SAN JOSE, Calif. -- One of Samsung's main strategies against Apple has been to point to "prior art," pre-existing versions of the features and designs made by others that could potentally invalidate the patents Apple is wielding against it.

In the earlier part of the trial, Samsung focused on patents for phone designs. Today, though, the company got into the guts of Apple's software -- in particular, the gestures people use to control iPhones and iPads.

Samsung brought out a pair of "fact witnesses" -- i.e. not experts -- involved in technology that predates some of the patented features found in Apple's devices. That includes something seemingly simple like photos and lists bouncing back into place, as well as the "pinch-to-zoom" gesture -- both things Apple says Samsung is infringing with its devices.

First up was Benjamin Bederson, a computer-science professor from the University of Maryland and the co-creator of LaunchTile. This zoomable network of smartphone apps was a mid-2000s invention, and one Samsung hopes will bust one of Apple's patents.

LaunchTile was released for devices running Microsoft's PocketPC mobile software near the end of 2004 (see CNET's original coverage here), and in Bederson's own words aimed to help "people access a lot information" on mobile devices It accomplished that with a screen full of thumbnail previews for mobile apps that users could zoom into to access information.

As Bederson demoed today, that involved three distinct zoom levels, which give users different levels of information depending on how zoomed in they are. That included a "world view," "zone view" and "application view." All told there were 36 such apps in this view, and users would have to find what they were looking for by navigating from that home screen:

But the patent Samsung's trying to bust isn't the home screen of icons -- something Apple is also aiming at it in this case. Instead, Samsung's going after Apple's '381 patent, which covers the "bounce-back" users get when moving something like a photo or a list beyond the area on-screen. Earlier in the case Apple accused more than 20 Samsung smartphones and 2 tablets of infringing on this technology.

Apple's lawyers jumped all over LaunchTile, demonstrating some of the key differences between how LaunchTile worked compared to the functionalities outlined in the '381 patent. This included the fact that LaunchTile's own snap back functionality did not work when reaching application tiles on the corner of the screen, or when zoomed out all the way.

Multi-touch gestures

To keep hammering at its point, Samsung brought out Adam Bogue, the creator of the DiamondTouch table, a projector-based, multi-touch gesture-enabled computing technology that came out of Mitsubishi Electric Research Laboratories (MERL). Much like Microsoft's first Surface (now called PixelSense), the idea was that users could work around a the same table, Bogue explained.

MERL

The primary gesture feature, called FractalZoom was one touch for scrolling, and two fingers to pinch and zoom, technology that Bogue said he actually demoed to Apple in a private meeting in late 2003. The technology was shown off to what Bogue said was "maybe half a dozen" Apple hardware engineers. The meeting didn't go anywhere, though Bogue kept an e-mail thread between him and the company, which Samsung submitted as evidence.

DiamondTouch also had developed a follow-up technology called TableCloth, which Samsung showed off to once again take aim at Apple's bounce-back patent. TableCloth, which Bogue explained had been developed for Adobe's Flash platform, would bounce back images when they're pulled off screen.

Bogue argued that while this technology was only found on the company's multi-touch PCs, it was readily viewable by anyone who came into the MERL lobby. There the company kept a demo unit that was loaded with the latest software.

The two gesture patents are just part of Apple's patent offense against Samsung. As part of its suit against the South Korean technology giant, Apple is aiming one other of its patents for double tap screen navigation, as well as four design patents covering the iPhone and iPad.

The trial picks back up tomorrow and runs through the rest of the week. Both sides are expected to close up their closing arguments early next week.