SAN JOSE, Calif.--Apple Inc.'s (AAPL) patent case against Samsung Electronics Co. (SSNHY, 005930.SE) moved closer to its final stages Friday, as the two tech titans presented their last witnesses in the high-stakes patent trial.

Apple and Samsung spent Friday bringing up a mix of people to discuss technical details of the patents Samsung claims are being violated and to rebut witness testimony.

Though Apple started the legal battle with its initial lawsuit, Samsung fired back by accusing Apple of infringing on its patents, such as those for handling photographs in an email and one regarding wireless transmissions.

Apple called to the stand Hyong Kim and Edward Knightly, both engineering and technology professors, who discussed Samsung's patents, describing how the patents could even be invalid in some cases and how Apple's own devices don't infringe on them in others.

One flashpoint in the case has erupted outside the courtroom, in an ongoing debate within the technology industry about patents that are part of agreed-upon standards, such as 3G wireless technology.