US Patent 7843134 Organic EL emission devices connected in series

An organic electroluminescent apparatus including: a first emitting device having a first organic emitting layer between a first under electrode and a first upper electrode, and a second emitting device wherein a second organic emitting layer between a second under electrode and a second upper electrode. The second under electrode is electrically connected to the first upper electrode or is made of the same material as the first upper electrode. The two devices are placed on a common surface, yet the two devices exhibit different emission colors.