Abstract: A multilayer structure for use in a photosensor. The multilayer structure includes a substrate, a thin film transistor comprising a metal oxide semiconductor channel and a photosensing element comprising amorphous silicon. The thin film transistor is electrically connected to the photosensing element, and the thin film transistor and photosensing element are on the substrate and separated by a hydrogen barrier structure.

Abstract: An imaging system that removes an electrical charge from a sensor. The system includes a generator that generates x-rays, a sensor that stores an electrical charge, a plate positioned above the sensor and a light source. A controller determines whether the electrical charge should be removed from the sensor. If it is determined that the electrical charge should be removed, the controller controls the light source to illuminate the plate to distribute the light on a top surface of the sensor. A method includes arranging a plate above the sensor and a light source next to the plate, generating x-rays towards the sensor, and storing an electrical charge in the sensor. If it is determined that the electrical charge should be removed, the light source is controlled to illuminate the plate so that the light from the light source is distributed on a top surface of the sensor.

Abstract: A clamping circuit including a clamping diode, a bias line, and a clamp line is incorporated into a pixel circuit of amorphous silicon sensor arrays. The clamp diode in each pixel prevents the voltage across the photodiode from dropping below a specific threshold. By keeping the photodiode under reverse bias even under conditions that may otherwise saturate the pixel, image lag is reduced. In full fill factor amorphous silicon sensor arrays, a clamping circuit includes a clamp TFT, a bias plane, a clamp line, and a drain line. The clamp TFT reduces lag and blooming by draining off excess current developed under overexposure conditions. A method to globally reset a sensor array and a method to test and repair a TFT matrix in full fill factor sensor arrays without damaging the overlying collection electrode and sensor layer are also provided.

Abstract: An x-ray imager and method of fabricating an x-ray imager that provides protection to the sensor arrays and the barrier layer from the corrosive effects of the scintillating material. The x-ray imager includes a benzo-cyclo-butene layer between the barrier layer and the scintillating material. The benzo-cyclo-butene layer provides several advantages including low cost and application by spin coating or spray coating.

Abstract: An array is fabricated in which a cell's dark matrix overlaps its cell electrode so that the overlap areas and the dielectric material between them form a storage capacitor. Each cell's dark matrix can overlap the cell's electrode around its perimeter, and the overlap areas of the dark matrix and the electrode can be sufficiently large and the dielectric layer between them can be sufficiently thin that the storage capacitor they form meets the cell's requirements. The dark matrix can be over the cell electrode, with scan lines and data lines in a series of lower layers, or the dark matrix can be below the series of layers that includes scan lines and data lines, with the cell electrode in an opening defined in the series of layers. The dark matrix layer can be electrically connected to a fixed potential.

Abstract: A sensor array has cells, each with a sensing element and a switching element. The sensing element includes a charge collection electrode. An anticoupling layer between the charge collection electrodes and the data lines is structured to reduce capacitive coupling between the electrodes and the data lines below a threshold level at which crosstalk is unacceptable. If charge collection electrodes overlap data lines, the anticoupling layer can reduce capacitive coupling so that crosstalk is no greater than 2%. The anticoupling layer can be a dielectric layer with dielectric constant less than 6 and with thickness greater than 1.5 .mu.m, with the dielectric constant being sufficiently low and the thickness sufficiently great that the anticoupling layer reduces capacitive coupling below the threshold level.

Abstract: A system includes a sensor array with scan lines, data lines, and, for each cell, a sensing element and a switching element. Each sensing element includes a charge collection electrode. The sensing elements are stimulated during an interval in which data lines are electrically connected to a fixed potential, reducing induced charge and crosstalk. The stimulation could, for example, be x-ray radiation. Then, during a following interval, a scan signal has a duty interval after which signals are read out from the data lines. During stimulation, the data lines can be connected to ground or can be connected to virtual ground by resetting their sense amplifiers.

Abstract: A process of producing a product such as an x-ray sensor array performs two etching operations on an insulating layer to expose different parts of a conductive layer. One etch exposes part of the conductive layer in each unit of cell circuitry in the array without exposing the contact pads at the array's periphery. Then, a conductive layer including ITO is deposited over the insulating layer and patterned to form a conductive element for each unit, with the conductive element contacting the exposed part of the conductive layer. Afterward, a second etch exposes contact pads at the periphery of the array. As a result, the contact pads have high quality surfaces, facilitating testing and wire bonding.

Abstract: A product such as an x-ray sensor array includes, for each unit of cell circuitry, a capacitor with upper and lower electrodes. A conductive layer that includes highly conductive metal such as aluminum is patterned to include the upper electrode of the capacitor, the contact leads of a switching element, and the data lines of the array. The upper electrode has an exposed area due to an opening in an insulating layer over it. A conductive element, such as an ITO island, is formed over the insulating layer, contacting the exposed area of the upper electrode so that the conductive element is electrically connected to one of the contact leads of the switching element through the upper electrode. The conductive elements of adjacent units can be separated by the minimum spacing necessary to ensure isolation. Or each unit's conductive element can be offset slightly from the data and scan lines and can also be pulled back from the channel of the switching element, which can be a TFT.

