Toppan Printing Co Ltd and Plastic Logic Ltd exhibited a prototype of flexible electronic paper (e-paper) whose size is equivalent to a 42-inch display as large-size digital signage at Retailtech Japan, which took place from March 5 to 8, 2013, in Tokyo.
The e-paper was made by using 16 pieces of 10.7-inch black-and-white e-paper whose pixel count is 1,280 x 960.
For the display device of the e-paper, E Ink Holdings Inc's electrophoretic front plane laminate was employed. And the front plane laminate was driven by an organic TFT substrate manufactured at Plastic Logic's Dresden Plant in Germany.
Plastic Logic has been developing flexible organic TFT substrates since 2007. It started to construct a manufacturing plant for the substrates in 2008. In 2011, it established a volume production system and since then has been producing organic TFT-driven displays by using the 3.5th generation-size plastic substrate.
The biggest challenge for the volume production of organic TFT-driven displays was the transfer of technologies from the research and development (R&D) facilities to the manufacturing plant, said Dean Baker, general manager, Commercial Development Asia, Plastic Logic.
At the R&D facilities, only one piece of 10.7-inch e-paper was obtained per substrate. But, in the manufacturing plant, where the 3.5th generation-size plastic substrate is used, nice pieces of 10.7-inch e-paper are obtained per substrate. This process change required the most effort, he said.
By overcoming those challenges, Plastic Logic realized a production capacity of up to one million pieces per year. Baker expects that the e-paper will be used for subscreens of smartphones and tablet computers in addition to industrial use including digital signage.
Toppan Printing and Plastic Logic plan to continue to make improvements to the latest prototype in the aim of reducing the influence of the seams of e-paper pieces on visibility. They intend to use two method to achieve this goal.
First, the companies consider increasing the size of e-paper from 10.7 inches to reduce the number of e-paper pieces from 16 to eight and from eight to four. Second, they aim to eliminate the bumps of the seams by connecting e-paper pieces in a way that they become flat.