William here, talking about the sweeping changes taking place in the world of electronic displays.
Tomorrow's displays are here today and big changes are coming sooner than you think. Displays are being built into huge sections of walls, hand-held reading devices the size of books, and tiny devices no bigger than quarters, and it's all being done in significantly different and less costly ways than you'd ever image. Two driving technologies are behind these changes: e-ink and e-paper.
E-ink technology is what makes reading on a Sony Reader or Amazon Kindle similar to reading text on paper. The reader's high-contrast, high-resolution display makes it readable in direct sunlight and at angles up to 180 degrees. When you turn pages in an electronic book (e-book), the reader uses power to turn on the e-ink pixels. Once a page is displayed, the reader doesn't use power to maintain the page. This helps ensure the battery lasts longer than a standard Portable Digital Assistant (PDA).
E-ink contains millions of tiny microcapsules, about the diameter of a human hair. In one version of the technology, each microcapsule contains positively charged white particles and negatively charged black particles suspended in a clear fluid. When a positive electric field is applied, the black particles move to the top of the microcapsule where they become visible to the user and this is what makes the surface appear black at that spot. Simultaneously, an opposite electric field pulls the white particles to the bottom of the microcapsules where they are hidden from view. By reversing this process, the white particles appear at the top of the capsule, which makes the surface appear white at that spot.
To create an Electronic Paper Display (EPD) for an electronic device, the e-ink is printed onto a sheet of plastic film. By laminating this film to a layer of circuitry, the circuitry forms a pattern of pixels that can then be controlled by a display driver. The screen printing process can be used to create an EPD on virtually any surface, including glass, plastic, fabric and even paper.
Just imagine the possibilities. Next up, I'll dig in and talk more about the processes used to create EPDs.
William R. Stanek
williamstanek at aol dot com