Abstract: An organic electroluminescent device comprising: a transparent substrate; a first electrode disposed over the substrate for injecting charge of a first polarity; a second electrode disposed over the first electrode for injecting charge of a second polarity opposite to said first polarity; an organic light-emitting layer disposed between the first and the second electrode, wherein the second electrode is reflective, the first electrode is transparent or semi-transparent, and one or more intermediate layers of dielectric material with a refractive index greater than 1.

Abstract: A method of driving an electro-optic display comprising providing a current source, digitally modulating the current source and generating a modulated digital signal, and converting the modulated digital signal into an effective analog drive signal so that the display pixels receive an effective analog drive current, wherein the internal capacitance of the electro-optic display smooths the digitally modulated signal and generates the effective analog drive signal.

Abstract: This invention relates to methods, apparatus, and computer program code for driving an active matrix display, in particular an organic light emitting diode (OLED) display, with reduced power consumption.

Abstract: A current matching control apparatus for matching a plurality of current sources and a plurality of current sinks, the plurality of current sinks having a drive current value controlled by a drive processor in accordance with a reference control current and wherein each output of the plurality of current sinks are connected to a common output node; a feedback circuit having an input connected to the common output node and an output connected to the drive processor, wherein the feedback circuit is arranged to match a voltage at the common output node to a reference voltage by communicating a signal to the drive processor to adjust the reference control current.

Abstract: An OLED lighting element comprises a substrate bearing an OLED structure extending laterally over said substrate and sandwiched between first and second electrode layers. The first electrode layer defines a plurality of electrically conductive tracks and said second electrode layer comprises a substantially continuous electrically conducting layer. The OLED lighting element has an electrical bus-bar connected to said electrically conductive tracks extending substantially completely along the or each lateral edge of said lighting element. The electrically conductive tracks run in a radial direction from a laterally central location within said lighting element towards said bus-bar along said lateral edges of said lighting element. A said track subdivides into a plurality of tracks with increasing distance from said central location. This arrangement makes more efficient use of the conductive tracks.

Abstract: This invention generally relates to organic electronic devices and to methods for their fabrication. More particularly we will describe organic thin film transistor (TFT) structures and their fabrication. An organic electronic device, the device comprising: a substrate supporting a first electrode; a spacer structure over said substrate; a second electrode over said spacer structure and at a height above said first electrode; and a layer of organic semiconducting material over said first and second electrodes to provide a conducting channel between said first and second electrodes; and wherein a majority of said first electrode is laterally positioned to one side of said channel and a majority of said second electrode is laterally positioned to the other side of said channel.

Abstract: We describe a method of driving an OLED display. The OLED display comprises a plurality of pixel driver circuits on chiplets, each pixel driver circuit comprising an output transistor for driving a first connection of an associated OLED pixel. A cascode transistor on the chiplet is coupled between the output transistor and the first connection of said associated OLED pixel. A power supply is provided to the chiplet, defining a chiplet voltage range. A second connection of the associated OLED pixel is connected to an OLED voltage outside said chiplet voltage range. The OLED pixel is then driven using the pixel driver circuit on the chiplet over an OLED voltage range greater than said chiplet voltage range. In some preferred embodiments a drain connection of the cascode transistor is set at a voltage below a ground or negative (Vss) power supply to a chiplet.

Abstract: An organic light emissive device comprising: a first electrode; a second electrode; and an organic light emissive region between the first and second electrodes comprising an organic light emissive material which has a peak emission wavelength, wherein at least one of the electrodes is transparent and comprises a composite of a charge injecting metal and another material which is codepositable with the charge injecting metal, the other material having a different refractive index to that of the charge injecting metal and wherein the other material has a lower degree of quenching at the peak emission wavelength than the charge injecting metal whereby quenching of excitons by the at least one electrode is reduced, the charge injecting metal comprising either a low work function metal having a work function of no more than 3.5 eV or a high work function metal having a work function of no less than 4.5 eV.

Abstract: A pixel driver architecture for an active matrix OLED display, the pixel driver architecture comprising a voltage-programmed master pixel programming circuit, and a first plurality of current-programmed slave pixel driver circuits, each coupled to said master pixel programming circuit.

Abstract: This invention relates to pixel driver circuits for active matrix optoelectronic devices, in particular OLED (organic light emitting diodes) displays. We describe an active matrix optoelectronic device having a plurality of active matrix pixels each said pixel including a pixel circuit comprising a thin film transistor (TFT) for driving the pixel and a pixel capacitor for storing a pixel value, wherein said TFT comprises a TFT with a floating gate.

Abstract: Display driver circuits are described for driving organic light emitting diode displays, particularly passive matrix displays with greater efficiency. Display driver control circuitry (506) comprises a frame memory interface (505) for reading data from a frame memory (504) for presentation on a passive matrix OLED display. A blank line identifier (507) identifies one or more substantially blank rows of pixels defined by the data in the frame memory and the control circuitry (506) skips past these rows when the passive matrix display is addressed. When blank lines are skipped the apparent brightness of the remaining lines increases and thus preferably the control circuitry includes a power controller (505) for reducing a power supply to the display in proportion to the number of skipped lines. The invention is particularly suited to a display driver providing a controlled current drive.

