Good work, Mr. Chips

Tracking: Manufacturers are embracing radio frequency identification, decades after its invention by Charles Walton.

July 08, 2004|By Dean Takahashi | Dean Takahashi,KNIGHT RIDDER/TRIBUNE

The next time you wave a key card to unlock the door to your office building, think of Charles Walton. Walton, one of Silicon Valley's unsung inventors, has patents on radio frequency identification, or RFID, that spawned those electronic door keys. Now the technology Walton pioneered in the 1970s and 1980s is poised to change the way billions of products are tracked.

Prodded by Wal-Mart and the Pentagon, manufacturers will soon be tagging everything from diapers to combat boots with RFID chips. The chips transmit information about products' location and use over radio waves to a central computer. Libraries use RFID to keep tabs on books, while hospitals embed radio chips on pharmaceutical bottles to ensure drugs are not misused. A Barcelona nightclub scans chips implanted under patrons' skins when they want to pay for a drink wirelessly.

For Walton, industry's embrace of RFID is bittersweet. Back in the 1970s, the bar code was a 25-cent solution that beat out Walton's $1.75 RFID cards as the identification system for goods scanned over supermarket checkout scanners. Now RFID might well eliminate the ubiquitous bar code.

"I feel good about it and gratified I could make a contribution," said Walton, a Los Gatos, Calif., resident.

Walton, 83, made about $3 million from patenting RFID technology. But his last royalty-bearing RFID patent expired in the mid-1990s, meaning he won't share in the potentially huge windfall that will be generated as Wal-Mart and the Defense Department begin to require their largest suppliers to put RFID tags on millions of warehoused goods.

"I'm disappointed it ran out after 17 years," Walton said of his patents. "It's not a bad law. I can't control it, and I'm not angry. I was never into stretching out the length of a patent because I was always more interested in inventing something new."

RFID had been around in various forms for years before Walton's invention of a radio-operated door lock. Earlier inventors received patents on animal-control systems, a luggage-handling system and a mail-sorting system. But Walton came up with a design that is popular today.

In his tags, a minute electrical current from a radio transceiver, or reader, wakes up a dormant card and gives it enough power to generate a response. A search shows his 1973 patent is referred to by 48 later inventions. "For RFID, this is a pretty darn fundamental patent," said Bruce Sunstein, a patent attorney at Bromberg & Sunstein in Boston.

Walton grew up in Maryland and New York as a ham radio enthusiast. He studied electrical engineering at Cornell University and went to work at IBM's research labs in 1960, where he learned the finer points of analog and digital computing. He left in 1970 to start a company, Proximity Devices, in Sunnyvale, Calif. Over time, Walton has collected about 50 patents, five of which yielded royalties.

Not everyone liked the RFID idea at first. Walton showed the technology to the board of directors of General Motors, which rejected it as too "Buck Rogers." He went a year without a salary as he shopped his invention around. Then he got lucky, licensing RFID to lock maker Schlage to make electronic locks that can be opened by waving a key card in front of a reader.

Walton still has a working mock-up of the door lock reader that he used to pitch the idea to Schlage. His first RFID card key was passive, meaning that it burned no battery power and was awakened when it came within six inches of a reader. The prototype has a 36-square-inch circuit board loaded with coiled wires and other components common in the 1970s. But there were no microchips that could house the entire RFID circuitry. Those came later, with the progress of chip miniaturization.

Once Schlage went into production in the late 1970s, the deal netted Walton a steady income each month so that he could continue inventing.

He also licensed the technology to other companies. In 1980, he received another patent for creating a digital version of RFID that could change data on the cards. Schlage's technology ended up being owned by Westinghouse. There are now about four different RFID tags in use, two invented by Walton.

"After about 10 years, I began to make good money," he said.

But it was hard to win at the inventing game. Walton modified his invention to handle automated toll collection on roads and bridges. He put the tag in the license plate with the readers embedded in the road. But Walton was edged out by a competing RFID system that put tags in windshields and readers on the sides of toll booths.

Walton became rich enough from his first RFID patent to finance his own tinkering and to buy a big house on a 2-acre lot in the hills above Los Gatos.

By and large, the world has forgotten about Walton. Back in the 1970s, he appeared on the TV quiz show What's My Line? His RFID invention was mentioned in articles about Schlage's electronic locks in Popular Science and Business Week magazines in 1973.

After that, he disappeared into obscurity, collecting royalties and enhancing his invention. Over time, the price of RFID cards fell from about $5 for a door lock card key in 1973 to roughly 50 cents for an RFID tag today. What was once affordable only for the highest-security locations in the 1970s is now a virtual throwaway technology. By 2007, RFID tags are expected to cost only about 5 cents.

Said Walton, "We had dreams of this being bigger than bar codes."

Pretty soon, it will be.

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