The Invention Process
The United States: A First
to Invent Country
Since the U.S. is a first to invent country, a patent is granted to
the person who can prove that he or she was the first to invent. This
differs significantly from most countries where the patent is awarded
to the first person who files a patent application. When a person can
prove that he or she was the first to invent,
priority of invention
Priority of invention is awarded to the one who can
prove that he or she was the first to invent. The inventor
with priority of invention is granted the patent.
Although the U.S. does not have a first to file system, having
the earliest possible filing date is still important. The advantage to
this is realized when two or more parties claim the same invention.
When this event occurs, an interference is declared.
An interference is an administrative proceeding that
takes place in the U.S.P.T.O. During this proceeding, the
Board of Patent Appeals and Interferences must deter-
mine who was the first to invent. The one who can prove
priority of invention is entitled to the patent.
The party having the earliest possible filing date is awarded senior
party status. This status places the burden of providing evidence of
an earlier date of invention on the other party, or the junior party. In
order to win the interference, the inventor must show the earliest
date of conception and reduction to practice. In addition, the inven-
tor may need to provide evidence that he or she was diligent in re-
ducing the invention to practice and subsequently preparing and ill-
The U.S.: A First to Invent Country
ing a patent application in the U.S.P.T.O. There are three ways in
which a party may win an interference:
(1) by being the first to conceive and the first to reduce to
(2) by being the first to conceive and the last to reduce to prac-
tice, coupled with diligence; and
(3) by being second to conceive but first to reduce to practice
where the other party was
diligent in reducing the invention to
Figure 3.1 and the following example demonstrates the third
Chet conceived of a new watch mechanism on Feb-
ruary 3, 1995. However, due to financial constraints
and personal obligations he was not able to begin
working on the invention until December I, 1995.
From December I, 1995 until February 3, 1996, Chet
worked continuously on the new watch mechanism.
On February 3, 1996, he had completed testing on the
mechanism. On March 3, 1996, Chet filed his patent
application in the U.S.P.T.O., claiming the mechanism.
Fred conceived of a new watch mechanism that was
similar to Chet's, on July 3, 1995. Fred was so excited
about his idea that he immediately went to work on a
prototype. By November 1, 1995, Fred had completed
testing on the mechanism. On January 3, 1996, Fred
filed his patent application in the U.S.P.T.O., claiming