Claim Interpretation Urged by Patent Owner in District Court Infringement Litigation May Be Relied on by Petitioner in IPR Challenge

By: Tammy Dunn

In Western Digital Corporation v. SPEX Technologies, Inc. (“Western Digital IPR”), the Patent Trial and Appeal Board (“PTAB”) recently allowed a petitioner to use a patent owner’s claim construction positions taken in district court infringement litigation in an IPR petition, even though the petitioner explicitly disagreed with those positions in district court.

At the time the petitioner filed its IPR petition, the parties had already taken certain claim construction positions and obtained tentative claim construction rulings in the concurrent district court litigation.  It is not uncommon for a patent owner to assert broad claim interpretation in the litigation to increase the likelihood of proving infringement, while proposing narrower claim constructions in the PTAB in defense of patentability.  In this case, the petitioner, instead of proposing specific claim constructions, stated that the petition was “based on the claim constructions urged by Patent Owner in the Litigation, or as the parties agreed.”  In the past, the PTAB has routinely ignored the claim constructions asserted in concurrent court proceedings as being irrelevant, among other reasons.

In this instance, the patent owner urged the PTAB to deny institution of IPR trial, arguing that the petitioner failed to sufficiently identify its own claim construction positions.  According to the patent owner, the petitioner should have stated in its petition that the petitioner believed the patent owner’s constructions to be correct, particularly because the petitioner had explicitly argued in district court that some of these constructions were incorrect.

The PTAB disagreed with the patent owner and concluded that IPR rules do not require a petitioner “to express agreement regarding correctness of its proffered claim constructions or to take ownership of those constructions.”  Instead, a petitioner need only identify claim constructions it proposes as the basis for requesting review of the challenged claims.  Petitioner’s statement in its petition that it was “based on the claim constructions urged by Patent Owner” was sufficient.   This is a significant change from prior PTAB practice.

The PTAB was not troubled by the fact that the petitioner was taking contradictory claim construction positions in its IPR position and the district court.  According to the PTAB, even though the petitioner explicitly disagreed with certain of the patent owner’s proposed constructions in the district court litigation, because the petitioner did not disagree with those positions within the IPR petition itself, the petitioner was free to adopt the patent owner’s district court claim construction positions for the purposes of the IPR.

Concurrent proceedings have always presented a risk that statements made by a party in one proceeding might be used against that party in another proceeding.  Here, however, the petitioner was able to use the patent owner’s own claim construction statements from the district court litigation against the patent owner, while the patent owner was not similarly able to use the petitioner’s own statements made in the district court litigation against the petitioner.  The patent owner was put in the difficult position of having to choose between, on the one hand, arguing to the PTAB that its own claim constructions proposed in the infringement litigation were too broad, or else saying nothing.  Though the decision does not explicitly say one way or another, it appears this patent owner chose to say nothing about the correctness/incorrectness of its own claim construction positions and instead focused on the inconsistency of the petitioner relying on positions in the IPR that the petitioner had previously argued were incorrect.

Because this decision was not precedential, other PTAB panels may or may not decide similar cases in the same way.  Therefore, as a practical matter, petitioners with specific claim construction positions that are important for the IPR should still specifically articulate them within an IPR petition.  If a petitioner chooses to rely on the patent owner’s statements from district court in an IPR, the petitioner should merely adopt those positions without commentary and not express any disagreement with those positions within the IPR petition.  Meanwhile, patent owners could try including statements in their district court claim construction materials that expressly limit the application of their proposed constructions to district court proceedings only and not IPRs.  A future PTAB panel may or may not heed such limitations, however.  Therefore, the most prudent course of action for patent owners is to make sure the positions they take in district court infringement actions are ones they can live within IPR proceedings.

For more information about IPR practice, please contact Tammy Dunn at