02 Jun 2005
Double-sided OLEDs target miniature displays in mobile phones and digital cameras.
Mobile phones could soon be getting a new look if a double-sided organic display developed by AU Optronics of Taiwan proves popular. The new active-matrix organic display (AMOLED) generates 1.5 inch-sized full-color images on both its front and rear surfaces and is controlled by a single IC driver chip.
It was unveiled in a paper at the SID conference which took place in Boston, US, last week. According to the paper, the new device can replace LCD double-display modules (made from two LCDs assembled back-to-back) that are found in mobile phones and digital still cameras (DSCs).
In the new AMOLED structure, the sub-pixel area is divided into two regions designed for top-emission and bottom-emission. A transparent layer of indium tin oxide (ITO) is used as the anode in the bottom-emitting sub-pixels, while a reflective Ti/Al/Ti/ITO sandwich-type structure is used as the anode for top-emitting sub-pixels. Each side of the display has a resolution of 128x120 pixels, 16-bit color and a brightness of up to 150 nits and is capable of showing independent images.
According to J.J.Lih, director of OLED operations at AUO, the company is set to commence mass production of its full-color AMOLED displays later this year. “We expect our AMOLED displays to have a lifetime of over 10,000 hours, which is good enough for applications like mobile phones and DSCs,” he said. However, the company declined to divulge details of specifications and volumes of the displays that it plans to manufacture.
The news comes shortly after AUO’s April announcement that it will invest about $1.12 billion for a “Generation 7.5” TFT-LCD fabrication facility that will use 1,950 x 2,250 mm glass substrates with a monthly input capacity of 30,000 substrates. This fab, which will be the company’s ninth, will enable AUO to target the HDTV market segment, with the option to produce 42-inch, 47-inch or 56-inch panels. Construction of the new fab building has already been completed, and commercial production is expected to commence in Q4 next year.
Manoj Aravindakshan is director of On Target Media, a Singapore-based provider of technology news.