Sun-Proof Displays Help Users See Clearly

Computers For The Rest of Us.

September 30, 1997

When George Heisel sailed to the Bahamas this spring, he not only had the spray in his face, he also had the sun at his back. And that was the problem. Up on the fly-bridge of his 61-foot yacht, there was so much light he couldn't read his navigation monitor.

"It was useless," he grouses.

Anyone who has lugged a laptop computer outside knows the feeling. The display, which looked so clear and bright inside, is dim and unreadable in direct sunlight. Maybe it's Mother Nature's way of saying we're working too hard.

But in many fields of work, outdoor computing is becoming indispensable. Farmers, real estate agents, search-and-rescue personnel, even high-tech soldiers are logging on to improve their effectiveness. One day, most drivers may too.

For a time, hand-held computers used monochrome screens, which are more easily readable in the sun. But increasingly, outdoor workers demand color displays, especially for satellite-guided navigation. If you've ever tried to find your way on a black-and-white map, you know what I mean: color maps convey more information.

Fortunately, Mr. Heisel happened on a specialized marine display called the DiscoveryMate. It's readable just about anywhere. When I hooked one up to a Toshiba laptop the other day and pointed both units into the sun, the Toshiba was unreadable. But the DiscoveryMate displayed every color clearly (except some yellow and light green text).

Its secret: The display is roughly 10 times brighter than laptop screens. Most portable computers only use one or two light tubes (to conserve battery power) and place them on the edges of the display (to conserve space). The DiscoveryMate uses 10 light tubes and puts them directly in back of the display. Mr. Heisel used one this summer to sail some 3,000 miles, which allowed him to use his computer as his primary navigation system.

Cascade Technology Corp., which makes the unit, is trying to move into other markets. Navy researchers have tested its units. An agricultural computing company is interested.

There are two big drawbacks: the weight of the monitor (10 pounds) and its cost (above $3,000).

Other companies are developing alternative sunlight-readable displays, attracting funding from the Air Force and other branches of the military. In Maple Park, Ill., David Larson has experimented with several sunlight-readable displays. As director of advanced farming systems, software, and services for Case Corp., which makes agricultural implements, he's interested in putting computer monitors on tractors and such. But he rejected the specialized sunlight-readable displays as too bulky and costly. Instead, he has farmers using more than 60 hand-held computers in the field.

The machines, made by the likes of Hewlett-Packard, run a portable version of Microsoft's operating software called Windows CE. "It's fantastic," he says of Hewlett-Packard's bright display. "It's better to view it in the direct sun than in an office."

It's not clear what display technology the auto industry will use. Dashboards usually can be configured to protect the display from sunlight. But if drivers begin to demand special navigation systems with color maps, then sunlight-readable displays could become important, says P.K. Purkayastha, a program manager at Ford Motor Company.

For the moment, Ford is trying out Cascade's superbright screens. The screens, which display sensor readings for everything from acceleration to engine temperature, need to be readable no matter what the light conditions. "The sun isn't going to go away and you cannot hide from it all the time," Mr. Purkayastha says.

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