LAS VEGAS (AP) – A federal appeals court has upheld a ruling that invalidated key patents – for the bar code scanner and industrial robotic vision – of the late Jerome Lemelson, one of America’s most prolific and controversial inventors.

The court affirmed that 14 of Lemelson’s critical patents were unenforceable in a case brought by companies including Cognex Corp., the world’s largest maker of machine vision, and Symbol Technologies Inc., which makes bar code scanners.

The U.S. Court of Appeals for the Federal Circuit, in Friday’s ruling, backed Las Vegas federal judge Philip Pro’s finding that the amount of time it took for Lemelson’s patents to issue was unfair and they were thus unenforceable.

Lemelson filed two voluminous applications with the U.S. Patent Office in 1954 and 1956 that were the basis for patents Lemelson claimed underlied the technologies with which supermarket clerks scan prices and that allow robotic arms to place computer chips on circuit boards.

But Lemelson’s critics claimed the inventor manipulated the U.S. Patent Office, exploiting loopholes in the system that allowed him to be awarded the critical bar code and machine vision patents, the first of which was issued in 1963.

In 1998, a handful of companies sued the Lemelson Medical, Education & Research Foundation, the for-profit Nevada entity Lemelson created years earlier to enforce his patents and eventually wangle 979 companies into paying $1.5 billion in licensing fees.

After a lengthy trial, the companies prevailed in January 2004.

In his ruling, Pro said: “Symbol and Cognex products do not work like anything disclosed and claimed by Lemelson.”

But the companies never proved that Lemelson, who died in 1997, had intentionally stalled getting the patents so he could profit handsomely.

Lemelson blamed the patent office and its examiners for the delays.

The lower court said Lemelson had engaged in “culpable neglect” during the prosecution of his applications.

Rob Lemelson, Lemelson’s son, said in an e-mail that the higher court’s decision was regrettable but it did not diminish his father’s legacy that includes more than 600 patents and efforts to foster invention.

“We do not believe it detracts from the significant contributions my father made to American society through his many inventions and patents, his lifelong advocacy of the individual American inventor, and his investment, through his charitable activities, to support American innovation, invention and our economic future,” he wrote.