EL device having improved power distribution
An active-matrix electroluminescent device, comprising: a plurality of light-emitting elements laid out over a substrate, a plurality of electrical buses carrying a common signal connected to the light-emitting elements; and a plurality of electrical cross-connections intersecting and electrically connecting the plurality of electrical buses. The plurality of light-emitting elements are arranged in groups of four light-emitting elements each, each group forming a quad cell of four neighboring light-emitting elements arranged around intersections of the electrical buses and cross-connections, each of the light-emitting elements of each quad cell are connected to the electrical bus or electrical cross-connection separating the light-emitting elements of the quad cell, each quad cell shares a common electrical bus or cross-connection with an adjacent quad cell, and adjacent quad cells sharing a common electrical bus are not separated by a common cross-connection and neighboring quad cells sharing a common cross-connection are not separated by a common electrical bus.
1. An active-matrix electroluminescent device, comprising:
a plurality of light-emitting elements laid out over a substrate, each light-emitting element including a first electrode and a second electrode having one or more electroluminescent layers formed there-between, at least one electroluminescent layer being light-emitting, at least one of the electrodes being transparent and the first and second electrodes defining one or more light-emissive areas, and electronic components formed on the substrate connected to the first and/or second electrodes for driving the one or more electroluminescent layers to emit light;
a plurality of electrical buses carrying a common signal connected to the light-emitting elements;
a plurality of electrical cross-connections intersecting and electrically connecting the plurality of electrical buses;
wherein the plurality of light-emitting elements are arranged in groups of four light-emitting elements each, each group forming a quad cell of four neighboring light-emitting elements arranged around intersections of the electrical buses and cross-connections, two light-emitting elements of each quad cell being formed on each side of an electrical bus and two light-emitting elements of each quad cell being formed on each side of an electrical cross-connection;
wherein each of the light-emitting elements of each quad cell are connected to the electrical bus or electrical cross-connection separating the light-emitting elements of the quad cell, each quad cell shares a common electrical bus or cross-connection with an adjacent quad cell, and wherein adjacent quad cells sharing a common electrical bus are not separated by a common cross-connection and neighboring quad cells sharing a common cross-connection are not separated by a common electrical bus; and
wherein each quad cell comprises a single pixel having four light-emitting elements, a first light-emitting element emitting red light, a second light-emitting element emitting green light, a third light-emitting element emitting blue light, and a fourth light-emitting element emitting white, cyan, yellow, or magenta light.
2. The active matrix device of claim 1 , wherein the light-emitting elements of a quad cell on one side of an electrical bus or cross-connection have a reflected layout of the light-emitting elements of the quad cell on the other side of the electrical bus or cross connection.
3. The active matrix device of claim 1 , wherein the light-emitting elements of a quail cell on one side of an electrical bus have a reflected layout of the light-emitting elements of the quad cell on the other side of the electrical bus and the light emitting elements on one side of the electrical cross-connection of the same quad cell have a reflected layout of the light-emitting elements of the quad cell on the other side of the electrical cross-connection.
4. The active matrix device of claim 3 , wherein each of the light-emitting elements of a quad cell are connected to the electrical bus or the electrical cross-connection of the same quad cell closer to the intersection of the electrical bus and the electrical cross-connection than to edges of the quad cell.
5. The active-matrix electroluminescent device of claim 1 , wherein the electrical cross-connections are formed orthogonal to the electric buses.
6. The active-matrix electroluminescent display device of claim 1 , wherein the electrical buses carry a power or a ground signal.
7. The active-matrix electroluminescent device of claim 1 , wherein the electrical buses and cross-connections are formed in a common step and in a common layer.
8. The active-matrix electroluminescent device of claim 1 , wherein the electrical buses and cross-connections are formed in separate steps and in separate layers and are electrically connected through connection vias at each intersection.
9. The active-matrix electroluminescent device of claim 1 , further comprising a controller for driving the light-emitting elements of the pixel in combination so that the individual peak design currents for each light-emitting element are not employed simultaneously for all four light-emitting elements of the same pixel.
10. The active-matrix electroluminescent device of claim 1 , further comprising a controller for driving the light-emitting elements of the pixel in combination to limit the current provided to each quad-cell such that the light intensity of at least one of the light-emitting elements, when all four light-emitting elements are employed simultaneously, is lower than the light intensity of the same light-emitting element when the color of light that is being displayed is approximately equal to the color of the light-emitting element.
11. The active-matrix electroluminescent device of claim 1 , wherein the quad cell groups of light-emitting elements are rectangular in shape.
12. The active-matrix electroluminescent device of claim 1 , wherein the light-emitting elements comprise OLEDs.