Eitaro Nishigaki

Multicolor organic electroluminescent QVGA display devices with patterned lateral three-color emitters

Multicolor organic electroluminescent QVGA display device shave been developed through application of patterned lateral three-color electroluminescent layers which are driven by the single matrix method. The devices have achieved almost practical level in their performance. The organic electroluminescent layers and the metal cathodes have been fabricated using metal shadow masks. Further examination of the panel fabrication process and the organic materials has been made, and the results have been applied to the display devices. The organic electroluminescence device structure of the display panel is a four-layer stack consisting of a hole injection layer, hole transport layer, light emitting layer, and electron transport layer. The display pixel consists of three color elements which are green, orange, and blue. The green and blue emitting materials and the electron transport material have been newly developed. The display panel has been encapsulated by a glass cap and driven by the single matrix method. At the Japan Electronics Show in October 1997, the early stage sample of this display device has been demonstrated at video rate moving pictures. After then several improvement have been achieved on the driving technology and on the panel fabrication technology and the display succeeded to perform at 80 cd/m2 of maximum luminance. In this paper,the fabrication and operating method of the electroluminescent panel are reported.