A patent allows an inventor to exclude others from making, using, selling, offering for sale, or importing the patented invention without the inventor’s permission for a limited period of time. Patent rights are granted by federal law, which also provides that an inventor whose patent is infringed may seek a remedy in court as one might for other wrongs. There are several defenses to patent infringement that may be asserted by one who is sued for patent infringement. One defense that not only will negate infringement liability but will also destroy the validity of a patent is inequitable conduct on the part of the inventor in procuring the patent.

The most fundamental requirement for an invention to be patented is that is must be new. If an invention has already been patented, it cannot be patented again. In addition, if descriptions of the invention exist in literature or the invention has been made or used for a certain amount of time before a patent application is sought, the invention will not be considered new and is not eligible for a patent. The body of information that might reveal that an invention is not new is called the “prior art.” The failure of an inventor to disclose the existence of prior art that might affect the patentability of the invention or the submission of false material in a patent application for the purposes of deception are forms of inequitable conduct that may render a patent ineffective. Inequitable conduct amounts to fraud committed upon the United States Patent and Trademark Office (USPTO), which reviews patent applications and issues patents. Included in the type of information that must be revealed to the USPTO is whether a claim of inequitable conduct has been raised against the patent applicant in a prior patent infringement action.

In order for an alleged infringer to prevail in an infringement lawsuit based on the defense of inequitable conduct, the infringer must prove that the patent owner acted intentionally in omitting information or providing false information about the patent and that the false or omitted information would have affected the patent examiner’s assessment as to whether the invention was patentable. Both of these elements of the inequitable conduct defense must be proven by clear and convincing evidence. If that burden of proof is carried by the infringer, the patent will be unenforceable, and an infringement suit will fail.

Copyright 2012 LexisNexis, a division of Reed Elsevier Inc.