Hank Hogan, email@example.com
PITTSBURGH – With apologies to William Shakespeare, all the world’s a pad and
all devices merely mice. At least, that could be the case if researchers Chris Harrison
and professor Scott E. Hudson of the Human-Computer Interaction Institute at Carnegie
Mellon University have their way. The duo has shown how gadgets too small for ordinary
input methods can function as their own pointing devices, thanks to the latest in
inexpensive optical sensor technology.
The approach could make possible much smaller audio players, phones
and other gear, Harrison said. “If we can get rid of screens and buttons,
we could make devices that are the size of a couple of pennies.”
Optical sensor technology mounted
on the bottom of a small device provides it with mouselike pointing ability that
makes input easier. Courtesy of Chris Harrison, Carnegie Mellon University.
Harrison, a graduate student, noted that getting information into
electronic devices presents a fundamental challenge. Although electronic devices
have gotten smaller, people have not. As a result, buttons and screens must be a
certain size, placing a lower limit on the size of devices.
The solution devised by the Carnegie Mellon researchers is to
change the input method. Conceptually, it is the same as turning a device into a
mouse, with optical sensors mounted on the bottom of the device. With two sensors,
this approach enables tracking X and Y movement, as well as rotation, on surfaces
ranging from tabletops to shirtsleeves to the palm of a hand. Virtually any flat
surface will work.
This tactic of turning devices into mice offers a number of advantages.
One is that targeting with pixel-level accuracy is possible – something that
cannot be done with comparatively fat fingers working a touch screen. Also, getting
fingers off a screen improves the visibility of its output. A third plus is that
it can transform a surface into a virtual control space, with some areas designated
for functions such as horizontal or vertical scrolling.
The approach takes advantage of the sensor technology behind today’s
optical mice. Over the past few years, the cost of such technology has dropped significantly.
So, too, has its size. At the same time, the precision of the sensors and their
ability to pinpoint a location have remained high.
The sensors and associated technology have another attribute that
makes them useful in a handheld or portable device, Harrison said. “They consume
almost no power and are fantastically precise.”
He noted that simply slapping sensors on a device isn’t
enough, however. The technology must be married to software, other hardware and
the right interface to be effective. Harrison and Hudson presented a prototype at
the April 2010 Association for Computing Machinery’s annual Conference on
Human Factors in Computing Systems in Atlanta.
In their prototype, they used the technology for gestures, with
software that understood flicking and twisting. They demonstrated an audio player,
with users able to scroll through a list, select a song and adjust the volume. All
of this was done without the use of buttons.
Tests done with eight college-age subjects produced positive feedback.
Certain motions, in particular those involving twisting, were particularly popular.
The physical nature of the motion, such as flicking, also appealed to some of the
As for the future, Harrison noted that talks with manufacturers
to bring the technology to the mass market are under way. The approach could end
up in a cell phone, which has the processing power to handle the interface.
With regard to the sensor technology itself, it’s good enough
for many applications today but could be improved, Harrison said. “Further
miniaturization is always welcome.”