Tackling Unreasonably Broad Claim Constructions: A Little-Known Tool To Help Accused Infringers Keep Patent Holders Honest

October 9, 2013

(as published in IP Law360)

It has long been the case that statements made to the U.S. Patent and Trademark Office (USPTO) during patent prosecution can limit the breadth of an issued patent’s claims. It would be quite difficult, in fact, to find a patent litigator who has not quoted the U.S. Supreme Court’s circa 1886 statement that patent claims are not to be treated like a “nose of wax,” twisting them one way to avoid prior art, when before the USPTO, and then twisting them in another direction to capture accused infringers, when before a district court.

Now, thanks to a little-known provision buried deep in the America Invents Act (AIA), the converse is also true. That is, a patentee’s statements to a district court advocating a broad claim scope to ensnare accused infringers can now be used to justify equally broad claim interpretations for the purpose of assessing patentability in USPTO post-grant proceedings. In effect, the new provision (specifically, 35 U.S.C. § 301(a)(2)) establishes consequences for patent holders who advocate unreasonably broad constructions before a district court.

What Has Changed?

Under the new AIA provision, anyone is permitted to submit court documents to the USPTO that reveal a patent owner’s position on the scope of a particular patent. The USPTO may then consider those statements in determining a patent claim’s proper meaning during an ex parte reexamination, inter partes review, or post-grant review proceeding.

As the USPTO is generally required to give claim terms their “broadest reasonable construction” during post-grant proceedings, patent owners who find themselves back before the USPTO during or after district court litigation will, in effect, be stuck with any unduly broad constructions they advocated before the district court, unless they are prepared to admit that the arguments they made to a federal judge were “unreasonable.” Accused infringers have thus been provided a valuable tool to turn the tables on overreaching patent owners by urging the USPTO to hold patent owners to their overly-broad constructions when re-assessing patentability.

Who Do You Think You’re Talking To?

While claim construction briefs are primarily addressed to the federal judge hearing the case, they now have a potential secondary audience. Statements made by the patent holder concerning the scope of claims in such briefs – as well as responsive briefs by the accused infringer – can now come before a patent examiner in the course of a reexamination or other post-grant review process.

Indeed, the new provision mandates that an accused infringer (or anyone else) who cites a patent owner’s statement to the USPTO must also provide all documents, pleadings, or evidence from the proceeding in which the statement was filed that addresses the written statement. Accordingly, patent litigators need to be mindful that everything presented to the district court during claim construction might also ultimately be considered by the USPTO.

Is Raising a Post-Grant Challenge a Good Idea?

U.S. patent law presumes an issued patent is valid, and any challenger to that patent must present “clear and convincing” evidence to the contrary in district court. This is not true for post-grant proceedings, during which patent claims are not presumed valid and no heightened standard of proof is required to show such claims are unpatentable.

In fact, the USPTO does not even purport to evaluate the “validity” of challenged patent claims during post-grant proceedings. Instead, it merely considers whether such claims are “patentable” and only requires a mere “preponderance of the evidence” to find claims unpatentable.

Furthermore, the claim construction methodology employed by federal courts is different than that used by the USPTO. Under the Federal Circuit’s en banc decision in Phillips v. AWH Corp., district courts will give disputed terms their “correct” construction, while the USPTO will give claim terms their “broadest reasonable construction.” Ambiguous claim language may be construed more broadly by the USPTO than by a district court, potentially allowing the USPTO to read that language on a piece of prior art in a way the district court would not.

Certain situations may allow a challenger to take these different approaches into consideration when determining whether to institute a patentability challenge in the USPTO. For example, given the lesser burden of proof required by the USPTO, as well as the potentially broader claim construction during USPTO proceedings, a challenger having a relatively strong invalidity position (based on prior art patents and printed publications) may very well prefer to invoke a post-grant proceeding, putting the patentability decision in the hands of a technically trained examiner rather than a jury of laypeople with little or no technical training. On the flip side, a challenger having a relatively weak invalidity position may prefer to roll the dice with a jury.

The chart below highlights some of the important differences between the standards and approaches of a district court validity challenge and a post-grant proceeding.

District court validity challenge vs. post-grant proceeding


Post-grant challenges provide a potentially powerful weapon for launching counterattacks against patent holders who advocate overly-broad claim constructions that seemingly read on prior art patents or printed publications.

Whether it makes sense to take advantage of a patent holder’s overreaching claim construction positions by instituting a post-grant challenge must be assessed on a case-by-case basis. However, taking such a step should, at the very least, be considered whenever a patent owner attempts to stretch patent claims too far before the court.