Samsung began its half of the trial by defending itself from Apple's allegations, but now it's downshifted into its countersuit claims. The company's legal team called Dr. Woodward Yang, a professor at Harvard's School of Engineering and Applied Sciences, who had performed an analysis of three Samsung utility patents, and found that Apple infringed them with multiple devices.

The '460 patent protects elements of email and photo browsing in a camera-equipped device. Specifically, it covers three different functions: sending a text-only email, sending an email with an attached photo, and stepping through different photos in a gallery mode. According to Dr. Yang's testimony, the iPhone 4, 3G, and 3GS — along with the iPad 2 and fourth-generation iPod touch — all infringe the patent on both iOS 4 and iOS 5.

Scroll keys still count

He showed a video of a user performing the first two functions, but had to clarify when it came to third. The language of the patent specifies navigating through images "through the use of scroll keys." The iPad 2, however, only uses swiping when moving between images in the Photos app. Yang said the patent still covered the iPad's implementation under the "Doctrine of Equivalents" — a legal concept that allows patents to cover items that present equivalent, if not literally identical, functionality.

Photo navigation is at the heart of the second patent as well; essentially, the '893 patent describes the ability to browse photos in a gallery, jump to a camera application to snap a picture, and return to the gallery at the point you left it. Yang showed a demo in which a user photographed a piece of fruit and returned to the Photos app, enthusiastically telling the jury that "before this invention you'd see the picture of the orange." Yang stated that the same set of devices infringed the patent, all save the iPhone 3G (that phone received a limited subset of functionality compared to other iOS 4 devices, which could account for the discrepancy here).

FaceTime pulls the iPod touch back in

The broadest patent — and the one that Samsung may have the most difficult time convincing the jury is legitimate — is one that covers the ability to play music in the background on a mobile device while performing other functions. The patent specifically states that it covers a "pocket-sized mobile communication device," which takes the iPad out of contention. Yang said the presence of FaceTime on the fourth-generation iPod touch qualified it as a communications device, however.

Apple attorney William Lee then followed the same strategy that Samsung employed with Apple's experts: attempting to discredit and undermine. Lee asked Yang about one of Samsung's trial documents, in which the company was to list all of its own devices that used the patents in question. For the email and photo bookmarking patents, Samsung listed not a single phone or tablet, with Yang admitting "The document speaks for itself." Lee then played deposition testimony from one of the inventors of the '460 patent, who admitted that some the materials relating to the invention's creation had been destroyed.

The jury remained engaged, even as both sides delved into the minutiae of the '460 patent language. The court just broke for lunch, but we'll be back when things resume this afternoon.