Exploring a New Generation of Signage and Graphics Materials
The displays E Ink sells to Sony support four levels of grayscale and resolution of about 190 points/in. The high-res displays use thin-film transistors (TFTs), which essentially are current-carrying devices fabricated of thin films of silicon deposited on glass. Sony used the high-res displays in an e-book reader it developed in 2004, called LIBRIé. The Sony Reader, a model developed for the American market, may be available this year.
E Ink's future focus includes color displays (Figure 3). Haight says the company hopes to sell color units either at the end of 2007 or early in 2008. The company currently overlays a color filter array on its E Ink Imaging Film—the same way LCD displays use color—but Haight says E Ink's researchers may be working on ways to use color inks. Flexible displays are also on the agenda.
"Because [our displays] are made on a plastic film, they're inherently flexible," Haight explains. "The problem has been that the electronics that marry with them are not flexible. Currently, there is no thin-film transistor in mass production that is flexible, which has really been a stumbling block to have an e-book reader that you could roll up or fold. If you wanted high resolution, that's not possible. TFTs currently are made mostly on glass."
Even though graphics and industrial printers aren't able to print E Ink's microcapsules or buy its finished films, opportunities exist to print on accessory items and components used in products that employ E Ink's technology. E Ink also sells a prototype kit that gives product designers access to the technology. The kit may be useful to shops that are exploring high-tech OEM projects to pair with their printing capabilities. The kit includes an active-matrix display made of E Ink's imaging film and the hardware and software necessary to produce a fully functional portable device.
Another take on electronic paper
"The simplest analogy: We can do television on paper," says Michael Feldman, president of Quantum Paper, Bloomfield Hills, MI. The company has developed two types of electronic paper: a static display (Figure 4) and an addressable, dynamic display. Both are flexible and rollable—but not foldable, and Feldman notes that their current draw is similar to static electricity. Neither display is bistable.
Did you enjoy this article? Click here to subscribe to the magazine.