Granted Patent
Utility
US 4,234,671 · App. 06/021,800
Color diffusion transfer dye mordant
Inventors:
Hideaki Iwama, Mikio Koyama, Masao Asano, Yasuo Tsuda
Patented Case
View Patent ↗
Granted: Nov 18, 1980
Filed: Mar 19, 1979
Inventors
Hideaki Iwama
Mikio Koyama
Masao Asano
Yasuo Tsuda
Assignee (at issue)
Konishiroku Photo Industry Co., 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.