The mammoth Apple-Samsung patent trial is winding up in the US, setting the stage for a verdict that could have huge implications for the hot market in smartphones and tablet computers.
US District Judge Lucy Koh began reading instructions to the nine-member jury in California, as lawyers for the two tech giants readied closing arguments.
Apple, which accuses the South Korean electronics giant of copying the iPhone and iPad too closely, is seeking damages of up to $US2.75 billion ($A2.64 billion) and an injunction that could knock some Samsung products off the US market.
Even a delay in sales could endanger Samsung's position in the US market, where it is currently the top seller of smartphones.
Samsung has countered by arguing that its patents on wireless communication were infringed by Apple, and is demanding up to $US422 million from the Silicon Valley manufacturer.
One decision Judge Koh made about the jury instructions levelled the playing field in Samsung's favour.
Originally, the jury was to hear Samsung had broken rules by deleting emails which could have been used in evidence. But on Monday the judge found that Apple had made similar mistakes and should get the same treatment.
The lawyers agreed to simply not have the jury hear anything about the issue, and it did not come up in instructions.
The trial is wrapping up after 10 days of testimony over three weeks, in which Apple put its own designers and executives on the stand, along with experts, all of whom accused Samsung of illegally copying Apple designs.
Samsung witnesses said meanwhile that they had come up with the designs and icons they used on their own.
However, internal Samsung documents introduced as evidence did show they were aware that they were behind Apple's iPhone when it came to some user-interface features.
One Samsung designer described the gap between the iPhone and a Samsung smartphone as the "difference between Heaven and Earth".
The case has been a particularly heated one, with lawyers from both sides filing hundreds of pages of objections against particular exhibits and witnesses.
This is one of several court cases around the world involving the two electronics giants in the hottest part of the tech sector -- tablet computers and smartphones.
While the results so far have been mixed in courts in Europe and Australia, Samsung has a lot at stake in the US case, which could result in large damages or injunctions against its products in the American market.
A survey by research firm IDC showed Samsung shipped 50.2 million smartphones globally in the April-June period, while Apple sold 26 million iPhones. IDC said Samsung held 32.6 per cent of the market to 16.9 per cent for Apple.
Samsung is the leading maker of smartphones using Google's Android operating system, which has become the most popular platform despite complaints from Apple that it has infringed on its patents.