Apple has lost an appeal at the High Court over its claims Samsung's Galaxy Tab was to similar to its iPad tablet.
The world's biggest tech company failed to convince the court that the device was substantially the same as its own designs.
The decision is the latest in a long-running series of lawsuits between the two companies, ranging from the look and feel of Apple's operating system, the design of its iPhone and iPad products and the technologies behind them.
Apple lost the original case in July, after a judge decided the Galaxy Tab was "not as cool" as the iPad.
The judge had ruled that the products were different enough to avoid infringement, and was asked to pushing ads on its website clarifying that Samsung did not copy its designs.
They key test is whether two products convey the same "overall impression on the informed user".
Judge Colin Birss said in July that from the front the two products were "very, very similar", but said "[Samsung's] do not have the same understated and extreme simplicity which is possessed by the Apple design. They are not as cool. The overall impression produced is different."
Apple went to the Court of Appeal to protest the decision, but failed to overturn the ruling. The appeal was dismissed today by Lord Justice Longmore, Lord Justice Kitchin and Sir Robin Jacob.
In today's ruling, Sir Robin said: "Because this case (and parallel cases in other countries) has generated much publicity, it will avoid confusion to say what this case is about and not about.
"It is not about whether Samsung copied Apple's iPad. Infringement of a registered design does not involve any question of whether there was copying: the issue is simply whether the accused design is too close to the registered design according to the tests laid down in the law."
He added: "So this case is all about, and only about, Apple's registered design and the Samsung products."
Samsung said in a statement: "We welcome the court's judgment, which reaffirmed our position that our Galaxy Tab products do not infringe Apple's registered design right.
"We continue to believe that Apple was not the first to design a tablet with a rectangular shape and rounded corners and that the origins of Apple's registered design features can be found in numerous examples of prior art.
"Should Apple continue to make excessive legal claims in other countries based on such generic designs, innovation in the industry could be harmed and consumer choice unduly limited."