http://www.japaninc.net/print.php?articleID=653

according to there artical Yoshiro Nakamatsu does.

"He completed the project while at the University of Tokyo's Faculty of Engineering. The result, he says, was a "floppy media and drive" that could be read with magnetic and light sensors and for which he received a Japanese patent in 1952, 20 years before IBM got a US patent for a basic floppy design and 28 years before Sony and Philips Electronics introduced the compact disc in 1980. Big Blue will only say it owns the legal patent to the floppy and that it reached several nonexclusive patent agreements with NakaMats in the late 1970s to avoid conflicts."