An active TFT circuit structure with current scaling function is disclosed, which includes a current source, a data line, a scan line, a direct current voltage source, capacitors and four transistors, wherein the capacitors form a cascade structure. During the ON-state, the two of the transistors are turn-on based on the voltage provided by the scan line, so that the data current provided by the current source flows through the data line-and the transistor which is one of the opened transistors,...

A potential on a control terminal of a driver transistor is controlled and a drive current corresponding to the potential is supplied to an organic electroluminescence element. A drive controlling transistor is inserted between the driver transistor and the organic electroluminescence element and the drive current is switched on and off by the drive controlling transistor. A short-circuiting transistor is provided which controls whether or not the driver transistor is to be diode-connected. A se...

A method of optimizing lifetime of an OLED display element and an OLED display element with optimized lifetime for possible use in a tiled display, while maintaining light output are described. It compensates an OLED operating parameter such as supply voltage and/or on-time of the operating current based on at least one environmental factor which affects aging and on at least one operating factor which is indicative of aging, e.g. by determining the brightness of an OLED display element. To opti...

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 pre...

A LED driving device includes a plurality of LEDs, a voltage detecting circuit, and a current switching circuit. When the voltage detecting circuit detects the different voltage level of power source without coupling to a filtering capacitor, it sends a signal to the current switching circuit and then the current switching circuit is automatically activated to electrically rearrange the configuration of LEDs with a predetermined current value by lighting the greatest number of LEDs that improvin...

A circuit apparatus for driving a light emitting diode with a low voltage is disclosed. The circuit apparatus includes an NPN transistor, a PNP transistor, a capacitor connected to a base of the NPN transistor, a resistor connected to a contact point between the base of the NPN transistor and the capacitor and connected to the power, and an inductor connected to the power ground and a collector of the PNP transistor.

A circuit for driving light emitting diodes with a precise amount of current in response to an input pulse is disclosed. The input pulse drives a transistor into saturation, and the collector current of this transistor is increased in value through the use of two cascaded multiplying current mirrors. The second current mirror directly drives the light emitting diodes.

A luminescent display device is disclosed. The luminescent display device is comprised of an array of pixels, a first driving chip and a second driving chip. The array of pixels is comprised of columns and rows of pixels. The first driving chip is connected a first pixel of the array of pixels, and the second driving chip is connected to a second pixel of the array of pixels. The second pixel is adjacent to the first pixel. The first driving chip is not connected to all pixels in a row of the at...

A pixel and a light emitting display including the pixel. The pixel includes first and second organic light emitting diodes (OLEDs), a driving circuit commonly connected to the plurality of OLEDs to drive the first and second OLEDs, a switching circuit connected between the first and second OLEDs and the driving circuit to sequentially control the driving of the first and second OLEDs using first and second emission control signals, and a reverse bias circuit for selectively applying a reverse b...

A light emitting diode (LED) circuit includes first and second terminals, a forward circuit including a number of LEDs electrically connected in series, and a forward steering diode electrically connected in series with the LEDs. The series combination of the forward steering diode and the LEDs is electrically connected between the first and second terminals, and is structured to conduct current in a first direction with respect to the first and second terminals in order to illuminate the LEDs. ...