Technology of Electronic Ink
E Ink is the inventor of several types of electrophoretic ink, often called electronic ink. When laminated to a plastic film, and then adhered to electronics, it creates an Electronic Paper Display (EPD). Although futuristic-sounding, electronic ink is actually a straightforward fusion of chemistry, physics and electronics. It’s so much like paper, it utilizes the same pigments used in the printing industry today.
Principle of two-color electronic ink
E Ink’s two pigment electronic ink system is made up of millions of tiny microcapsules, each about the diameter of a human hair. Each microcapsule contains negatively charged white particles and positively charged black particles suspended in a clear fluid. When a positive or negative electric field is applied, corresponding particles move to the top of the microcapsule where they become visible to the viewer. This makes the surface appear white or black at that spot.
Two-color electronic ink animation
Principle of 3-color electronic ink
E Ink’s Spectra product line utilizes a 3-pigment ink system in a microcup structure. This ink was engineered specifically for Electronic Shelf Labels (ESL) and is offered in black, white and red, and black, white and red. This ink system works similarly to the dual pigment system, in that a charge is applied to the pigments, and to a top and bottom electrode to facilitate movement. However, instead of the use of microcapsules, this system utilizes Microcups®, which are filled with the liquid and sealed.
E Ink also offers a 3-pigment ink system with monochrome plus yellow), which has been increasingly applied to retail stores as electronic shelf labels (ESL) in recent years.
Advanced Color ePaper(ACeP)
In 2016 E Ink showcased a multi-pigment ink system, Advanced Color ePaper (E Ink ACeP™). ACeP™ achieves a full color gamut, including all eight primary colors, using only colored pigments. The ink can be incorporated into either microcapsule or microcup structures. Color is achieved by having all the colored pigments in every pixel, removing the need for a color filter array. ACeP™ maintains the ultra-low-power and paper-like readability under all lighting conditions of regular E Ink ePaper.