Abstract: An active matrix display device comprises an array of display pixels, with each pixel comprising an EL display element, a light-dependent device for detecting the brightness of the display element and a drive transistor circuit for driving a current through the display element. The drive transistor is controlled in response to the light-dependent device output so that ageing compensation can be implemented. The light-dependent device is located laterally of the area of light emitting material of the EL display element. In this way, the light-dependent device does not cause step coverage problems and can be integrated into the pixel layout without affecting the pixel aperture. Furthermore, the light dependent device can extend alongside the full length of the area of light emitting material so that it receives light input from a large part of the display element area.

Abstract: The pixels of an active matrix display device have a current-driven light emitting display element, a drive transistor for driving a current through the display element, a storage capacitor for storing a pixel drive voltage to be used for addressing the drive transistor, a light-dependent device for detecting the brightness of the display element, and driver circuitry for providing data signals to the pixel external to the pixel array. This provides a pixel with optical feedback to compensate for display element ageing. The driver circuitry has a processing means for processing the feedback brightness signals and derives from them a threshold voltage for the drive transistor of the pixel as well as information relating to the performance of the display element, for ageing compensation.

Abstract: An EL device comprising a substrate (11), a light emissive structure comprising three series connected LEDs on the substrate (LED 1, 2, 3). Considering the diode LED1, it comprises organic light emissive material disposed (16-1) between an underlying ITO anode (12-1) and an overlying cathode (17-1) that is electrically connected in series to the underlying anode (12-2) of the diode LED2 through the thickness of the organic light emissive material (16-1). The connection can be made by using a wetting agent to prevent the organic light emissive material disposed (16-1) covering contact region (19-1) on the anode (12-2) so that the overlying cathode (17-1) can make a series connection with the underlying anode (12-2).

Abstract: An active matrix display device has pixels each with a light-sensitive device (84) for optical feedback functions. Each pixel has a light blocking structure (100) formed from the thin film layers of the display substrate in the proximity of the light-sensitive device (84) and substantially at the level of an input surface of the light sensitive device. This structure prevents the passage of light (g) to the light sensitive device from a substantially lateral direction.

Abstract: An active matrix LED display device uses optical feedback for controlling the pixel drive transistors (2). The LED display elements are controlled to provide a pulsed output, and the optical feedback element (66,68) is controlled cyclically such that, for constant illumination of the optical feedback element (66,68) during a cycle, there is a substantially zero net output charge flow. This arrangement uses pulsed light output, and arranges the optical feedback to operate only in response to a corresponding pulsed light input. In this way, ambient light, which will be uniform over the time period of the cycle of operation, will not influence the optical feedback system. In this way, the system is not influenced by ambient light conditions.

Abstract: In the manufacture of an electronic device such as an active matrix display, a vertical amorphous PIN photodiode or similar thin-film diode (D) is advantageously integrated with a polysilicon TFT (TFT1, TFT2) in a manner that permits a good degree of optimization of the respective TFT and diode properties while being compatible with the complex pixel context of the display. High temperature processes for making the active semiconductor film (10) of the TFT more crystalline than an active semiconductor film (40) of the diode and for forming the source and drain doped regions (s1,s2, d1,d2) of the TFT are carried out before depositing the active semiconductor film (40) of the diode. Thereafter, the lateral extent of the diode is defined by etching while protecting with an etch-stop film (30) an interconnection film (20) that can provide a doped bottom electrode region (41) of the diode as well as one of the doped regions (s2, g1) of the TFT.

Abstract: The pixels of an active matrix display device have a current-driven light emitting display element, a drive transistor for driving a current through the display element, a storage capacitor for storing a pixel drive voltage to be used for addressing the drive transistor, a light-dependent device for detecting the brightness of the display element, and driver circuitry for providing data signals to the pixel external to the pixel array. This provides a pixel with optical feedback to compensate for display element ageing. The driver circuitry has a processing means for processing the feedback brightness signals and derives from them a threshold voltage for the drive transistor of the pixel as well as information relating to the performance of the display element, for ageing compensation.

Abstract: An active plate (2) for an active matrix display device (16), the active plate (2) comprising a substrate (4), a pixel area (6) and an adjacent drive circuit area (8). Both areas include polycrystalline silicon material formed by a process in which a metal is used to enhance the crystallization process (MIC poly-Si), but only the MIC poly-Si in the drive circuit area (8) is subjected to an irradiation process using an energy beam (10). TFTs are fabricated with MIC poly-Si which have leakage currents in the off state sufficiently low for them to be acceptable for use as switching elements in the pixel area of matrix display devices. As only the drive circuit area (8) need be irradiated to provide poly-Si having the desired mobility, the time taken by the irradiation process can be significantly reduced.

Abstract: A display device, for example a liquid crystal display device (1), and driving method are provided that avoid the need to provide the display device with display data (e.g. video) containing individual display settings for each pixel. The display device comprises an array of pixels (21-36, 71a-79d, 121-136) and an array of processing elements (41-48, 71-79, 141-148), each processing element being associated with a respective pixel or group of pixels. The processing elements (41-48, 71-79, 141-148) perform processing of compressed input display data at pixel level. The processing elements (41-48, 71-79, 141-148) decompress the input data to determine individual pixel settings for their associated pixel or pixels. The processing elements (41-48, 71-79, 141-148) then drive the pixels (21-36, 71a-79d, 121-136) at the individual settings. A processing element may interpolate pixel settings from input data allocated to itself and one or more neighbouring processing elements.

