Granted Patent
Utility
US 5,617,393 · App. 08/365,169
Optical disk having an erased-state indicator and optical disk apparatus for reducing frequency of disk erasing operation
Inventors:
Satoshi Itami, Masaru Nakahara, Masahiro Nakada, Hiroshi Suzuki, Kenichi Utsumi
Patented Case
View Patent ↗
Granted: Apr 1, 1997
Filed: Dec 28, 1994
Inventors
Satoshi Itami
Masaru Nakahara
Masahiro Nakada
Hiroshi Suzuki
Kenichi Utsumi
Assignee (at issue)
Fujitsu Limited
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.