Flexible Display Screens
Readied for Production
Roll 'Em, Fold 'Em, Stick 'Em in Your Pocket:
Long-Envisioned Plastic Sheets Will Make E-Newspapers, E-Books a
Reality
By
Rick Weiss
Washington Post Staff
Writer
Monday, February 2,
2004; Page A08
The trail has disappeared and let's face it, you're lost in the woods.
But luckily you've got your trusty map rolled up in a pocket. You unroll the
plastic-coated sheet . . . it's blank -- until you turn the power on.
Suddenly the curly page jumps to life with a detailed screen display,
including a selection of topographic maps showing the way back. Later, at your
car, you unfurl the same sheet, this time to check out restaurant reviews for
local eateries.
Scenes like this one have long been imagined by techno-optimists. But
reality has repeatedly delayed the introduction of flexible electronic displays.
Even today's thinnest and fanciest display screens for laptops and digital
assistants are topped with a layer of glass or plastic that cannot be folded,
bent or mutilated -- much less rolled up into a handy little tube.
But after years of unabashed hype and dashed hopes, truly flexible
displays are at last being ramped up to commercial production. Among the uses
that manufacturers foresee are electronic newspapers that can be folded or
rolled when not in use and then opened to display the latest news; flexible
strips for store shelves that display constantly updated price and product
information; and watch bands or bracelets that offer streaming news or other
information.
Some companies are even considering working the technology into lines
of clothing. Forget those low-tech embroidered Gap or Gucci logos on your
shirts, said Barry Young, vice president and chief financial officer for
Austin-based DisplaySearch, a market research company that tracks the flat panel
display industry. We're talking about a Times Square-style news crawl moving
across your chest: G . . . U . . . C . . . C . . . I.
"Now we'll have to pay to be a billboard," Young quipped.
Flexible-display blouses are still some years off. But a more modest
rollable display -- the first to be truly mass-produced -- is now being churned
out at the rate of 100 per week and may reach production levels of 1 million a
year by the end of next year, said Bas J.E. van Rens, general manager of Polymer
Vision, the division of Royal Philips Electronics of the Netherlands that makes
the display.
The device is a rectangular screen just three times the thickness of a
sheet of paper and measuring five inches diagonally. It curls into a tube less
than two inches in diameter and may soon coil to the diameter of a fountain
pen.
With the exception of some invisibly fine gold wires, the circuitry
that's inlaid into this flexible page is completely plastic. An internal layer
of "electronic ink drops" creates black text on a white background, giving the
plastic sheet the look of a paperback page.
The whole thing weighs just 3.5 grams, or about the weight of 11/2
pennies. When it is dropped, van Rens said, it doesn't shatter into a heap of
glass shards and electronic guts. "It just flutters to the ground," he said.
Flexible Display Screens Readied for Production
Two advances underlie the arrival of flexible computer displays. One
involves improvements in electronic paper, or "e-paper" -- thin plastic sheets
packed with closely spaced black and white dots, or pixels, that can be
electronically rearranged many times per second to create ever-changing
messages. The other involves breakthroughs in the field of "organic
electronics," in which scientists are making transistors and other electronic
components out of plastic instead of rigid silicon and metal.
The Polymer Vision screen, described in the February issue of the
journal Nature Materials, uses e-paper technology developed by E Ink, a
Cambridge, Mass., company. Embedded in a thin sheet of plastic are tiny capsules
smaller than the period at the end of this sentence, each filled with thousands
of particles, some black and some white. The black and white specks have
opposite electronic charges, so depending on whether a positive or negative
charge is applied to that capsule, either the white or the black specks leap to
the sheet's visible surface at that spot.
By applying positive or negative charges in pinprick patterns across
the "page," the black and white specks can be arranged to make letters and words
that look just like those printed with ink on paper.
Unlike standard computer and PDA displays, which generate tiny points
of light, the E Ink system simply reflects ambient light off its white
background, like a newspaper or book. So it is easily read outdoors in bright
sun and at virtually any reading angle. Light-emitting screens are difficult to
read in bright places and must be viewed fairly straight on.
The E Ink system also draws far less power than light-emitting systems
because it needs energy only to set the image, which remains visible without
additional power until it's time to "turn the page" -- that is, call up the next
image.
A thin layer of plastic underlying the display contains the electronics
-- including a paper-thin array of 80,000 plastic transistors, each of which is
a minuscule electrical switch that can create a dot of white or black on the
overlay.
Similarly flexible plastic electronics are being made by other
companies. Plastic Logic of Cambridge, England, uses specialized dot matrix
printers to literally print its circuitry onto a polyester backing instead of
etching its transistors from layers of plastic, as Philips does. And several big
corporations, including DuPont, Siemens AG and Xerox Corp., are now racing to
integrate flexible circuits into a variety of products. Prototypes typically
allow for internal storage of images (such as maps) as well as an ability to
download fresh information via either an internal antenna or cell phone. The
display would feature scrollable menus and a few flexible point-and-click keys
for entering commands.
Experts say flexible screens will be aimed first at specialty niches --
including the military, which, among other things, is thinking about the
technology for its uniforms -- not to say "GUCCI," but to change shades to match
surroundings and to display enemy coordinates on constantly updated wrist bands.
Stores want rollable, portable display boards with moving messages, and
radio-controlled "Sale" signs for clothing racks that can suddenly declare "10%
Off!" at the click of a computer mouse.
Consumer applications, such as e-maps and e-newspapers that roll up
like window shades, remain a few years off, but a stiff version of e-paper is
about to hit the market. This spring, Sony is expected to release an e-book
using Philips and E Ink technology -- an electronic reader about the size of a
paperback that can be loaded with a library full of literature without cutting
down a single tree. E-books would also have the advantage of being potentially
searchable by key words and could have built-in dictionaries.
Analysts envision a future in which students will trade their bulky
backpacks full of books for a single all-purpose e-text. And with the capacity
to download a few comic book programs as well, students may even free themselves
from the age-old hassle of hiding the latest issue of Spiderman comics inside
the cover while pretending to study.
See IRG research reports
