Yoshiro Nakamatsu
Nakamatsu claims IBM reached licensing agreements with him in the late 1970s. He also claims to have licensed his floppy disk to IBM in 1979, but that the details are "confidential". An IBM spokesman, Mac Jeffery, confirmed that the company did license some of his patents, but claimed they were not for the floppy disk, which he claimed IBM invented on its own. Another IBM spokesman, Brian Doyle, said they licensed 14 patents from Nakamatsu, but also claimed that they do not have anything to do with the floppy disk.
Shugart Associates
Shugart Associates (later Shugart Corporation) was a computer peripheral manufacturer that dominated the floppy disk drive market in the late 1970s and is famous for introducing the 5-inch minifloppy floppy disk drive. In 1979 it was one of the first companies to introduce a hard disk drive form factor compatible with a floppy disk drive, the SA1000 form factor compatible with the 8-inch FDD form factor.