Abstract: The present invention provides thioaluminate phosphor compounds BaAl2S4 and BaAl4S7 with novel crystal structures that have higher luminosity and improved color coordinates. The invention is also directed to rare earth element activated barium thioaluminate phosphor films comprising a phosphor compound having a novel crystal lattice structure that increases the electroluminescent light emission from the film. The phosphor films are for use in electroluminescent displays and in particular, thick film dielectric electroluminescent displays.

Abstract: The invention provides a method of forming a thick film dielectric layer in an EL laminate of the type including one or more phosphor layers sandwiched between a front and a rear electrode with the phosphor layer being separated from the rear electrode by a thick film dielectric layer. The method includes depositing a ceramic material in one or more layers by a thick film technique to form a dielectric layer having a thickness of 10 to 300 ?m; pressing the dielectric layer to form a densified layer with reduced porosity and surface roughness; and sintering the dielectric layer to form a pressed, sintered dielectric layer which, in an EL laminate, has an improved uniform luminosity over an unpressed, sintered dielectric layer of the same composition.

Abstract: The present invention is directed to color electroluminescent displays comprising a novel sub-pixel structure and method for making the same. The sub-pixel structure has an electroluminescent phosphor, which emits blue light, and a photoluminescent phosphor, which emits at least one other color as a result of absorption of the blue light. The invention is also directed to novel photoluminescent phosphor materials.

Abstract: The invention relates to a thick film dielectric electroluminescent display having a patterned layer. The patterned layer is patterned using a laser ablation method including selecting a wavelength of laser radiation, a laser pulse length, a laser energy density and a sufficient number of laser pulses to pattern the layer without substantial ablation of or damage to other layers, whereby the wavelength of laser radiation is such that the laser radiation is substantially absorbed by the layer with minimal absorption by other layers, the laser pulse length is sufficiently short that during the duration of the laser pulse there is minimal heat flow from the layer to other layers, and the laser energy density and the sufficient number of laser pulses is sufficiently high that energy is deposited in layer, whereby at least a portion of the layer is ablated and the luminance of an unablated area of the display is comparable to the luminance of an equivalent area of an unpatterned but otherwise identical display.

Abstract: The invention is a novel sputter target and deposition method for multi-element thin film phosphors for thick film dielectric electroluminescent displays in which the deposited phosphors provide a high luminance and colors required for TV applications. The method comprises sputtering a single composite target in a low pressure sputtering atmosphere that comprises gases containing reactive species and non-reactive species. The composite target comprising a matrix phase and an inclusion phase, or two matrix phases, wherein one of the phases comprises one or more metallic elements that contribute to the composition of the phosphor and the other of the phases comprises the remaining elements that contribute to the composition of the phosphor.

Abstract: The present invention is an electroluminescent display that incorporates a laminated seal that inhibits exposure of display components to atmospheric contaminants and to a sealing process for fabrication of the same. The sealed electroluminescent display comprises a substrate upon which is constructed a thick dielectric electroluminescent display covered by a laminated seal comprising a lower multi-functional polymer film and an upper inorganic film that provides a barrier layer to inhibit exposure of the electroluminescent display structure to an atmospheric contaminant.

Abstract: A driver apparatus for an electroluminescent display comprising a plurality of rows to be scanned and a plurality of columns which intersect the rows to form a plurality of pixels, comprises addressable row drivers, each row driver applying an output voltage to its associated row when addressed. The value of the output voltage is approximately equal to the numerical average of the threshold voltage for the electroluminescent display and the voltage required to provide the maximum desired pixel luminance for the electroluminescent display. Bipolar column drivers each supply an output voltage to its associated column. The output voltage is either positive or negative depending on the desired luminance of the pixels. The range of both positive and negative column output voltages is from zero volts to about one half of the difference between the threshold voltage and the voltage to provide the desired maximum pixel luminance for the electroluminescent display.

Abstract: A thin film phosphor for an electroluminescent device, the phosphor being selected from the group consisting of thiasluminates, thiogallates and thioindates having at least one cation selected from elements of Groups IIA and IIB of the Periodic Table of Elements. The phosphor being activated by a rare earth metal and containing a Group IIIB element as a partial substitute for a portion of aluminum, gallium or indium of the thiogallate, thioindate and thioaluminate. The phosphor provides improved luminance. An electroluminescent device consisting of the thin film phosphor on a substrate is also described.

Abstract: The invention provides a method of forming a patterned phosphor structure having red, green and blue sub-pixel elements for an AC electroluminescent display. The method involves selecting first and second phosphors, each emitting light in different ranges of the visible spectrum, but whose combined emission spectra contains red, green and blue light; depositing and patterning the phosphors in a layer to form a plurality of repeating phosphor deposits; and providing means associated with the phosphor deposits, and which together with the phosphor deposits form the red, green and blue sub-pixel phosphor elements, for setting and equalizing the threshold voltages, and for setting the relative luminosities of the red, green and blue sub-pixel phosphor elements so that they bear set ratios to one another at each modulation voltage used to generate the desired luminosities for red, green and blue; and optionally annealing the patterned phosphor structure so formed.