Monday, November 4, 2002		Feature

A simple touch display for the visually impaired, to be tested by the National Federation of the Blind, soon could provide access to computer-generated images, federal researchers have said.

The device comes from the National Institute of Standards and Technology, which also is well along in the creation of a reader to turn electronic text into Braille letters, said Sam Bodman, deputy secretary of commerce. The NFB has helped refine the reader, which is ready for commercial licensing, he told a news conference.

"We’re thrilled to know the federation members will be providing field testing of the (tactile display) technology," Bodman said.

"The collaboration will help prepare this device (for) the homes, schools, and workplaces of those who will greatly benefit from it."

The NFB wants visually impaired people to be adventurous, said Marc Maurer, the group’s president, but not everything is achievable at present.

"We who are blind, if we get the right training, we can manage the words," Maurer said. "If we don’t have the right devices, we don’t have the pictures and we don’t have the information we need to be competitive."

NIST has come up with such a device, said John Roberts, a project leader in advanced display technology systems at the agency.

The display relies on the same principle found in the "bed of nails" item often found in novelty stores, where an object pressed into the toy’s mass of pins leaves a recognisable image, he told United Press International.

The prototype tactile display is a set of 3,600 small pins, about 10 per inch, suspended over an early 1990s-era plotting printer, which transports a pen both vertically and horizontally to reach the desired position.

The display "prints" an image by using an extendable pointer, much like a ballpoint pen, to raise selected pins into a line drawing of the image.

"Current technology for doing this involves (devices that change shape when subjected to an electric current), and costs $ 40,000," Roberts said. "The tactile display should cost about $ 2,000 initially and probably come down from there."

Curtis Chong, NFB’s director of technology, agreed the display should be much easier to mass produce and therefore cheaper. A photocopy-like process also can produce raised images, but at a cost of about $ 2 per sheet for specially treated paper, he said.

"(The NIST display is) a fundamental beginning that could result in something really slick," Chong told UPI. "You can draw a logo or something in real time and have it raised up so that a visually impaired person can put their hand on it and say, ‘Oh, that’s what it looks like."

While a 10-dot-per-inch printed image would provide little visual information, that level of detail is about right for tactile images, said Chong, who is blind. He easily recognised the display’s renderings of the outline of Texas, and also quickly made out the stylised NIST logo.

Improving the resolution to 20 or 30 dots per inch would provide better curves, Chong said. Moving to the hundreds or thousands of dots per inch available in current inkjet printers would only add subtle details, like shading, that are meaningless for the blind, he said.

Development efforts will focus on shrinking the overall size of the display while maintaining its level of detail, Roberts said.

Blind engineers and other professionals relying on mathematics are really interested in being able to "see" graphs and other charts, he said.

The tactile display also would provide dramatic benefits in education, an area where the gap between written and graphics-based information is quite large, Chong said.

"Everyone has learned to see pictures based on some fairly intense learning curves that you get when you’re a kid—how do you look at a two-dimensional flat picture and know it (represents) a three-dimensional object? It’s not automatic," Chong said. "How (does a blind person) touch a two-dimensional representation of a three-dimensional object and know what it is? If we could get (blind) kids to feel stuff way more often, every single day in school, maybe the graphical gap won’t be so bad."