Abstract: A method of manufacturing an electronic device comprising a thin film transistor (42), comprises forming a hydrogen-containing layer (22) over a semiconductor layer (10;20), irradiating the hydrogen-containing layer so as to hydrogenate the semiconductor layer, and then forming electrodes (24;26,28) over the semiconductor layer. A short diffusion length and direct path is provided for the hydrogen thus allowing rapid hydrogenation of the semiconductor layer using relatively few, high-fluence laser pulses. The supporting substrate (12) is not heated significantly making the method particularly useful for TFTs on polymer substrates. Crystallisation and hydrogenation of the semiconductor layer can be executed in the same irradiation step.

Abstract: A colour active matrix electroluminescent (EL) display device has an array of pixels (10) comprising sets of red, green and blue emitting pixels, each of which pixels comprises an EL display element (20), a drive transistor (22) for driving a current through the display element, a storage capacitor (24) for storing a voltage used for addressing the drive transistor, and a discharge photosensitive element (40, 42) for discharging the storage capacitor in dependence on the light output of the display element. The discharge photosensitive elements (42) in the set of blue pixels comprise lateral photosensitive thin film devices, such as lateral thin film transistors or gated or ungated lateral photodiode devices, while the discharge photosensitive elements (40) in the set of red pixels, and preferably the set of green pixels as well, comprise vertical p i n photodiodes (40).

Abstract: A data input system is described comprising a surface 10, pen 12 and a plurality of transducers 14. The surface has a structure 10 such that when the pen 12 is moved across the structure 10, vibration is generated. This is detected by the transducers and the position of the pen 12 on the surface 10 is calculated. In the preferred embodiment of the invention the structure of the surface 10 varies across the surface 10. This means vibration signal waveforms may be associated with specific regions of the surface making identification of the pen location easier.

Abstract: In an active matrix electroluminescent display device having an array of pixels, a drive transistor and an electroluminescent display element in each pixel are connected in series between a power line for supplying or drawing a controllable current to or from the display element and a common potential line. The power line and the common potential line each comprise a sheet electrode shared among all pixels of the array. In this arrangement, sheet electrodes are used both for the current supply to the EL display element and the current sink. This reduces considerably the line resistance.

Abstract: A method of manufacturing an electronic device comprising a bottom-gate TFT (12) is provided, the method comprising the steps of: forming a doped amorphous silicon gate layer (26?) on a substrate, the gate layer defining a gate (26), forming a gate insulating layer (32) over the gate, forming an amorphous silicon active layer (28?) over the gate insulating layer and overlying at least part of the gate, and annealing the amorphous silicon active layer to form a polysilicon active layer (28). A thinner gate insulating layer can be used giving a TFT having a low threshold voltage.

Abstract: A matrix array device, for example, an active matrix display device, image sensor, or the like, comprises a matrix circuit (12, 14, 16, 18) carried on a flexible substrate (20) which circuit includes an array of semiconductor devices (12), such as TFTs, occupying discrete areas. Selected regions of the substrate (20) away from the semiconductor devices (12) are formed as areas of weakness to encourage flexing of the substrate to occur preferentially at those regions upon bending of the device and so reduce the risk of damage to the semiconductor devices. The regions, for example, may comprise lines of weakness (50, 52) extending between the semiconductor devices and may be formed by localized thinning of the substrate or by treating the substrate material to modify its stiffness at predetermined areas.

Abstract: A matrix array display device has an array of pixels on a substrate which each have a display element, such as an electroluminescent display element. An associated control circuit including a storage capacitor and a light sensing element are connected thereto for regulating charge stored on the capacitor and responsive, for example, to light emitted from the display element so as to regulate operation of the display element. The light sensing elements include thin film semiconductor devices each having a strip of semiconductor material with laterally-spaced, doped, contact regions and the associated storage capacitor is formed by a conductive layer extending substantially transversely of the strip over one contact region with intervening dielectric material. A predetermined relationship between the storage capacitor and photosensitive device characteristics is then ensured even though dimensional variations in component layers may occur due to manufacturing tolerances.

Abstract: A method of fabricating an electronic device comprising a thin-film transistor, which addresses a problem of increased off-state current and reduced carrier mobility in self-aligned thin-film transistors. According to the method, a gate layer (2,46) is etched back underneath a mask layer (20,48). Following an implantation step using the mask layer as an implantation mask, the etch-back exposes implant damage which is then annealed by an energy beam (42).

Abstract: A display device comprises an array of display pixels, each pixel comprising a first and second display elements (12, 14). The first element I(12) s drivable between at least two transmission states, for example an LC cell. The first display element (12) overlyies the second display element (14) which is an electroluminescent display element. The first display element (12) can be used when the ambient light conditions are sufficient, and enables an electroluminescent (EL) element to be used when the light conditions are not sufficient. By providing the display element over each other, the resolution of each is not impaired. The first display element (12) can then be driven to a transparent state when using the EL element beneath.

Abstract: A data input system is described comprising a surface 10, pen 12 and a plurality of transducers 14. The surface has a structure 10 such that when the pen 12 is moved across the structure 10, vibration is generated. This is detected by the transducers and the position of the pen 12 on the surface 10 is calculated. In the preferred embodiment of the invention the structure of the surface 10 varies across the surface 10. This means vibration signal waveforms may be associated with specific regions of the surface making identification of the pen location easier.

Abstract: A display device has an array of pixels comprising light emitting display elements, for example EL elements, carried on a substrate and associated light sensing elements responsive to light emitted by the display elements. The light sensing elements each comprise a gated photosensitive thin film device such as a TFT structure or a lateral gated pin device having a semiconductor layer with contact regions laterally spaced on the substrate and separated by a gate controlled region. A part of the associated display element extends over the gate controlled region with an electrode of the display element serving as the gate of the photosensitive device thereby ensuring good optical coupling between the display element and the photosensitive device and enabling the gate to be appropriately biased. Such an arrangement enables, for example, the provision of electro-optic feedback control in the pixel in comparatively simple manner.