Samsung files lawsuit over iPhone 5 Samsung Electronics has filed court papers accusing Apple's iPhone 5 of infringing its patents, as it seeks to regain ground following a $1bn US court defeat in August. The South Korean company said on Tuesday that it had added Apple's flagship smartphone to the list of devices that allegedly misuse its wireless data technology, according to a complaint filed at a California court in April. Samsung had indicated its intention to make the amendment shortly after Apple unveiled the iPhone 5 on September 12. A person close to Samsung said that it could not rule out pushing for a sales ban on the new iPhone, although it was not clear when its complaint would be heard in court. The announcement came hours after the same US court lifted a sales ban on Samsung's Galaxy Tab 10.1 tablet device, against which Apple won a preliminary injunction in June. The court sided with Apple and ordered Samsung to pay $1bn in damages, after the California jury found that several models in Samsung's Galaxy smartphone range had infringed patents held by Apple, relating to both the external design and software features of the iPhone. However, the same court dismissed the claim that the Galaxy Tab 10.1 infringed design patents on the iPad. However, the decision will not have a big impact on Samsung's US revenues: the device went on sale in June last year and is expected to be superseded by newer models in the next few months. In contrast with the success of the Galaxy smartphones, Samsung has struggled to challenge Apple's grip on the tablet market, which is still dominated by the iPad. Samsung said: "We have always preferred to compete in the marketplace with our innovative products, rather than in courtrooms. However, Apple continues to take aggressive legal measures that will limit market competition. Under these circumstances, we have little choice but to take the steps necessary to protect our innovations and intellectual property rights. The world's two leading smartphone makers are locked in a global legal battle that has brought court cases in four continents. Despite the one-sided result in the US, other verdicts have been more even and Samsung emerged the victor in recent cases in South Korea and Japan. Analysts say the legal dispute between the two could strain the companies" close working relationship - Samsung is the biggest supplier of components for the iPhone. Apple has already started reducing the proportion of chips and screens that it buys from Samsung. Mark Newman, an analyst at Sanford C Bernstein, who previously worked for Samsung, said that Samsung's broadening of its case to include the iPhone 5 was "a defensive measure." They're doing it to give them more leverage against Apple in the rest of the litigation process. Both parties will keep fighting tooth and nail in the courtroom, but it's unlikely to result in significant product bans," Mr Newman said. Shares in Samsung closed 1.7 per cent higher on Tuesday at 1.369m won, in a flat Seoul market.