Don Frederick Widmayer, 72, a Bethesda inventor who retained patent rights on a energy-saving lighting fixture after an eight-year legal fight that was appealed to the U.S. Supreme Court, died at his Bethesda home Oct. 14 after a heart attack.

It was a case that pitted Mr. Widmayer, a recognized authority on fluorescent lamp technology and president of his own research and development firm, against a battalion of high-priced intellectual-property lawyers.

Having exhausted his funds during the first years of litigation, Mr. Widmayer primarily represented himself during the dispute, which centered on an invention called Flexiwatt, an electronic device that allows fluorescent fixtures to automatically adjust their output of light depending on the presence of daylight.

He first developed the basics of the technology in the 1960s, while working on a light table to view aerial reconnaissance photographs. In 1984, an official of a company with which he had a licensing agreement to produce and market Flexiwatt filed a patent on a modification of the technology.

After the U.S. Patent Office awarded the rights to the invention to Mr. Widmayer, the company, Conservolite Inc., filed a suit of patent infringement against him and took the case to the federal court.

After several court rulings, appeals and countersuits, the Supreme Court in 1994 declined to hear the case, allowing an appellate court ruling in favor of Mr. Widmayer to stand.

With a victory in his pocket, Mr. Widmayer moved on to gain product acceptance for Flexiwatt, putting on demonstrations for potential clients. Last year, he started a new company, Precision Lighting Inc., and Flexiwatt received the Product of the Year award from the Maryland Society of Professional Engineers.

Flexiwatt is being test-marketed at American University and Alexandria public schools, according to Mr. Widmayer's wife, Joanne Wright Widmayer.

Mr. Widmayer was a native of Michigan. During World War II, he served in the Navy as a radioman in the Pacific. He came to Washington in 1953, then graduated from the University of Maryland with a degree in electrical engineering before starting his company in the early 1960s.

He served as president of the Potomac Rotary Club and was a founder of the North Bethesda Rotary. He also was a past president of the D.C. Chapter of the Society of Photographic Scientists and Engineers and was a member of Kenwood Golf and Country Club.

In addition to his wife, of Bethesda, survivors include a daughter, Jean Widmayer Krafft of Bethesda; two brothers; two sisters; and a grandson.