A US appeals court Monday upheld most elements of the blockbuster patent case in which Samsung was found to have violated Apple iPhone patents, but invalidated some of the damages.
The appellate panel in Washington gave Samsung -- ordered by a jury to pay $930 million for patent infringement -- a partial victory by ruling that Apple cannot collect damages for Samsung's copying of the look and feel of the iconic smartphone.
The latest decision sends the case back to a California federal court to recalculate damages.
The ruling could affect as much as $382 million awarded to Apple on grounds the South Korean electronics giant hurt Apple's image by copying certain design features of the iPhone.
The invalidated awards affect Apple's contention that Samsung violated the "unregistered trade dress" or design components of the iPhone such as "a rectangular product with four evenly rounded corners."
The court said Apple should not be awarded damages for these items because these were not purely design features of the brand, but rather a functional element of the smartphone.
If the award were allowed to stand, the court said, Apple could have a "perpetual monopoly" of features which are needed for smartphone operation.
"Trademark law allows for a perpetual monopoly and its use in the protection of 'physical details and design of a product' must be limited to those that are 'nonfunctional,'" the appeals court said.
But the court upheld the damages violation of Apple's registered design patents and other technologies such as scrolling and zooming on a smartphone.
Neither company had an immediate response to an AFP query for comment.
In the long-running case between the world's two biggest smartphone makers, patents at issue in the case involve unlocking touchscreens with slide gestures, automatically correcting words being typed, retrieving data sought by users and performing actions on found data such as making a call after coming up with a phone number.
Samsung devices targeted by Apple include more than half a dozen smartphones from the Galaxy line, along with the Galaxy 2 tablet.
The case filed in 2012 was part of a series of patent battles around the world. Last year, the two firms agreed to end patent battles outside the United States.