Fuji Xerox has demonstrated its latest electrophoretic color e-paper model on the opening day of this week's SID 2012, held in Boston. Interestingly, the new prototype doesn't use a color filter, as has been the case with previous models. Because of this, the e-paper design allows for brighter and more vivid color reproduction.

The e-paper prototype measures 5.0-inches, with 600x800 pixels, 200dpi, a graduation of four, reflectance rating of 30% and a contrast ratio of 10:1. The vivid and brighter color reproduction is a result of the moving of colored particles to change the color displayed. This is achieved by using magenta and cyan colored particles with different threshold values (electric field). 

A layer of white particles is sandwiched between the front and rear layers which removes the requirement to use a filter and enables the display to show a blank white image when required. This is achieved by drawing all the colored pixels behind the white layer when white needs to be drawn. Color is achieved in the opposite way, by moving the differently charged color particles in front of the white layer as required to produce the image.

The company is now working on a new full color prototype using three colors. It has developed cells (pixels) using magenta, cyan and yellow and research is currently underway to design a method to utilize all three colors in a single e-paper display. Fuji Xerox say the finished model will produce a wider color gamut than a newspaper.