The United States patent laws set forth a number ways that an inventor can loose all
rights to obtain a patent on his or her invention. Unfortunately, some of the ways in
which the right to obtain a patent can be lost are not intuitively obvious. Listed below are
the most common ways that patent rights can be lost:
a. Someone with an Earlier Date of Invention. Even if the applicant
is the first to file a patent application on an invention, if someone else establishes that they
have an earlier date of invention (as set forth in the Date of Invention section below), then
they will prevail and obtain the patent. Inability to establish an actual reduction to
practice date or diligence between that date and the date of conception can result in the
loss of patent rights.
b. Sale or Attempt to Sale. Patent rights are lost if the inventor or
someone on his or her behalf sells or attempts to sell the invention in the United States
more than one (1) year prior to filing the patent application. A sale between related
companies, even if secret, can start the clock. An assignment of patent rights does not
constitute a sale.
c. Public Use. Patent rights are lost if the inventor or someone on his or
her behalf publicly uses the invention in the United States more than one (1) year prior to
the filing of the patent application. It is not necessary that the use be observable, only
that it be public (i.e., use of process in a factory can be public use even if used in the
normal course of business and not purposefully shown). There is an experimental use
exception for an invention that is only used in public as part of its development (i.e., prior
to its reduction to practice). Reliance on the experimental use exception is very fact
dependant and can be risky.
d. Patented or Printed Publication. An inventor loses his or her
United States patent rights if the invention was the subject of a patent or disclosed in a
printed publication anywhere in the world more than one (1) year prior to the United
States patent filing date. In order to be a bar to patentability, the patent or printed
publication must disclose the invention, be accessible to the public and be properly
cataloged and indexed.
e. Abandonment. Abandonment of patent rights results from doing
nothing to protect or develop your invention for a long period of time. This often arises
when someone has attempted to keep the invention secret for too long a period of time
and now wants to patent it. Abandonment can also occur through violation of a national
security secrecy order.