Advanced X-Ray Machine a Product of Doodling, Tinkering in Garage : Technology: Device invented by unemployed engineer eliminates fuzzy images and displays a 3-D picture almost instantly. NASA uses it to examine parts of space shuttle.

It started with a doodle on a scrap of paper.

Then came a garage-built device of surplus parts and the first blurry images of a chicken wing. Now, inventor Robert Albert hopes his extraordinary X-ray will see him into the big time.

Albert’s Digiray Corp. has sold three of its $200,000 machines, including one to NASA, and has queries from several more companies.

Success didn’t come overnight.

“We had a long period of trying to make it work,” Albert said. “I could make it work in the garage, but then when we tried to make a commercial model that was a whole new thing.”

The first inkling of success came three years ago “when people started to buy them,” said Albert, whose company moved out of the garage and into a fair sized building. It employs eight workers, including Albert’s wife and one of his sons.

What Albert invented is called a Reverse Geometry X-ray system, which as its name suggests, puts a new spin on the X-ray, discovered by Wilhelm Roentgen in 1895.

In conventional X-ray systems, the object to be viewed is placed some distance from the source of X-rays, which pass through the object and then are registered on an image intensifier or film.

The distance allows the rays to fan out, somewhat like aiming the pressure nozzle of a hose at a far corner of the garden to widen the area watered.

But that method has a drawback--”scatter” rays bounce off the object and spoil the image.

Albert came up with a way to make the X-ray source much larger, allowing objects to be placed right next to it. Rays beamed through the object are processed by a computer, which then produces an image on a screen, not on film. The computer doesn’t see the scattered rays, creating a purer image.

“They have a scratchy record, so to speak, where we have a very clear compact disc,” son Thomas Albert said.

On a recent visit to the company offices in San Ramon, about 40 miles east of San Francisco, the Alberts showed off their X-ray images as proudly as grandparents with a new set of baby pictures.

A 3-D image not only revealed a crack in an engine block, it showed how deep the crack went. A Digiray of a helicopter blade showed a failing joint. A surgeon’s hand showed not only bones, but tissues, tendons and the ghostly outline of a latex glove. A cat’s paw was complete with wisps of fur.

Advantages of the Digiray are that it produces virtually instant images, can pinpoint specific areas, such as a computer chip on a circuit board, and can produce 3-D images. A miniature detector built by Albert can be used to fit into tight places, such as aircraft fuselages and the welded vessels of the space shuttle.

One early customer is a fan.

“It’s a home run,” said Douglas Froom of McClellan Air Force Base, which is using the machine to, among other things, check the wings of Stealth fighters.

Albert, who follows a trail of Northern California garage inventors like Steve Jobs of Apple Computer, started out as a nuclear physicist. He worked for the space science lab at UC Berkeley until 1974 “when I decided that I wanted to do something on my own.”

He added, wryly, “I was helped by the fact that they laid me off.”

The Digiray was something of an accident, he said.

“I was playing around on a piece of paper. I drew this picture to make a better spectrometer (an instrument used for measuring spectral wavelengths). After I looked at it for a while, I said, ‘This would not work. It would be a terrible spectrometer, but it might be a good X-ray system.’ ”

Armed with a batch of surplus parts, Albert put together a device and started trying to produce images.

His first pictures were of a chicken wing “borrowed from my wife out of the refrigerator.” He keeps the blurry images for sentiment, although he says “when I look at them today I can’t figure out why I continued on.”

Recent successes are encouraging, but Albert misses his doodling days. His goal now is to get the company to the point that he can step back from day-to-day operations.

“I want to go back to R&D;,” he said.