Granted Patent
Utility
US 6,728,034 · App. 09/593,239
Diffractive optical element that polarizes light and an optical pickup using the same
Inventors:
Hideyuki Nakanishi, Shoichi Takasuka, Shinichi Ijima, Akio Yoshikawa, Teruhiro Shiono
Patented Case
View Patent ↗
Granted: Apr 27, 2004
Filed: Jun 14, 2000
Inventors
Hideyuki Nakanishi
Shoichi Takasuka
Shinichi Ijima
Akio Yoshikawa
Teruhiro Shiono
Assignee (at issue)
SUMITOMO ELECTRIC INDUSTRIES, LTD.
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.