For its 75th anniversary edition, Esquire magazine took a bold technology flyer, embedding a pair of E Ink electrophorectic displays (EPD) in a limited edition of the its cover.
The October cover includes an electronic assembly that operates an outward-facing panel. The panel is visible when the magazine is closed. Finally, a second display is integrated with an advertisement on the cover's inside face.
Esquire's application of E Ink's display technology might best be called an animation rather than a truly addressable display. Static patterns are flashed (in the black or white state) to blink words and geometric patterns in the display panels, both of which are overlaid with semi-transparent color artwork to enhance visual appeal. Pictures are "lit up" on the front panel with underlying white-state squares, and the phrase, "The 21st Century Begins Now" animates through in white-on-black display.
|Esquire's October 2008 electronic cover|
The image sequence shown provides a static idea of the display states, but various YouTube videos show the cover in action. The inside cover panel is used as a backdrop animation for a car ad, with display images manipulated to achieve a sense of motion behind the car and in its wheels.
Also, called E-Paper, E Ink's technology relies on the use of an electric field to bring forward to viewers tiny absorptive (black) or reflective (white) particles suspended in microspheres. The two particle "colors" have opposite charges, meaning the application of a positive or negative field across the microsphere(s) brings the opposite-charged black and white particles to the viewing plane, respectively.
The technology is completely passive, using only reflected light. Nevertheless, the end result is a high-contrast, surprisingly visible black-and-white image.
E Ink's Web site has some visuals on how it all works, and various e-book readers from Sony, Amazon and others have used more complex forms of E Ink's panels to create an electronic substitute for paper in text applications. EPD technology is bistable, meaning once power is pulled from the panel, the last state of the display is maintained indefinitely.
Opening the front cover card stock, readers find all the electronics neatly taped in place. EPD panels align to the transparent graphics cutouts and a single circuit board which serves both panels lies in between.
The board is dominated by the six CR2016 3-volt Lithium coin-cell batteries which power everything. It appears that five of the six cells are strung together in a series to create a 15-volt rail used as the power supply for EPD panel drivers. While extremely low-power consumption is a hallmark of EPD, the boosted rail voltage is needed to generate sufficient electric fields for affecting particle movement in the E Ink microspheres.