A charge of inequitable conduct usually arises as a defense to a charge of patent infringement. If inequitable conduct is found, the patent is rendered unenforceable. Other undesirable consequences may result, including liability for attorney's fees and antitrust damages, and suspension or exclusion from practice before the Patent Office. Accordingly, attorneys and patent agents should disclose all material information of which they are aware. Most findings of inequitable conduct are based on failure to disclose material information or misrepresentation of material information to the Patent Office.
Intent is also a critical element.
For a court to invalidate a patent due to inequitable conduct, it must find an intent to deceive the Patent Office. If both materiality and intent are established, levels of materiality and intent are then balanced to determine whether inequitable conduct exists. For example, failure to disclose prior art can be a material omission even if the patent would still have issued if the prior art had been disclosed. Other types of omissions can also be material, such as failure to disclose the best mode of an invention and failure to reveal unfavorable test results. Testing which occurs more than one year prior to the date of filing the patent application can be material, even if the test is arguably for experimental use and thus an exception to the public use bar.