Abstract: An organic light-emitting diode (OLED) device, comprises: a first electrode and a second transparent electrode having one or more organic layers formed there-between, at least one organic layer being light-emitting; and a contrast enhancement element formed on a side of the second transparent electrode opposite the organic layers, wherein the contrast enhancement element comprises a patterned reflective layer for reflecting emitted light and a corresponding light-absorbing layer for absorbing ambient light, wherein the reflective layer is located between the light-absorbing layer and the second transparent electrode and wherein the corresponding layers form one or more transparent openings through the reflective and light-absorbing layers so that light emitted by the light-emitting organic layer passes through the transparent openings.

Abstract: A time sharing method and apparatus for frequency reuse in cellular communication systems. Frequency reuse is enhanced by synchronizing cell transmit/receive base stations in a cellular system to a common time base, and then sharing the available frequencies via allocated time slots. Cells using the same frequency that may interfere with each other are activated only during selected time intervals while same-frequency cells nearby are deactivated. The deactivated cells are then in turn activated while previously activated same-frequency cells nearby are deactivated. The frequency time slots may be of equal length, or longer time slots may be allocated to cells having higher usage rates, as determined in any of a number of ways. The time slots may be mutually exclusive, or may overlap. The time sharing technique of the present invention allows design of cell systems with many reuse patterns.