In a landmark decision May 28 by the U.S. Supreme Court on Festo USA vs. SMC, the high court reversed the U.S. Court of Appeals for the Federal Circuit (CAFC) ruling that a patentee is precluded by the prosecution history estoppel (A bar preventing one from making an allegation or a denial that contradicts what one has previously stated as the truth) from leveraging on the application of doctrine of equivalents to a claim limitation that was used to assert the patentability of a claim during the prosecution of a patent. The eagerly awaited decision by the legal and technology communities will have wide-sweeping implications from patent prosecution, patent litigation, to patent licensing.

In other words, if the CAFC’s decision was not reversed, an inventor, who narrowed some aspects of a patent application during prosecuting the patent, would not have protection on whatever elements that were changed.

The U.S. Supreme Court’s unanimously reversed the CAFC’s decision and said that the decision went too far and that only Congress can make such broad changes to patent law. The case is sent back to the CAFC for review.

Implications:

Patent holders should be glad that the U.S. Supreme Court had reversed the CAFC’s decision that made proving patent infringement difficult. However, the reversal is not an outright victory as the Supreme Court decision held that ‘prosecution history estoppel may apply to any claim amendment made to satisfy the Patent Acts requirements, not just to amendments made to avoid the prior art, but estoppel need not bar suit against every equivalent to the amended claim element.” 

Thus, implying that even though amending claims during prosecution does not automatically preclude application of doctrine of equivalents, the courts are allowed to use their discretion in examining patent application changes and decide how they affect claims of patent infringement. However, the CAFC’s previous ruling may be an indication of the courts’ unwillingness in applying the doctrine of equivalents to grant broad patenting rights. 

To maintain protection of patent rights, inventors and companies should explore different strategies in their original application filing, such as doing a thorough prior art search so that differentiation from prior art is presented in the application, filing both broad and narrow claims, and filing different embodiment claims. Thus, limiting the need to amend the application as much as possible to ensure that history estoppel is not used against the patent holder during infringement litigation.

Fernandez & Associates LLP

High-Technology lawyers specializing in early-stage electronics, communications, software, and biotechnology companies based in Menlo Park, CA.  In addition, the Firm provides patent strategy advisory services, specifically, in providing management teams of emerging technology ventures with practical and effective strategies to building valuable Intellectual Property portfolios, as well as minimizing legal risk of infringing IPRs of other entities.