Granted Patent
Utility
US 5,496,993 · App. 08/095,193
Optical pickup device with wedge shaped and concave lens for correcting a coma and astigmatism
Inventor:
Ikuo Kasuga
Patented Case
View Patent ↗
Granted: Mar 5, 1996
Filed: Jul 23, 1993
Inventor
Ikuo Kasuga
Assignee (at issue)
Kabushiki Kaisha Sankyo Seiki Seisakusho
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.