Abstract: An organic light emissive device comprising: a first electrode; a second electrode; and an organic light emissive region between the first and second electrodes comprising an organic light emissive material which has a peak emission wavelength, wherein at least one of the electrodes is transparent and comprises a composite of a charge injecting metal and another material which is codepositable with the charge injecting metal, the other material having a different refractive index to that of the charge injecting metal and wherein the other material has a lower degree of quenching at the peak emission wavelength than the charge injecting metal whereby quenching of excitons by the at least one electrode is reduced, the charge injecting metal comprising either a low work function metal having a work function of no more than 3.5 eV or a high work function metal having a work function of no less than 4.5 eV.

Abstract: An organic light emissive device comprising: a first electrode; a second electrode; and an organic light emissive region between the first and second electrodes comprising an organic light emissive material which has a peak emission wavelength, wherein at least one of the electrodes is transparent and comprises a composite of a charge injecting metal and another material which is codepositable with the charge injecting metal, the other material having a different refractive index to that of the charge injecting metal and wherein the other material has a lower degree of quenching at the peak emission wavelength than the charge injecting metal whereby quenching of excitons by the at least one electrode is reduced, the charge injecting metal comprising either a low work function metal having a work function of no more than 3.5 eV or a high work function metal having a work function of no less than 4.5 eV.

Abstract: A display has a plurality of organic light emitting diode (OLED) pixels each with an associated pixel driver circuit, a plurality of select lines and a plurality of data lines. Each pixel driver circuit is coupled to a select line and to a data line.

Abstract: An organic electroluminescent device comprising: a substrate; a first electrode disposed over the substrate for injecting charge of a first polarity; a second electrode disposed over the first electrode for injecting charge of a second polarity opposite to said first polarity; an organic light emitting layer disposed between the first and the second electrode, the second electrode being transparent to light emitted by the light emitting layer; a glass or transparent plastic encapsulant disposed over, and spaced apart from, the second electrode, defining a cavity therebetween; and a cavity filling material disposed within the cavity, the cavity filling material extending from a bottom side of the cavity to a top side of the cavity, the cavity filling material having an optical structure disposed therein.

Abstract: An organic light emitting diode (OLED) display device is described, the display device having a plurality of pixels each comprising at least two sub-pixels of different types, a first sub-pixel type comprising an OLED device including a first type of OLED material and a second sub-pixel type comprising an OLED device including a second type of OLED material, and wherein at least one of said first and second types of sub-pixel comprises a plurality of series-connected OLED devices. Employing series-connected sub-pixels where different types of OLED material are used for a display such as a color, active matrix OLED display facilitates balancing sub-pixel drive voltages and hence enables the production of display devices with improved efficiency.

Abstract: A light-emissive display comprising a substrate, a first electrode layer disposed over the substrate, a light-emissive layer disposed over the first electrode layer, and a second electrode layer disposed over the light-emissive layer, wherein the light-emissive layer is patterned to provide a plurality of discrete light-emissive regions, each discrete light-emissive region being a pixel, or a sub-pixel, of the light-emissive display, and wherein the first electrode layer and/or the second electrode layer comprises a plurality of electrodes, each electrode comprising at least two sub-electrodes associated with each discrete light-emissive region.

Abstract: A device comprising an organic light emitting diode coupled to a cavity, said cavity containing an emitting species, said device being arranged such that light emitted from said organic light emitting diode is at least partially absorbed by the emitting species and re-emitted from the emitting species. The device may be arranged such that the emitting species acts as the gain media of a laser, and the organic light emitting diode may be arranged to pump the emitting species. Also provided is method of generating light, said method comprising: coupling an organic light emitting diode to a cavity, said cavity containing an emitting species, said organic light emitting diode and said cavity being arranged such that light emitted from said organic light emitting diode is at least partially absorbed by the emitting species; operating said organic light emitting diode to emit light which is at least partially absorbed by the emitting species; and re-emitting light from the emitting species.

Abstract: An organic electroluminescent device cfomprising: a transparent substrate; a first electrode disposed over the substrate for injecting charge of a first polarity; a second electrode disposed over the first electrode for injecting charge of a second polarity opposite to said first polarity; an organic light-emitting layer disposed between the first and the second electrode, wherein the second electrode is reflective, the first electrode is transparent or semi-transparent, and one or more intermediate layers of dielectric material with a refractive index greater than 1.

Abstract: A pixel driver circuit for active matrix driving of an organic light emitting diode (OLED) comprises a drive transistor having a current path connected to a first voltage supply line at one end and to an OLED at the other end and a gate terminal connected to a storage element connected between gate and source of the drive transistor to memorize a drive signal for the drive transistor under the control of a first switch transistor having a gate connection to a first selection line and a current path connected between gate and drain of the drive transistor, and a second switch transistor having a gate connection to a second selection line, wherein the second switch transistor has a current path connected to the data line at one end and a node at the other end located between the drive transistor and the OLED.