Abstract: An image sensor array has overlapping responsive zones for detecting incident radiation. The sensor array includes a plurality of collection electrodes for sensing charge and a charge distribution layer in contact with the collection electrodes. The charge distribution layer is configured to distribute charge generated from incident radiation to more than one collection electrode, effectively providing overlapping responsive zones that reduce adverse aliasing effects.

Abstract: A photodetecting device and a method for constructing the photodetecting device. The photodetecting device provides at least one transistor formed over a substrate and at least one photodiode formed over the at least one transistor. Each of the at least one photodiode is coupled to one of the at least one transistor. The fill factor of the photodiode is very high even when the resolution of the photodetecting device is increased. The photodetecting devices are formed in a matrix having rows and columns. The matrix of photodetecting devices forms a two dimensional imaging device.

Abstract: Sensor elements which are capable of sensing illumination edges with subpixel accuracy are described. The sensor elements include a plurality of conductive storage nodes and a plurality of collection electrodes which are in a low resistance, touching relationship with a first semiconductive material layer. A second semiconductive material layer is placed over the first such that the first and second semiconductive material layers and the storage nodes form light sensors. Near the first semiconductive layer is a gate electrode. When a first voltage is applied to the gate electrode the resistance of the first semiconductive material layer between the storage nodes and the conductive collection electrodes is high. Illumination which strikes the sensor element creates electron hole pairs which induce charges on the storage nodes.

Abstract: Pixel elements capable of imaging spatial intensity variations within themselves, and displays comprised of such elements, are described. The pixel elements include a resistance layer disposed between at least one set of electrodes. Over that resistance layer is a liquid crystal material. Over that liquid crystal material is a field electrode. In operation a voltage, whose components are referenced to the field electrode, is applied across the resistance layer. The resulting current flow induces a spatially varying electric field between the field electrode and the resistance layer. That spatially varying electric field results in a corresponding response by the liquid crystal layer which results in a spatially varying light transmission through the liquid crystal material. By varying the voltage across the resistance layer and/or the voltage applied to the field electrode varying amounts of light transmission can be achieved.

Abstract: Resistance layer structures comprised of a plurality of conductive charge storage nodes, collection electrodes, and an electrically controllable resistance element which connects the storage nodes and the collection electrodes. The resistance of the electrically controllable resistance element can be switched between a low impedance, so as to permit a rapid charge interchange between the various storage nodes and the collection electrodes, and a high impedance, so as to permit an integration of charge onto the storage nodes. Beneficially, the electrically controllable resistance element is implemented as the active region of a metal-insulator-semiconductor device.

Abstract: A polysilicon multiplexer for two-dimensional image sensor arrays is provided. Multiplexing the gate and data lines of a two-dimensional image sensor array greatly simplifies the packaging required for large devices with high resolution. The multiplex transistors are polysilicon for required read out speed. The multiplexer structure of polysilicon TFTs and sensor arrays of amorphous silicon TFTs are formed on a single substrate wherein the polysilicon TFTs are formed by laser crystallization on an outer periphery of the substrate.

Abstract: Techniques for improving droplet uniformity in acoustic ink printing. Row to row variations in an average droplet characteristic are reduced by controlling the electric power applied to the droplet ejectors of the individual rows. By applying the proper power to each row, the average droplet characteristic from the individual rows are made substantially. Another technique varies the efficiency of the individual droplet ejectors by physically trimming (such as with a laser) one or more of its components. Trimming may be performed on a droplet ejector's transducer, varactor, one or more associated resistors, or one or more capacitors. Yet another technique controls droplet ejector efficiency by electrically controlling the capacitance of a varactor associated with each droplet ejector, and thus each droplet ejector's efficiency.

Abstract: A color scan array for linear imaging employing a matrix of photo-sensor and thin-film transistor (TFT) elements aligned in parallel rows with each row representing the same color and sub-pixels of a linear array of pixels. The rows of sub-pixels are sub-divided into groups, with the TFT of each color group commonly connected to a data line, and with plural gate lines provided each connected to the corresponding TFTs of the sub-pixels of each group pixel. The result is a short, compact sensor with a relatively small number of crossings and thus reduced capacitance and increased responsivity.

Abstract: A marking array for use in an ionographic marking apparatus in which the ion modulation structure is subject to a lighly corrosive atmosphere. Improved marking electrodes are provided which comprise a thin film body of a conductive material having a surface which is chemically neutral to the corona effluents.

Abstract: An ionographic marking apparatus capable of multifunction operation for use as an input printer, a document copier or a document scanner. The apparatus includes a writing head comprising thin film elements including ion modulating electrodes, data and address lines, and self-biasing amplification circuits including thin film transistors, resistors and photosensors integrally fabricated upon a large area substrate.