Semiconductor Energy Laboratory Co Ltd (SEL) exhibited 13.5-inch and 3.4-inch OLED panels at FPD International 2012, which took place from Oct 31 to Nov 2, 2012, in Yokohama, Japan.
SEL and Sharp Corp announced the technologies used to develop the panels at SID 2012, which took place in June 2012 in Boston, the US (See related article). This is the first time that the panels have been shown to the public in Japan.
The pixel counts of the 13.5-inch and 3.4-inch panels are 3,840 x 2,160 (4k2k) and 960 x 540, respectively. Both of the panels have a resolution of 326ppi and use oxide semiconductor TFTs having a structure called "CAAC (c-axis aligned crystal)," in which the crystal of an IGZO layer is grown in the c-axis direction, as driver elements.
To realize color display, white OLED devices were combined with red, green and blue color filters. The device structure is a top-emission type that extracts light from the side opposite to the TFT substrate. The 3.4-inch panel can be used for flexible displays because it uses a resin substrate.
The latest prototypes of the two panels have higher display properties than previous prototypes, SEL said. The driver elements and OLED devices were prototyped at Advanced Film Device Inc (AFD), which is a wholly owned subsidiary of SEL, and SEL, respectively.
The structure of the OLED device of the previous 3.4-inch prototype was a top-emission type that extracts light from a TFT substrate. The weight and thickness of the new 3.4-inch prototype are 2g and 0.1mm or less, respectively. Its flexibility was realized by forming driver elements, OLED devices, etc on a glass substrate and, then, replacing the glass substrate with a resin substrate.