Nvidia has sued Samsung and Qualcomm for allegedly infringing seven of its patents related to GPUs, and is trying to block the sale of some Samsung products in the U.S. The lawsuits open a new and unexpected front in the smartphone patent wars, which have already led to numerous court battles. In a blog post Thursday, Nvidia called it an "important day" for the company and said they are the first patent lawsuits it has initiated in its 21-year history.