Has the Supreme Court killed off patent trolls?

A unanimous US Supreme Court ruling has backed away from a decades-old legal test that high-tech companies argue has sparked an abundance of obvious patents.

In a hotly anticipated decision that could make it easier to challenge patents of questionable quality, the justices called for loosening the current approach set by the US' dedicated patent appeals court for deciding when a combination of existing elements deserves patent protection.

The court wrote in a majority opinion penned by Justice Anthony Kennedy: "Granting patent protection to advances that would occur in the ordinary course without real innovation retards progress and may, in the case of patents combining previously known elements, deprive prior inventions of their value or utility."

The court heard oral arguments in November in the closely watched case, which is rooted in an obscure dispute between KSR International and Teleflex over vehicle gas pedal designs.

Technology companies were quick to praise the decision. Several Silicon Valley heavyweights, including Cisco Systems and Intel, had submitted supporting briefs urging the Supreme Court to revise the lower court ruling.

Emery Simon, counsellor to the Business Software Alliance, whose members include Adobe Systems, Cisco Systems and Microsoft, said: "There will be a better opportunity for examiners to weed out patents or applications that are not worthy of getting patents, and it will go a long way toward re-establishing patent quality."

Others were wary of the decision's broader economic implications on patent holders and voiced concern that the decision will throw the patent system into a state of confusion.

Robert Greene Sterne, founding director of the patent law firm Sterne Kessler Goldstein & Fox, said in a conference call with reporters: "I think it's very fair to say that it's going to be harder, more costly and more time-consuming for inventors to obtain US patents in all areas of technology, and particularly in areas with predictable art, as we call them, such as mechanical inventions and software and methods of doing business."

He added that "existing patent portfolios will need to be looked at, and existing relationships will need to be evaluated".

Federal law dictates that an invention cannot be patented if a person of "ordinary skill" in the same field could have come up with it. But because it's easy to claim that an invention is obvious in hindsight, the US Court of Appeals for the Federal Circuit in 1982 concocted a legal test designed to lead to a more objective conclusion.

That standard requires that for an invention to be declared obvious, some "teaching, suggestion or motivation" must exist to show that a person of ordinary skill would have thought to combine certain elements.

Critics have argued that in practice, written evidence is required to pass that test, which has made it harder to overturn allegedly obvious patents and rendered it easier to obtain them from the US Patent and Trademark Office in the first place. Technology companies say that's especially hard for them to prove because of the speedy rate at which they tend to develop new products and ideas.

Ed Black, president of the Computer and Communications Industry Association (CCIA), whose members include Google, Oracle, Red Hat and Verizon, said: "It's not written down, it's not published, it's not the subject of scholarly discussion, and that's where the Federal Circuit was basically looking."

The justices were sympathetic to those criticisms. "The diversity of inventive pursuits and of modern technology counsels against limiting the analysis in this way," they wrote. "In many fields it may be that there is little discussion of obvious techniques or combinations, and it often may be the case that market demand, rather than scientific literature, will drive design trends."

Rather than throwing out the so-called "teaching, suggestion or motivation" test entirely, the justices said they expected a number of other factors to be considered as well, namely "the inferences and creative steps that a person of ordinary skill in the art would employ".

Although technology companies were generally upbeat about the Supreme Court's latest ruling, its immediate effects aren't entirely clear.

CCIA's Black said: "This may make the holders of some lousy patents a little less interested in going the litigation route because it may well be they realise that their chances of winning are lower. I have to mitigate that comment unfortunately a little bit by saying that an awful lot of litigation goes on here that isn't expected to go to trial; it's for extortion purposes."

Anne Broache writes for CNET News.com