There is provided a circuit for driving an organic light emitting diode (OLED). The circuit includes a current source for providing current to a first terminal of the OLED, and a generator for providing a variable voltage signal to a second terminal of the OLED to facilitate control of the current....http://www.google.de/patents/US7071932?utm_source=gb-gplus-sharePatent US7071932 - Data voltage current drive amoled pixel circuit
