Abstract: A method for the deposition of a thin film of a pre-determined composition e.g. a phosphor, onto a substrate, in which the composition is a ternary, quaternary or higher composition, especially a composition selected from the group consisting of thioaluminates, thiogallates and thioindates of at least one element from Groups IIA and IIB of the Periodic Table. In the embodiment, the method comprises placing a pellet of at least one sulfide on a first source and placing a pellet of at least one sulfide on a second source, with one pellet containing dopant. Vapor deposition onto the substrate is effected with separate electron beams. The rate of vaporizing of the sulfides is monitored with separate shielded coating rate monitors. The temperature of the sources is controlled to obtain the composition on the substrate. The method is particularly used for deposition of ternary or quaternary phosphors on substantially opaque substrates in electroluminescent devices.

Abstract: The performance and stability of thick film electroluminescent displays is enhanced by a non-porous layer inserted between the thick film dielectric layer and thin film phosphor structures in these displays. The inserted layer facilitates increased luminance, increased energy efficiency and improved operating stability.

Abstract: A circuit and method are provided of driving a display panel requiring gray scale control wherein the voltage applied to a row of pixels is equal to the sum of voltages of opposite sign with respect to ground applied respectively to the row electrode and column electrodes whose intersection with the row defines the pixels. The pixels have a capacitance that may be voltage dependent such that energy is stored in the pixels when a voltage is applied across them. The driving circuit incorporates a resonant circuit that is able to efficiently recover capacitive energy stored on the row of pixels and transfer it to another row of pixels as the rows are addressed by the sequential application of a voltage on each row.

Abstract: A method of deposition of a phosphor in a single-source sputtering process, in which the phosphor is selected from the group consisting of ternary, quaternary or higher thioaluminate, thiogallate and thioindate phosphors, and composites thereof, synthesized with cations selected from Groups IIA and IIB of the Periodic Table of Elements. The phosphor is of a pre-determined composition of elements. The method comprising sputtering in a hydrogen sulphide atmosphere from a single source composition so as to deposit a composition on a substrate. The composition of the targets of the single source has a relative increase in concentration of elements of the phosphor that have a lower atomic weight compared to other elements in said phosphor. The relative increase is controlled such that deposition of the pre-determined composition is effected on the substrate. Preferred phosphors are barium thioaluminate (BaAl2S4:Eu), and barium magnesium thioaluminates.

Abstract: An electroluminescent display and driving method is provided wherein the rows of pixels are divided into sub-pixel sets and several different sets of sub-pixels are then addressed from within a larger superset of adjacent sub-pixels. The image data for the addressed sub-pixels is averaged with that for adjacent sub-pixels and is applied to the reduced number of larger sub-pixels in sequence. Consequently, for a given sequence of input frame data sets the time average over one frame for a portion of the sub-pixels at any location of the panel is substantially the same as that for a conventionally addressed sub-pixel in a prior art panel.

Abstract: A method of deposition of a phosphor in a single-source sputtering process, in which the phosphor is selected from the group consisting of ternary, quaternary or higher thioaluminate, thiogallate and thioindate phosphors, and composites thereof, synthesized with cations selected from Groups IIA and IIB of the Periodic Table of Elements. The phosphor is of a pre-determined composition of elements. The method comprising sputtering in a hydrogen sulphide atmosphere from a single source composition so as to deposit a composition on a substrate. The composition of the targets of the single source has a relative increase in concentration of elements of the phosphor that have a lower atomic weight compared to other elements in said phosphor. The relative increase is controlled such that deposition of the predetermined composition is effected on the substrate. Preferred phosphors are barium thioaluminate (BaAl2S4:Eu), and barium magnesium thioaluminates.

Abstract: A driving circuit for powering an electroluminescent display using energy recovered from a varying panel capacitance of the display. The driving circuit comprises a source of electrical energy; and a resonant circuit using the panel capacitance for receiving the electrical energy and in response generating a sinusoidal voltage to power the display at a resonance frequency which is substantially synchronized to a scanning frequency of the display. The resonant circuit uses a step down transformer to reduce the effective panel capacitance of the display in order to reduce its effect on the resonance frequency.

Abstract: Improved circuitry for active matrix image arrays which, in one application reduces the number of source or gate lines for a given number of pixels, and in another application extends the dynamic range of the imaging array without reducing the number of source or gate lines. Each circuit includes multiple electrodes per pixel and multiple thin film transistors for switching charge from the pixel electrodes to the data line.

Abstract: A high resolution flat panel for radiation imaging includes an array of pixels arranged in rows and columns. Gate lines interconnect the pixels of the rows while source lines interconnect the pixels of the columns. Gate driver circuits provide gate pulses to the gate lines in succession in response to input from a control circuit to select the pixels on a row-by-row basis. The source lines lead to charge amplifiers for sensing the signal charges stored by the pixels when the pixels are selected. At least one pair of adjacent pixels in each row of the array shares a source line. Gating of the pairs of pixels in the rows that share a source line is controlled by control logic to ensure that signal charges stored by only one of those pixels is applied to a shared source line at a time. This allows the number of charge amplifiers in the flat panel to be reduced while maintaining high resolution.

Abstract: A flat panel detector for radiation imaging includes an array of pixels arranged in rows and columns. Gate lines interconnect the pixels of each row while source lines interconnect the pixels of each column. A radiation transducer is disposed over the pixel array. Each pixel includes a TFT switch having its gate electrode connected to a gate line and its source electrode connected to a terminal that is connectable to ground. The drain electrode of each TFT switch is connected to the pixel electrode of the pixel. The pixel electrode and a bottom electrode connected to a source line constitute a storage capacitor. When the TFT switch is biased and the pixel electrode is positively charged, the pixel electrode discharges through the TFT switch and onto the grounded terminal. This results in the release of negative charge held by the bottom electrode onto the source line, which is sensed by a charge amplifier connected to the source line.

Abstract: A flat panel detector for radiation imaging includes an array of transistor switches each of which is associated with a pixel electrode. A radiation transducer including a top electrode and a radiation conversion layer is disposed over the array. Inhibiting mechanisms are positioned over dead zones between adjacent pixel electrodes to inhibit the accumulation of charge in the radiation conversion layer at the dead zones when the top electrode is biased and the flat panel detector is exposed to radiation. In one embodiment, the inhibiting mechanism is constituted by islands formed of semiconductor material between the array and the radiation transducer. Each island is positioned over a dead zone between adjacent pixel electrodes and contacts a pixel electrode to allow charges accumulated on the islands to drift to the pixel electrodes.