difference and thereby cause the voltage during exposure to be consistent.

Abstract: A method of providing balanced currents at locations in devices requiring accurate, matched and repeatable current sources, for example visual display devices having arrays of light-emitting sources. In one embodiment, the method provides closely balanced currents flowing through column drivers located at or near end regions of a display area portion of a visual display device. An additional embodiment of the method allows for balancing currents at adjacent columns or regions throughout the display areas of a visual display device.

Abstract: A method of providing balanced currents at locations in devices requiring accurate, matched and repeatable current sources, for example visual displays having arrays of light-emitting sources. In one embodiment, the method provides closely balanced currents flowing through column drivers located at or near end regions of a display area. The method allows for more closely matching currents at adjacent columns in a device such as a visual display, wherein the currents are driven by separate driver circuits, thereby eliminating discontinuity in brightness across the entire display area and providing higher quality visual display devices. Another embodiment provides closely balanced currents flowing through column drivers located at or near end regions of a display area. The method additionally allows for balancing currents at adjacent columns or regions throughout the device.

Abstract: A pulse width modulation driver for an organic light emitting diode display. One embodiment of a video display comprises a voltage driver for providing a selected voltage to drive an organic light emitting diode in a video display. The voltage driver may receive voltage information from a correction table that accounts for aging, column resistance, row resistance, and other diode characteristics.

Abstract: A pulse width modulation driver for an organic light emitting diode display. One embodiment of a video display comprises a voltage driver for providing a selected voltage to drive an organic light emitting diode in a video display. The voltage driver may receive voltage information from a correction table that accounts for aging, column resistance, row resistance, and other diode characteristics.

Abstract: An apparatus for establishing and applying a voltage to precharge current-driven elements in a matrix. During ordinary scan cycles, a conduction voltage is sensed while the elements conduct a selected current. One or more such sensed conduction voltages are combined to provide a basis for a precharge voltage. Conduction and transient errors are determined, and are compensated for by offsetting the final precharge voltage from the conduction voltage basis. The final precharge voltage is provided to one or more columns during a precharge period of the scan cycle.

Abstract: A circuit for increasing the voltage/current level of a signal to drive a power transistor from a low voltage input. The gate drive circuit comprises a voltage multiplier for increasing the voltage level of a low voltage input signal, a level shifter for shifting the voltage level of a logic signal to a level relative to a voltage signal produced by the voltage multiplier, and a source follower, connected to the level shifter, for increasing the current of the increased voltage, level shifted output signal of the level shifter. The resulting multiplied, shifted, and increased current signal can be used to drive a power transistor.

Abstract: A method and apparatus to calibrate an LED matrix display such that a driver will provide a proper precharge voltage to LED elements within the display during a scan period. A current is driven through a calibration element, and a voltage reflecting the steady-state element voltage is measured and stored as a calibration value. A processor controls whether to precharge during the calibration cycle, and determines when the calibration cycle is completed. During subsequent normal scans, a driver applies a voltage based on the stored calibration value to rapidly precharge parasitic capacitance associated with a display element to a proper value, and also drives a selected current through the device.