The U.S. Patent and Trademark Office dealt Apple a hefty blow in its ongoing patent war with Samsung this month, invalidating a patent for the design of the iPhone’s front face cited in a lawsuit that won Apple more than a half-billion dollars in a federal court earlier this year.

Patent No. D618,677, which essentially covers the front of the iPhone 3G, was invalidated on multiple counts by the USPTO in a non-final decision on Aug. 5, according to FOSS Patents, on grounds Apple failed to sufficiently describe the design.

“While technically non-final, the odds are long against Apple getting this patent, shortly referred to as ‘D’677’ in the Samsung litigation, upheld,” Florian Mueller of FOSS Patents wrote, citing the USPTO’s lengthy deliberation time over the re-examination request, likely filed by Samsung, as reason it’s likely to stand.

The USPTO’s Central Reexamination Division found the patent was twice rejected for obviousness — once in connection with another published patent application, and once for novelty.

Apple originally submitted the patent in November 2008, and cited two of its previous patents to give D618,677 a protection date beginning January 5, 2007, with which it could file infringement complaints against companies with similar designs.

In essence, Apple attempted to patent a design that had become widely popular in smartphone design within those two years after the fact. According to USPTO, Apple failed to aptly describe the patent in enough detail to qualify for the additional two years.

The patent was cited in conjunction with others in a case tried before the U.S. District Court for Northern California, where nine jurors found Samsung infringed on six out of seven Apple patents — including the rectangular shape and rounded corners of the iPhone and the shape of its app icons — leaving Samsung on the hook to pay Apple an initial damage assessment of $1.05 billion.

RELATED: Why Apple’s Patent Win Against Samsung is a Loss for Consumers and Innovation

In an appeals ruling in May the U.S. Federal Circuit Court of Appeals reduced the California court’s damage assessment to $548 million after throwing out patent infringement claims for certain “trade dressing,” including the rectangular shape and rounded corners of the iPhone, and the iPhone 3 and 4’s app icon shape and placement, which Apple alleged was copied in Samsung’s Galaxy handset designs.

The court upheld awarding Apple damages based on the value of the company’s entire product — in this case, the entire iPhone — rather than just the value of the infringed patented features, such as the iPhone’s front face, user interface and certain utility features like tapping to zoom.

As a result, Samsung was ordered to pay the “total profit” of its infringing Galaxy products to Apple, making up the profit Apple lost in sales to Samsung Galaxy devices.

Samsung asked to court to review the decision in June, and argued letting the ruling stand would “invite overprotection and overcompensation for design patents, free from the limitations imposed in other areas of intellectual property law” and “lead to ‘an explosion of design patent assertions and lawsuits.’”

The companies are now awaiting a third trial to determine the final amount Samsung should pay. The recent USPTO decision will likely deal a significant blow to Apple’s case.

Last month a coalition of major Silicon Valley companies including Google, Facebook, Dell and others filed an amicus “friend of the court” briefing with the U.S. Federal Circuit Court of Appeals siding with Samsung, and argued upholding the ruling threatens to stifle innovation and limit consumer choice across the tech sector.

RELATED: Silicon Valley’s Biggest Companies Take Samsung’s Side in Apple Patent Fight

“If allowed to stand, that decision will lead to absurd results and have a devastating impact on companies, including [the briefing draftees], who spend billions of dollars annually on research and development for complex technologies and their components,” the group wrote.

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