By Ned LaDuca,* Matt Modderman, Matt Johnson –
A Delegated Rehearing Panel (“DRP”) recently modified the PTAB’s construction of the claim term “workload” and remanded, giving Mercedes-Benz USA, LLC (“Petitioner”) another opportunity to challenge a processor patent. Mercedes-Benz USA, LLC v. Daedalus Prime LLC, IPR2023-01343, Paper 27 at 8 (PTAB Apr. 24, 2025) (“Decision”).
Petitioner sought inter partes review of select claims from U.S. Patent No. 8,898,494 (the “’494 Patent”), which describes a method and system for “efficiently balancing performance and power between processing elements based on measured workloads.” Decision at 4. The PTAB instituted review and ultimately issued a Final Written Decision (“FWD”) finding that Petitioner failed to prove the challenged claims were unpatentable. Id. at 3. Petitioner then requested Director Review of the PTAB’s FWD. Id. The Acting Director delegated Director Review to the DRP to answer two questions: (1) whether the PTAB erred in construing the claim term “workload,” and (2) whether the PTAB erred in finding that U.S. Patent No. 7,263,457 (“White”) does not teach such a workload in the context of the challenged claims. Id. at 2.
On the first issue, the PTAB sided with the Patent Owner and construed workload as “an amount of activity over a quantum or period of time.” Id. at 11 (quoting FWD at 15). The PTAB relied on the Patent Owner’s declarant, Petitioner’s declarant’s deposition testimony, and the ’494 Patent specification. Id. The PTAB also noted that Petitioner did “not dispute this proposed construction in its Reply.” Decision at 11. On the second issue, in view of its construction of “workload,” the PTAB determined that White does not teach or suggest the challenged claims’ subject matter. Id. at 12.
In support of a broader construction on review, Petitioner argued that the ’494 Patent “confirms workload is not limited to a measurement of amounts of activity over time, but can be reflected by any measurement or metric related to the ‘use’ of a component.” Id. at 13 (quoting Director Review Request at 9). Petitioner also denied that it did not dispute the Patent Owner’s proposed construction in its Reply. Id. As to whether White teaches the disputed workload claim limitations, Petitioner asserted that “while frequency and voltage may not expressly be ‘an amount of activity over a quantum or period of time,’ they nonetheless reflect a metric of the ‘use’ of a component.” Id. (quoting Director Review Request at 12). Thus, according to Petitioner, “White’s disclosure of monitoring frequency and voltage meet the ’494 Patent’s express definition of what constitutes a determination of ‘workload.’” Id. (quoting Director Review Request at 13).
In response, Patent Owner argued that methods for determining or measuring workload are irrelevant to the definition of workload. Decision at 13–14. Patent Owner also asserted that its declarant’s testimony regarding White was sufficient support for the PTAB’s decision, whereas Petitioner’s declarant did “not provide any evidentiary support for his testimony.” Id. at 14.
The DRP addressed the PTAB’s construction of “workload” first. The DRP found that the ’494 Patent “does not explicitly define the term ‘workload’ but provides several examples of measuring a workload.” Id. at 15. First, one passage in the ’494 Patent provides an “amount of activity (e.g., amount of active cycles) over a quantum or period of time” as an example of measuring workload. Id. Second, another passage explains a workload can be determined using “any other metric for determining use of a processing element.” Id. The DRP found that these passages and further examples within the ’494 Patent reveal a broader meaning of “workload” as a claim term.
In addition, the DRP found that although “Petitioner did not propose an express construction of ‘workload’” in its petition, Petitioner’s arguments were premised on such an interpretation of the claim term. Decision at 17. Specifically, in its reply, “Petitioner asserted that determining a workload encompasses any metric for determining use of a processing element, citing the broad description in the ’494 patent quoted above.” Id. “Petitioner raised this argument in the context of arguing why, in its view, White teaches the claimed determining a workload.” Id.
Thus, the DRP agreed with Petitioner that the construction of workload is broader than the PTAB determined. Rather than workload meaning “an amount of activity over a quantum or period of time,” id. at 11, the DRP broadened this definition with two words: “an amount of activity or use over a quantum period of time,” id. at 15 (emphasis added). The DRP otherwise declined as unsupported by the ’494 Patent Petitioner’s assertion “that the construction should be even broader to encompass any metric ‘related to the “use” of a component[.]’” Id.
With respect to whether White teaches the workload limitations of the ’494 Patent and renders the challenged claims unpatentable, the DRP remanded the issue back to the PTAB. Because of the newly modified construction of “workload,” the DRP remanded “out of an abundance of caution[.]” Id. at 19.
Takeaway: Arguments that a prior art reference discloses particular subject matter can be construed as advocating for (or against) a certain claim construction. Petitioners and patent owners alike should carefully consider the implications of their invalidity positions. And where a specific claim construction is necessary to the success of a position, litigants should state their support or opposition to that proposed construction explicitly.
* Ned is a summer associate in Jones Day’s Cleveland Office.
Matthew Johnson
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