We’re starting to see a theme develop here. Now that it’s Samsung’s (005930) turn to present its case in the San Jose, California patent trial that regularly has the tech media abuzz, the company is taking an interesting approach. Rather than start out by arguing that its various Android smartphones and tablets do not copy Apple’s (AAPL) designs or infringe on its patents, Samsung is arguing that Apple’s IP is invalid to begin with. On Monday, Samsung argued that Apple’s pinch-to-zoom patent was stolen from Mitsubishi’s old Diamond Touch and on Tuesday evening, Samsung made a similar argument regarding the design of Apple’s iPad.