Abstract: A pixel driver circuit having only three conductive layers is described. The pixel driver circuit comprises a vertical driver transistor (26) spanning said three conductive layers, wherein a first of said conductive layers (22) on a first side of a middle conductive layer (32) provides a first source-drain connection (52) of said driver transistor, wherein a third of said conductive layers (34) on the opposite side of said middle conductive layer to said first conductive layer provides a gate connection (54) for said vertical driver transistor, and wherein said middle conductive layer provides a second source-drain connection (50) for said vertical driver transistor. The circuit also comprises a lateral switching transistor (30) with source-drain connections (44,46) in one of said three conductive layers.

Abstract: We describe a lighting tile having a substrate bearing an electrode structure, the electrode structure comprising: a plurality of electrically conductive tracks disposed over said substrate; and an electrical connection region connecting to said plurality of tracks; wherein the height of said tracks tapers away from said connection region to compensate for a reduction in luminance from said lighting tile array from the electrical connection region which arises from a non-uniform voltage drop which appears along the tracks in use. Advantageously the tracks are fabricated by electroplating: then, as the rate of deposition is determined by the voltage drop along a track during plating, the height of the deposited tracks, and therefore their resistance, will match the profile required in operation to compensate for the reduction in luminance which would otherwise occur.

Abstract: A pixel driver circuit having only three conductive layers is described. The pixel driver circuit comprises a vertical driver transistor (26) spanning said three conductive layers, wherein a first of said conductive layers (22) on a first side of a middle conductive layer (32) provides a first source-drain connection (52) of said driver transistor, wherein a third of said conductive layers (34) on the opposite side of said middle conductive layer to said first conductive layer provides a gate connection (54) for said vertical driver transistor, and wherein said middle conductive layer provides a second source-drain connection (50) for said vertical driver transistor. The circuit also comprises a lateral switching transistor (30) with source-drain connections (44,46) in one of said three conductive layers.

Abstract: We describe a lighting tile having a substrate bearing an electrode structure, the electrode structure comprising: a plurality of electrically conductive tracks disposed over said substrate; and an electrical connection region connecting to said plurality of tracks; wherein the height of said tracks tapers away from said connection region to compensate for a reduction in luminance from said lighting tile array from the electrical connection region which arises from a non-uniform voltage drop which appears along the tracks in use. Advantageously the tracks are fabricated by electroplating: then, as the rate of deposition is determined by the voltage drop along a track during plating, the height of the deposited tracks, and therefore their resistance, will match the profile required in operation to compensate for the reduction in luminance which would otherwise occur.

Abstract: We describe a lighting tile having a substrate bearing an electrode structure, the electrode structure comprising: a plurality of electrically conductive tracks disposed over said substrate; and an electrical connection region connecting to said plurality of tracks; wherein the height of said tracks tapers away from said connection region to compensate for a reduction in luminance from said lighting tile array from the electrical connection region which arises from a non-uniform voltage drop which appears along the tracks in use. Advantageously the tracks are fabricated by electroplating: then, as the rate of deposition is determined by the voltage drop along a track during plating, the height of the deposited tracks, and therefore their resistance, will match the profile required in operation to compensate for the reduction in luminance which would otherwise occur.

Abstract: An apparatus such as a touch screen display includes correlated emitter-detector pairs for determining the amount of electromagnetic radiation received at a detector from its paired emitter. The apparatus comprises an array of emitters operable to emit electromagnetic radiation, an array of detectors for detecting the electromagnetic radiation, and drive control circuitry configured to control the array of emitters so that they emit pulses of electromagnetic radiation. The amplitude of the pulses is modulated using mutually orthogonal binary vectors such as a Paley construction of the Hadamard matrix. Each emitter has a different vector associated with it. Detection circuitry is provided to detect the electromagnetic radiation reaching each particular detector in the array of detectors using the mutually orthogonal binary vector associated with the correlated emitter to produce a correlation between particular emitter-detector pairs. The arrangement can discriminate between near field and touching objects.

Abstract: This invention relates to active matrix OLED (Organic Light Emitting Diode) displays, in particular to display panels with integrated negative capacitance circuits and to active capacitance compensation. We describe an active matrix OLED display comprising a glass panel bearing a plurality of lines of OLED pixels, each with an associated active matrix driver circuit having a programming connection for programming a brightness of the associated OLED, programming connections of a line of pixels being connected to a programming line of said display, and wherein said active matrix OLED display further comprises a plurality of capacitors on said glass panel, each having a first plate connected to an end of a respective said programming line and having a second plate for connecting to a negative capacitor circuit to compensate for a capacitance of said programming line.

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: 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: An apparatus such as a touch screen display includes correlated emitter-detector pairs for determining the amount of electromagnetic radiation received at a detector from its paired emitter. The apparatus comprises an array of emitters operable to emit electromagnetic radiation, an array of detectors for detecting the electromagnetic radiation, and drive control circuitry configured to control the array of emitters so that they emit pulses of electromagnetic radiation. The amplitude of the pulses is modulated using mutually orthogonal binary vectors such as a Paley construction of the Hadamard matrix. Each emitter has a different vector associated with it. Detection circuitry is provided to detect the electromagnetic radiation reaching each particular detector in the array of detectors using the mutually orthogonal binary vector associated with the correlated emitter to produce a correlation between particular emitter-detector pairs. The arrangement can discriminate between near field and touching objects.

Abstract: This invention relates to active matrix OLED (Organic Light Emitting Diode) displays, in particular to display panels with integrated negative capacitance circuits and to active capacitance compensation. We describe an active matrix OLED display comprising a glass panel bearing a plurality of lines of OLED pixels, each with an associated active matrix driver circuit having a programming connection for programming a brightness of the associated OLED, programming connections of a line of pixels being connected to a programming line of said display, and wherein said active matrix OLED display further comprises a plurality of capacitors on said glass panel, each having a first plate connected to an end of a respective said programming line and having a second plate for connecting to a negative capacitor circuit to compensate for a capacitance of said programming line.

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.