Hardware Autopsy
spool. Each three-foot-wide roll of fi nished
product can contain up to two miles of mate-
rial that looks remarkably like paper.
A manufacturer like Sony creates an
active-matrix display by laminating E Ink’s
product to a thin-fi lm-transistor (TFT) back-
plane. A protective layer of either glass or
plastic is laid on top (plastic is thinner, light-
er, and cheaper). These displays typically
offer resolution of 170 dots per inch, but they
have the potential to deliver up to 375 dpi.
Smaller screens, such as the one Motorola
created for the Motofone, utilize a direct-
drive display. In place of a matrix of pixels,
direct-drive displays create images using a
limited number of addressable points—simi-
lar to an old-school digital watch display.BLACK AND WHITE AND GREEN
Electrophoretic displays are incredibly energy
effi cient, whether they’re deployed in an
active-matrix or direct-drive confi guration.
Once the pigment particles are arranged a
particular way to create an image, the display
is inherently stable and draws absolutely no
additional power until its particles need to
be rearranged to create a new image. LCD
and OLED displays, by contrast, must be
constantly powered to maintain an image.
And since the particles in an electrophoretic
display are made from the same type of
pigments used to produce paper and ink,
electronic paper is nearly as refl ective as con-
ventional paper: It doesn’t require an energy-
consuming backlight, it’s perfectly legible in
bright sunlight, it exhibits great off-axis visibil-
ity, and it causes much less eyestrain.ROLLIN’ ROLLIN’ ROLLIN’
Each of today’s commercial products based
on E Ink’s technology features a rigid display,
but fl exible and roll-up displays are not far
off. In fact, a company known as Polymer
Vision (a spin-off from European electronics
giant Philips) has been demonstrating a roll-
up prototype for more than a year. Devices
with roll-up displays could appear at retail in
less than two years.
Color displays using this technology
aren’t far off, either. The fi rst wave of prod-
ucts will produce color using a multicolored
fi lter—operating in much the same fashion
as the red, green, and blue subpixels in an
LCD. These products will require a small
amount of power to operate the fi lter, but the
images they display will be just as stable as
the black-and-white products. And they’ll
arrive sooner than you might think. Throw
in a persistent wireless broadband Internet
connection, and we’ll be very close to the
Young Lady’s Illustrated Primer that Neal
Stephenson dreamed up.r & d BREAKING DOWN TECH —PRESENT AND FUTURE
FEBRUARY 2007 MAXIMUMPC 61
White Paper: Electronic Paper
ILLUSTRATION COURTESY E INK CORPORATIONBOTTOM SHELL The ventral
half of the e260’s outer shell is
fabricated from aluminum.BATTERY This Li-ion battery accounts for a surprising
amount of the player’s total mass.Flash-Memory Digital
Media Player
You discover the most interesting things when you take a product apart. Who’d have
guessed that the SanDisk Sansa e260’s circuit board was actually designed by MSI?Bottom
electrodeTOP SHELL The top
half of the e260’s outer
shell is made of high-
impact plastic.TRANSPARENT FILM
This thin but incredibly
tough polymer window
protects the player’s
relatively fragile LCD.SCROLL WHEEL
This one actually
spins, unlike the track
pad on Apple’s iPod
and even more unlike
the fake wheel on
Microsoft’s Zune.BACKUP BATTERY
This button battery
protects the player’s
settings in the event the
e260’s primary battery
runs out of juice.LEDS Four lights
arranged beneath and
around the scroll wheel
illuminate it in blue.LCD This player
sports a 1.8-inch
color active-matrix,
thin-film-transistor
screen.