Yoshiro Nakamatsu
Among Nakamatsu's early inventions is the Shoyu Churu Churu, a siphon pump used in the home to move soy sauce from large containers to smaller vessels for cooking and serving. His patented inventions include:
Based upon a patent issued in 1952, Nakamatsu claims to have invented the first floppy disk well before IBM's floppy disk patent was filed in 1969. However, what Nakamatsu patented in 1952 was a paper for optical sound player. In contrast to a floppy disk, this Nakamatsu patent discloses the use of printed paper for storage instead of the magnetic material of a floppy disk. It is not rewritable and lacks most elements of the IBM floppy disk patent. Since the paper was 'floppy' material, he claims he had invented the floppy disk (sometimes he uses the phrase "floppy media"); however, it should be noted that flexible magnetic recording media was well known prior to 1952, in tape and wire recording.
Floppy disk
A small notch disk identifies that it is writable, detected by a mechanical switch or phototransistor above it; if it is not present, the disk can be written; in the 8-inch disk the notch is covered to enable writing while in the -inch disk the notch is open to enable writing. Tape may be used over the notch to change the mode of the disk. Punch devices were sold to convert read-only disks to writable ones and enable writing on the unused side of single sided disks; such modified disks became known as flippy disks.