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.
History of science and technology in Japan
Sony introduced the 3½-inch floppy disk format, called the micro floppy disk. The first commercial micro floppy disk drive was the Sony OA-D30V, released in 1981. Sony's initial 3½-inch floppy disk format was dual-sided and held 875 KB of data storage.