Part of the complexity inherent in a patent infringement suit is that infringement (or noninfringement) and most defenses challenging the validity of a patent proceed on a claim-by-claim basis. This forces both the patentee and the alleged infringer to carefully consider how their proposed construction of terms can affect each individual claim of the patent for purposes of both infringement and invalidity.
But one affirmative defense sidesteps this complexity and promises a clean victory for an alleged infringer: inequitable conduct. In its simplest form, inequitable conduct is a straightforward application of equitable principles: A person found to have committed some form of wrongful conduct related to the issuance of the patent is barred from enforcing the patent. For example, if a patent applicant engages in deception by manufacturing false evidence, or suppressing material evidence during the prosecution process, the applicant may be found to have committed inequitable conduct and be barred from enforcing the patent.
