View source for Electric Storage Battery Co. v. Shimadzu, 307 U.S. 5 (1939) (Robins)

circuit court ruled patents valid and infringed.

Supreme Court granted centari.

Case in question has 3 patents by a Japanese citizen.  The petitioner filed for the 3 patents on separate dates:
 No. 1,584,149 on January 30, 1922; (fine lead powder.)
 No. 1,584,150 on July 14, 1923;(process to make fine lead powder)
 No. 1,896,020 on April 27, 1926(machine to manufacture lead oxides)

Shimadzu had invented these in Japan and claimed that although they had been used in Japan, they were not on sale. the date of filing in Japan for the entire process was determined to be June of 1921.

The law requires that Shimadzu file in the US within 2 years of the invention.  Shimadzu claims that he had abandoned the older inventions and did not claim them in previous patents he filed.  Therefore the discrepancies in dates.

The Supreme Court agreed that he did not try to hide the true methods in his patents, but because they had been in use in Japan, all of the inventions are subject to the 2 year requirement.  Therefore 150 and 020 are invalid and a new trial will be given to determine if 149 was infringed.