Expert Searcher Check Permits Estoppel for Unknown References

by Dennis Crouch

Ironburg Inventions Ltd. v. Valve Corp., — F.4th —, 21-2296 (Fed. Cir. Apr. 3, 2023)

The latest determination in Ironburg Innovations Ltd. v. Valve Corp. has important implications for post-IPR estoppel underneath 35 U.S.C. § 315(e)(2). On this case, the Federal Circuit adopted a “expert searcher” commonplace to find out whether or not grounds not raised within the unique IPR “fairly” may have been raised on the time. The court docket additionally addressed the burden of proof in estoppel instances, with the Federal Circuit holding that it lies with the get together in search of the estoppel — a ruling that aligns with conventional follow and the perfect studying of the statute.  These requirements and procedures are essential as a result of they supply readability on the scope of estoppel and assist stabilize the legislation, notably given diverging district court docket rulings on these points. One attention-grabbing facet of Ironburg is the break up 2-1 determination on indefiniteness, which I’ll deal with in a separate submit.

Earlier than delving into the case, it’s also price noting that the difficulty of estoppel and its nuances are presently pending earlier than the U.S. Supreme Court docket in Apple v. CalTech. In Apple, the Federal Circuit broadly utilized the estoppel doctrine, and the Supreme Court docket is now contemplating whether or not to grant certiorari.

Lack of Data and a Expert Searcher Check: After being sued for infringement, Valve challenged Ironburg’s sport controller patent by way of inter partes evaluation (IPR).  That administrative motion ended with a closing written determination favoring the patentee — i.e., Valve misplaced.  Again in district court docket, Valve tried to problem the validity once more – this time primarily based upon non-petitioned grounds that it gleaned from a competitor’s IPR petition towards the identical Ironburg patent. The district court docket barred Valve’s defenses as estopped underneath § 315(e)(2)  after concluding Valve “fairly may have raised” these grounds in its unique IPR. Valve argued that it had no information of these references on the time of its IPR petition and subsequently couldn’t have included them as problem grounds. Nonetheless, each the district court docket and the Federal Circuit held that lack of awareness isn’t an entire excuse.  Quite, in instances the place the IPR challenger lacks information of the prior artwork the suitable check for estoppel is what “a talented searcher conducting a diligent search fairly may have been anticipated to find.”

Burden Shifting: One query on attraction is which get together has the burden of proving that the bottom fairly may have been raised within the IPR.  The district court docket (seemingly) positioned the burden on the patent challenger to show that it couldn’t have fairly raised the difficulty. In some methods, that burden is smart as a result of the IPR challenger is in the perfect place to grasp and show its stage of data  (or lack thereof) on the time.  On attraction, nonetheless, the Federal Circuit flipped that ruling — holding as a substitute that the burden lies with the get together in search of the estoppel to show estoppel.  For my part, this end result higher aligns with each custom and the studying of the statute.

Digging a bit into the weeds: the district court docket’s holding principally concludes that Valve fairly ought to have been capable of finding the references because the different IPR challenger discovered them.  On attraction, the appellate court docket discovered some defective logic — an inherent and unproven assumption made by the district court docket was that the opposite IPR challenger used solely affordable diligence to seek out the artwork. If, however, it took “extraordinary measures” to seek out the references and assemble the problem floor, then no estoppel ought to apply.

The patentee had received a $4 million judgment on the unique trial, however on remand, the district court docket might want to rethink its estoppel determination. If the result’s no-estoppel, Valve will get a 3rd likelihood at invalidating the patent. This case underscores the significance of conducting a diligent search to determine all potential grounds for invalidity after which placing the perfect grounds ahead within the IPR petition.