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1970's radio-frequency ID invention could eliminate use of bar codes

By DEAN TAKAHASHI
Knight Ridder Newspapers

GARY REYES / SAN JOSE MERCURY NEWS Charles Walton looks through a working model of a card-key door lock at his home workshop in Los Gatos, Calif. Walton invented Radio Frequency Identification Device (RFID) technology in the early 1970s.

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One of Silicon Valley's unsung inventors, Walton has patents on radio-frequency identification, or RFID, which 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. Using radio waves, the chips transmit information about products' location and use to a central computer.

Libraries are using RFID to keep tabs on books, while hospitals embed radio chips on pharmaceutical bottles to make sure drugs are not misused. A Barcelona nightclub scans RFID chips implanted under patrons' skins when they want to pay for a drink wirelessly.

Popularity bittersweet

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 may well eliminate the ubiquitous bar code.

"I feel good about it and gratified I could make a contribution," said Walton, 83, a Los Gatos, Calif., resident who has a soft voice, easy laugh and slow walk.

Walton made about $3 million from patenting RFID technology. But his last royalty-bearing RFID patent expired in the mid-1990s, meaning that he won't share in the potentially gigantic 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 referenced by 48 later inventions.

"For RFID, this is a pretty darn fundamental patent," said Bruce Sunstein, a Boston patent attorney.

Ham-radio fan

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 his own 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 open by waving a key card in front of a reader.

Walton still has a working mockup of the door-lock reader that he used to pitch Schlage. His first RFID card key was passive, meaning that it burned no battery power itself 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 advances in chip miniaturization.

Ken Cecil, a 65-year-old retiree in Escondido, Calif., remembers working with Walton on the Schlage products, making key cards by hand and constantly dreaming up new uses for the technology.

"There was life before Charlie in terms of inventions, but his got it off the ground," Cecil said. "Charlie was brilliant, so far ahead, and uncompromising."

Reaping rewards

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 eventually 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 two-acre lot in the hills above Los Gatos.

Evidence of his creative mind abounds. He has a koi pond with a viewing area that allows visitors to go down some steps underground so they can see the fish underwater. He rigged an automated awning to shield the house from the sun and a water slide that runs into a Jacuzzi. A pulley system raises and lowers a table with a model railroad that his three kids and five grandchildren have all played with. He's working on a way to catch a bunch of gophers in a trap all at once.

Walton also helped finance the building of a lighthouse, which bears his name in the Santa Cruz, Calif., harbor, and he sponsors contests in which high-school students write essays about peace.

What's his line?

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 slipped 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."

And pretty soon, it will be.

Copyright © 2004 The Seattle Times Company

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