The Apple vs Samsung patent-based U.S. case is set to start on July 30, but until then we already have various tidbits to show you from the cases each company will try to prove in court in this legal clash of the titans – and they surely have a complex relationship.

The two companies are fighting for market share and profits in the smartphone and tablet business, but they are also bound by a multi-billion dollar component supply partnership. Also important is the fact that they are facing each other off in more than 50 cases spread across 10 countries, and they’re all mobile-related.

Apple argues that Samsung Galaxy-branded smartphones and tablets are violating its iPhone and iPad patents and designs, while Samsung says that Apple is infringing with various iOS products its own 3G patents – which happen to be FRAND, or standard essential patents.

Apple has scored a few victories against Samsung in pre-trial rulings including a couple injunctions in the U.S. against the Galaxy Nexus and the Galaxy Tab 10.1 – albeit the Galaxy Nexus is still selling in the region after a second Samsung appeal succeeded to stay the initial decision, but also an adverse inference jury instruction. The company also won a few days ago a EU-wide injunction against Galaxy Tab 7.7 sales but also lost an injunction in the UK against the Galaxy Tab 10.1.

What’s worth remembering is that while all these verdicts came out in the last few weeks, Google decided to officially help Samsung in its fight against Apple, especially after the Galaxy Nexus sales ban was obtained in the U.S. by the iPhone maker.

But it turns out that Apple lawyers may also use Google against Samsung, at least according to Apple’s brief which mentions some Samsung interesting documents:

“Samsung’s documents show the similarity of Samsung’s products is no accident or, as Samsung would have it, a ‘natural evolution,’” Apple argues in its brief. “Rather, it results from Samsung’s deliberate plan to free-ride on the iPhone’s and iPad’s extraordinary success by copying their iconic designs and intuitive user interface. Apple will rely on Samsung’s own documents, which tell an unambiguous story.”

Apparently these documents reveal that the Search giant warned Samsung in the past that some of its Android products are too similar to the iPhone and iPad:

•  In February 2010, Google told Samsung that Samsung’s “P1” and “P3” tablets (Galaxy Tab and Galaxy Tab 10.1) were “too similar” to the iPad and demanded “distinguishable design vis-à-vis the iPad for the P3.”
•  In 2011, Samsung’s own Product Design Group noted that it is “regrettable” that the Galaxy S “looks similar” to older iPhone models.
•  As part of a formal, Samsung-sponsored evaluation, famous designers warned Samsung that the Galaxy S “looked like it copied the iPhone too much,” and that “innovation is needed.” The designers explained that the appearance of the Galaxy S “[c]losely resembles the iPhone shape so as to have no distinguishable elements,” and “[a]ll you have to do is cover up the Samsung logo and it’s difficult to find anything different from the iPhone.”

These are all points that Apple will make in court, and we’re certainly interested what the jury will think.

This sort of evidence is all the more intriguing in this case as Judge Lucy Koh, who presides the U.S. case, famously asked Samsung counsel in one of the early U.S. face offs to recognize the Galaxy Tab from two tablets she was holding, one being an iPad. The lawyers were not able to identify the tablet of their client “from that distance” – or about 10 feet away – although they finally managed to provide the right answer.

We’ll be back with more news from this battle of giants in the near future.