& the GII
This page offers an introduction to what has been variously
promoted as 'digital paper', 'electronic paper' and 'electronic
It covers -
supplements the discussion
of traditional paper (eg made from rag or wood pulp) and
background material in the Electronic Publishing guide
elsewhere on this site. The following page considers 'digital
the 1970s there have been major investments in research
regarding new ways of displaying digital information and
capturing information using a pen rather than a keyboard.
Although stylus-based personal digital assistants (PDAs)
have gaining significant market acceptance - some studies
suggest that 6% of the US online adult population has such
a device, with most frequent use relating to 'smart phones'
- work on 'electronic paper' has had little success.
Researchers have aspired to creation of a medium that has
the essential characteristics of a sheet of paper - thin,
light, flexible, shock-resistant, able to provide a high-resolution
display of text and graphics, able to accept handwritten
text, use little power and be highly durable. Have we forgotten
anything else? Oh yes, have low production costs so that
it could be priced as a 'throw-away' item.
So far the aspiration has been unfulfilled: most products
meet several requirements of that wish list but not all.
Gyricon and SmartPaper
prototype 'electronic paper' was developed
at Xerox's Palo Alto Research Center (PARC), home of the
computer mouse and laptop, in 1975. What's now marketed
was initially labelled 'Gyricon' (after the Greek for "rotating
image"). It is currently handled by Xerox's Gyricon Media
Although the expectation was that it would replace many
publications, with commuters for example uploading the daily
newspaper onto a sheet of Gyricon for perusal en route to
work, it's largely been restricted to corporate signage
(particularly for upmarket US retailers).
The technology involves a flexible transparent membrane
embedded with microscopic spheres, each with a light-coloured
hemisphere and a dark-coloured hemisphere. Small
electrical charges result in the spheres rotating to display
their light or dark side up, thereby generating a high-contrast
The technology is 'display only' - the 'screen' does not
accept input by pen or paw - and might more aptly be described
as electronic cardboard. It's mono-chromal.
An independently-developed product using membranes containing
black and white particles within microscopic liquid-filled
capsules was developed in the late 1990s by E
Ink, building on research
As with SmartPaper, patterns are created by applying a small
charge to the membrane. In essence, when the charge is applied
white or black particles inside the membrane's capsules
move to the top (ie screen-side) of those capsules, forming
black and white patterns that look like ink on light gray
paper. The 'ink' remains in position until a new charge
is applied (eg when a 'page' is 'turned'), so there is no
need for power to constantly refresh the image on screen.
(E Ink is thus different to CRT and LCD screens.) E-Ink
does not use a backlight, so that reading is dependent on
ambient light, similar to a text on traditional paper. John
Jacobson's 1997 paper
offered an early explanation of the technology.
Like SmartPaper E Ink's Electronic
Ink was initially primarily used for in-store displays.
E Ink trademarked the term 'RadioPaper' and from 2003 apparently
concentrated research into low-power lightweight
monochrome displays for personal assistants and laptops.
Those displays have been used in electronic book device,
such as the Sony Reader discussed here.
E Ink's site notes that an electronic ink display can have
a much higher resolution than current LCD screens, uses
1/1000th of the power necessary for an LCD display and can
preserve its content without power. A consumer for example
could switch off the power on and off while reading a page
of text. Sony reports that a prototype Reader in
Japan has displayed the same page for three years on a single
DataGlyphs and DigiPaper
developed but has not had much success with DataGlyphs,
sometimes promoted as "digital paper." The technology essentially
provides a watermark or steganographic identifier on wood-pulp
paper. That identifier can be recognised by a scanning device.
Under optimal conditions a one-inch square DataGlyph could
encode up to 1000 bytes of data. Promoters have claimed
that it could be used in a document management system, as
the basis of a security scheme (eg the image would be discernable
to the scanner but not to the unaided eye if the document
was photocopied) or as a barcode-style label in some form
of production system.
While humans can write on DataGlyphs paper, that ink/pencil
information rests on top of the 'glyph' and is independent
of it.a form of encoded data designed to be printed on ordinary
paper for later scanning and decoding by a computer.
Xerox PARC also developed DigiPaper,
an image-based document representation that uses token-based
image processing to obtain very high compression for bitonal
For data capture the main contender is Anoto,
developed in Sweden. It relies on specially-treated paper
and the Anoto pen,
a digital device that is tied to a wireless network. Each
pen would have a separate IP address; each sheet of Anoto
paper - whether sold as a label, a note pad or in some other
format - will be unique. Putting pen to paper results in
a unique map, that is then (in theory) transferred to and
can be retrieved from a digital memory using the wireless
Sound excessively complicated? Perhaps. The idea grabbed
the attention of geek-lifestyle magazine Wired in
early 2001 and has attracted favourable attention from competitors
such as the MIT Technology Review.
In essence, Anoto is a 2001 wireless update of the graphics
slates that appeared (and disappeared) in the late 1980s.
It allows data capture - albeit second-hand - but otherwise
is traditional paper: the display uses ink on pulp rather
than digits on a screen.
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