Granted Patent
Utility
US 4,990,428 · App. 07/492,255
Photosensitive planographic printing plate
Inventors:
Shigeki Shimizu, Hiroshi Ide
Patented Case
View Patent ↗
Granted: Feb 5, 1991
Filed: Mar 12, 1990
Inventors
Shigeki Shimizu
Hiroshi Ide
Assignee (at issue)
Mitsubishi Kasei Corporation
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.