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
Because the sectors have constant angular size, the 512 bytes in each sector are compressed more near the disk's center. A more space-efficient technique would be to increase the number of sectors per track toward the outer edge of the disk, from 18 to 30 for instance, thereby keeping nearly constant the amount of physical disk space used for storing each sector; an example is zone bit recording. Apple implemented this in early Macintosh computers by spinning the disk more slowly when the head was at the edge, while maintaining the data rate, allowing 400 KB of storage per side and an extra 80 KB on a double-sided disk. This higher capacity came with a disadvantage: the format used a unique drive mechanism and control circuitry, meaning that Mac disks could not be read on other computers. Apple eventually reverted to constant angular velocity on HD floppy disks with their later machines, still unique to Apple as they supported the older variable-speed formats.