For the 21st consecutive year, U.S. technology giant IBM led the nation in obtaining patents, a survey by a patent-tracking firm has found. IBM was granted 6,809 patents in 2013, outpacing second-place Samsung's 4,675, the survey by research firm IFI Claims Patent Services showed. More than 600 of IBM's patents originated at the company's Research Triangle Park campus near Raleigh, N.C. "Our software team, in particular, is doing a lot of patent work there," IBM spokesman Michael Rowinski told The (Raleigh) News & Observer. Only three U.S. companies -- IBM, Microsoft and Qualcomm -- made the top 10 on the patent awards list. The other seven -- including giants Canon, Sony, Panasonic and Toshiba -- have headquarters in South Korea, Japan and Taiwan.