19 Jul 2005
Flexible color electronic paper developed by Fujitsu could be used to display adverts as early as next year.
Japanese electronics giant Fujitsu has developed flexible color electronic paper that can display an image continuously without using electricity. The company says this "image memory function" makes its technology an ideal replacement for paper used in advertisements boards seen inside trains and buses.
Fujitsu is now testing its electronic paper and hopes to commercialise it during its fiscal year April 2006 to March 2007. The company however would not comment on what products will be commercialised.
As well as the image memory function, another key feature of the display is its flexibility. Fujitsu says that the display is unaffected even when it is bent or pressed with fingers. "The screen image can be changed with no distortion to the color at a bending radius of 60 mm," Scott Ikeda, Fujitsu's public relations manager, told Optics.org.
Based on a proprietary flexible film substrate, the electronic paper uses three displaying layers: red, green and blue. Fujitsu says that because no color filters or polarizing layers are required, the paper produces colors that are significantly more vivid than conventional reflective-type LCDs.
"The display is a passive-matrix, reflective-type cholesteric liquid crystal display," said Ikeda. "The 3.8-inch diagonal prototype has 105 pixels per inch and 320 x 240 pixels (QVGA). We believe that over 300 pixels per inch is technically possible."
The current three-layered prototype is approximately 0.8 mm thick and Fujitsu expects to reduce the thickness in the future.
Although targeting advertisements initially, Fujitsu lists other applications as electronic shelf pricing displays and short-term information displays such as operating manuals. It adds that when the screen image needs to update, the display consumes a minimal amount of electricity.
Fujitsu is not the only firm to be chasing the dream of electronic paper. Both Eink of the US and ZBD Displays of the UK have also developed their own "image memory" technology based on electrically-charged pigment particles and a bi-stable LCD respectively. However, neither firm can currently offer displays capable of supporting color images.