Tokyo May 18 — Ricoh Company, Ltd. (President & CEO: Shiro Kondo) announced that the company, utilizing its original display method, has achieved a display of color still images with about 2.5 times brighter (in white reflectivity) and about 4 times wider color reproduction range compared with presently commercialized or announced color electronic paper technologies.
Electronic paper, having no luminous source, differs from a conventional display unit-it requires no electric power except for rewriting characters and images. Known as a technology gentle on the environment and the human eye, 6.6 million monochrome devices for reading digital books are now sold annually throughout the world and sales are predicted to exceed 11 million readers in 2011 (*1). Although color devices have long been desired, the methods proposed for color electronic paper have thus far not been able to solve the lack of brightness or color reproducibility, even in theory. Therefore the color electronic paper market is expected to grow significantly with future technology development, greatly expanding possible applications.
(*1) Gartner Report: "Competitive Landscape: Connected E-Readers, North America," published on December 8, 2010.
Ricoh developed the world's first new organic electrochromic material (*2) producing three primary colors (Cyan, Magenta and Yellow) while improving memory properties in March 2009. The company at the same time proposed a simple laminating element structure, forming three electrochromic layers between two substrates. This was made possible by stepping outside the box and beyond the original display methodology hitherto in vogue. This proved the feasibility of color electronic paper capable of achieving a bright display at low power consumption and low cost.
(*2) Joint development with Yamada Chemical Co., Ltd. (Kyoto, President: Shimpei Yamada).
Based on this result, Ricoh moved from the development phase of element technology to the development of a practical application of prototypes featuring high resolution electronic paper. This led to success in achieving bright images with high color image reproducibility. Ricoh will accelerate development toward practical application by improving reliability/repetition durability (guaranteeing tens of thousands of rewrites) and larger screen size. Although development will expand to include document display devices that can display fine characters, the evolution will progress with various applications developing in parallel.
An example of color image display by lamination electrochromic method
Ricoh introduced this technology at DISPLAY WEEK 2011 of SID (The Society for Information Display) held in Los Angeles from May 15 to 20.