Information Technology Reference
In-Depth Information
that the camera might not see the pattern dots at positions where other content is
printed. To cope with this problem, the Anoto technology relies on a smart solution
that leverages an optical characteristic of toner and ink. Some toners absorb infrared
light and thus appear in the image of the infrared camera in black. These toners are
used for printing the dot pattern. Other toners do not absorb infrared light. While
these toners are visible to the human eye, they are not visible in the camera image.
These toners can be used for printing contents other than the dot pattern. These con-
tents do not interfere with the dot pattern in the camera image. The printer requires
toner (or ink) that has these characteristics. It happens that the black toner (K) used
in many laserjet printers typically absorbs infrared ink, while cyan (C), magenta (M)
and yellow (Y) toners do not. This allows printing the dot pattern with K toner, while
other contents are printed by using only C, M and Y colors. The Anoto pattern and
other contents can be printed in two separate steps or in one single step. Anoto has
tested printers of diverse manufacturers and has published a list of Anoto-certified
printers. If the pattern is to be applied to larger paper products, it can be printed with
some selected inkjet plotter models.
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Pen Models
Anoto pens are produced by several manufacturers. The Anoto/Maxell
DP-201 and the Logitech/Destiny io2 support USB batch processing and Bluetooth
streaming. The Anoto ADP-301 supports only Bluetooth streaming, but features a
lower latency than the DP-201. This makes it the product of choice for applications
with hard real-time constraints on input. Finally, the Anoto ADP-501 features a
thicker pen tip instead of the thin ballpoint tip. This provides for use on flipcharts
and whiteboards. Several older pen models are discontinued, most notably Logitech
io and io2, Nokia SU-1B and Nokia SU-27W.
These standard models suffer of several shortcomings that will be discussed in
the following: pen feedback, erasing of contents and use as a stylus on displays.
Pen Feedback
The standard models do only capture and digitize pen traces to
transfer them to a computer. They do not interpret them and therefore cannot pro-
vide system-specific feedback, even though all pens feature LEDs and some of them
can vibrate. Moreover, the Bluetooth connection does not offer any back-channel to
control the pen, so applications cannot generate feedback given by the pen. Liao et
al. [76] extended one of these pen models with auditory, tactile and visual feedback
and explored with that prototype several pen-based feedback mechanisms. Recently,
several new pen models have been commercialized that include additional process-
ing capabilities and output devices. These pens are able to interpret pen traces and
react to user input. The Fly Fusion Pentop Computer
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has a built-in speaker. It reads
out the translations of handwritten words, can be used as a calculator and plays MP3
files. The more recent Fly Tag Reading System aims at helping kids learn to read.
It features a digital pen that reads out the passages of a topic the user points to. The
Livescribe Echo Smartpen
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(Fig. 2.7) has a built-in microphone, speaker and an
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For instance the plotters of the Canon imagePROGRAF series (iPF8000, iPF8300, iPF9000,
iPF9100) provide quite good results on diverse types of paper and foils.
12
http://www.flyworld.com
13
http://www.livescribe.com
