Apple and Samsung patent row back in court

The "slide to unlock" feature is used on every Apple mobile device

The latest round in a bitter tit-for-tat legal row between the two biggest players in smartphones will be resumed later in California.

Apple has accused Samsung of "systematically" copying distinctive features such as "slide to unlock" from its devices.

But Samsung said it was a "pioneer", and that Apple was doing the copying.

Apple is suing the South Korean firm - which is the market leader - for up to $2bn (£1.2bn).

Apple wants Samsung to be forced to pay a $40 (£24) royalty on every device it deems to be copying its software.

"Apple revolutionised the market in personal computing devices," the company said in court filings.

"Samsung, in contrast, has systematically copied Apple's innovative technology and products, features and designs, and has deluged markets with infringing devices.''

Apple has made copying claims over five features found within its iOS software.

Most recognisable to smartphone users is "slide to unlock" - in which a user slides their finger across the device's screen to unlock it and make it ready for use.

Former Google engineer Andy Rubin is listed as a potential witness in the case

The company has also claimed that Samsung stole tap-from-search technology.

An example of this is when a phone number is being shown - perhaps on a web page or within a text message - and the user is able to tap it to begin a call.

Google involvement

But Samsung has hit back at Apple's claims with two of its own.

"Samsung has been a pioneer in the mobile device business sector since the inception of the mobile device industry," said Samsung lawyers.

"Apple has copied many of Samsung's innovations in its Apple iPhone, iPod, and iPad products.''

Samsung said that it owns a patent relating to how media - pictures and video - are organised on a device.

It also said it invented a method for sending and receiving data using low bandwidth connections.

However, given that this is a case involving disputes over features in software - rather than the hardware of the devices - many have speculated that it is as much about Apple taking on Google, as it is about Samsung.

Google's mobile operating system Android powers the Samsung devices implicated in the case.

Among the potential witnesses is former Google engineer Andy Rubin, who oversaw the development of Android.

He is expected to suggest that Google was working on the features in question before Apple had filed its patents.

Video row

On Monday, the jury for the case will be chosen.

Ahead of this process, Samsung complained about a video that would be shown to jurors to explain the basics of the US patent system.

The clip goes through the ins and outs of why the patent system exists - but Samsung has expressed concern that Apple products are featured in the explainer.

Samsung said: "Because Apple's alleged innovation is a central disputed issue in this trial, it would be highly prejudicial to Samsung to show the jury - before any evidence is introduced - an official instructional video that depicts Apple products in such a context."

The company said an older version of the video, which did not have Apple products in it, should be shown to the jury instead.

The judge in the case dismissed Samsung's concerns, and the newer video will be used.

Florian Mueller, a patent analyst, said the decision "could easily give rise to a retrial".