March 05, 2008, 9:43 AM — If you think the iPhone's touch screen is cool, imagine a device that actually
sees, reflects and responds to your fingers touching the back of the device.
A prototype of that capability was among many that Microsoft
Research showed off at TechFest, Microsoft's annual display of research
projects at the company.
LucidTouch isn't very practical in
its current form. It's a large handheld computer with a small video camera
attached on an arm about a foot's length off the back of the device. But the
technology that enables it could easily change now that the concept is proven,
said Patrick Baudisch, a researcher at Microsoft.
The current setup includes a touch sensor layer on the back of the device.
That senses when a user's fingers are touching it. The camera attached behind
it sends an image of the user's fingers to the device, where the image is overlaid
lightly, like a shadow, on the screen. Baudisch calls it "pseudo-transparent."
In his prototype, he showed a map on the device screen. Moving his fingers
on the back of the device, he could choose an item on the map. The concept solves
the "fat finger problem," where your finger covers up the actual spot
that you're trying to touch on the screen, he said.
The invention would be particularly useful on very small devices. For example,
a watch with a touch screen would be very difficult to use with a finger because
users' fingers are quite large relative to the size of the small screen. With
LucidTouch, a user could touch an area on the wristband of the watch instead
to make choices on the watch face.
The clunky camera arrangement in the prototype might be replaced by a couple
of other technologies, including one that another group is working on that would
use infrared to pick up finger movements, Baudisch said.
Microsoft researchers also showed off a couple of ideas that use wireless technologies.
One group envisions using standard cell phones to help people choose their routes
through traffic.
The concept uses phones already on the market that contain GPS (Global Positioning
System), microphones and accelerometers. Those sensors are used to collect data
about phone users' progress as they travel around a city in a car, sending that
information back to a central site that interprets it.
Accelerometers in phones are currently used to detect when a phone is tilted
in order to shift the display from landscape to portrait mode. But in this application,
the accelerometer is used to sense how often a driver has to hit the brakes,
said Ramachandran Ramjee, a Microsoft researcher. The microphone can pick up
the sound of the car horn, a possible indication of congestion. The accelerometer
can even detect when a user hits a pothole, so the phone could identify issues
for road crews.
The data the phone collects is sent wirelessly to a site that compiles it so
that users can check the site to find out where there might be congestion on
the roads.
"GPS might be good enough in Seattle, but in Bangalore, where traffic
is chaotic and there is lots of honking and braking, it would be great to identify
this automatically," said Ramjee.
Another wireless invention from Microsoft researchers could help improve the
way devices such as the Zune use Wi-Fi networks. While many engineers have worked
on systems for optimizing the use of radio spectrum, this one is different,
said Thomas Moscibroda, a Microsoft researcher. The project he is working on
dynamically narrows the wireless channel that a device is using. Typically,
Wi-Fi devices use a 20 MHz-wide channel. Microsoft's software, however, can
dynamically adjust that down to 5 MHz or 10 MHz, depending on the application.
Using less of the channel cuts the power consumption of the device and improves
range, although it throttles the throughput. In a practical application, a Zune,
for example, might use a very narrow channel to look for other nearby Zunes.
When a user decided to send a song via Wi-Fi to a friend, the Zune could automatically
switch to the full 20 MHz channel to speed up transmission of the song.
Moscibroda and his colleagues used standard hardware components for the Wi-Fi
project and combined them with firmware they developed.
