Imagine That IP Law Blog

Earlier this week, the Federal Circuit issued an opinion in Sequoia Technology LLC v. Dell Inc. et al. that underscores the importance of intrinsic evidence when construing claim language in a District Court litigation. Of particular importance are the Court’s statements regarding the patent specification’s provision of an “express purpose of the invention” and a “preferred embodiment,” as well as the Court’s reliance on statements made by the Patent Owner in its pre-institution filings and on a document cited in an Information Disclosure Statement (IDS) during prosecution of the underlying Patent. In this case, the District Court used statements in the specification regarding the “express purpose” and “preferred embodiment” to narrow the meaning of certain claim terms. Additionally, while the two Inter Partes Reviews (IPRs) related to this case were ultimately not instituted, the District Court used statements made in the pre-institution filings, distinguishing two prior art references, to narrow the claim construction, leading to a finding of non-infringement, which the Federal Circuit affirmed.

In order to construe the meaning of “computer-readable recording medium,” “disk partition,” and “logical volume,” as recited in the claims of US6718436B2 at issue in Sequoia, the Federal Circuit looked in order of importance to (1) the language of the claims, (2) the specification, (3)  the prosecution history,  and finally (4) extrinsic evidence, such as expert testimony. This case can serve as a refresher as to how the Federal Circuit construes claims.

Language of the Claims
As the then Chief Judge Giles Rich of the Federal Circuit proclaimed, “the name of the game is the claim.” (In re Hiniker Co., 150 F.3d 1362, 1369 (Fed. Cir. 1998)). Likewise, in Sequoia, the Federal Circuit explained that when interpreting what the claims mean, the Court “start[s] with the claim language... and primarily, rel[ies] on intrinsic evidence like claim language when construing claim terms.” Sequoia Tech., LLC v. Dell, Inc., Nos. 2021-2263, 2021-2264, 2021-2265, 2021-2266, 2021-2267, 2023 U.S. App. LEXIS 8716, at *10 (Fed. Cir. Apr. 12, 2023) (internal citations omitted).

Specification
The next most important reference point for interpreting the claims is the specification. As the Court expressly states in  Sequoia, the “specification [is] highly relevant and the single best guide to the meaning of a disputed term” (Id. at *11)  (internal citations omitted).

For example, “a patentee is free to be his own lexicographer,” and in such cases, the interpretation of the claims “[is] bound by the patentee’s lexicography.” (Id. at *14) (internal citations omitted).   

In addition, when a patent specification explains the purpose of the invention, “a patent’s express purpose of the invention informs the proper construction of claim terms.”  (Id. at *18) (internal citations omitted). For example, in Sequoia, the Patent expressly states that the goal of the invention is to overcome the limitation of the conventional system like the “Baranovsky et al. patent [that] has problems of having too much metadata, delaying processing speed, delaying system-booting time, and using too much memory.” Therefore, the Court looked to the specification to determine how that goal of minimizing metadata was obtained and interpreted the claims in light of the described solution.

Similarly, when a specification identifies one or more preferred embodiments, the preferred embodiments may also inform the claim construction. For example, in Sequoia, the Court stated that “we also recognize that a claim construction excluding a preferred embodiment is rarely, if ever correct.” Id. at *19  (internal citations and markings omitted).

Prosecution History
Unlike before the Europe Patent Office, the prosecution history of a patent before the United States Patent and Trademark Office (USPTO)  may be limited by statements made during prosecution. For example, in Sequoia,  the Court expressly states that “prosecution history, which can inform how the inventor understood the invention and whether the inventor limited the invention during prosecution, thereby clarif[ies] the scope of a claim.” (Id. at *19).   Specifically, the Court looked to the prosecution history in Sequoia and observed that, in the course of prosecution, the Patentee distinguished the prior art based on what element is removed or added to form the logical volume. Therefore, the Court interpreted the claims in light of these statements.

In addition, the references cited by the Patentee in the course of prosecution can also inform the meaning of the claim terms. Specifically, when a patentee cites prior art, it may “have particular value as a guide to the proper construction of the term, because it may indicate . . . that the patentee intended to adopt that meaning.” (Id. at *23). For example, in Sequoia, the Patentee cited prior art papers by the Inventor, and the Court looked to these prior publications to attempt to construe the meaning of the claim term “use.” Therefore, the references cited in the course of prosecution in an Information Disclosure Statement (IDS) can also be utilized to inform the meaning of a claim term.

Of particular interest, the Court in Sequoia reminds us that the prosecution history of a patent is not limited to prosecution of the Patent before the United States Patent and Trademark Office (USPTO) and extends to post-grant proceedings before the USPTO. Specifically, the Court reiterated that “statements made by a patent owner during an IPR proceeding, whether before or after an institution decision, can be considered for claim construction.” (Id. at *19). Accordingly, any statements that are made by the Patentee, either in the course of prosecution or after grant, to the USPTO may be utilized to interpret the scope of the claim terms. 

Extrinsic Evidence
Extrinsic evidence,  such as expert testimony, is the weakest of the available reference points for properly construing claim terms. As the Court expressly stated in Sequoia, “[s]imply put, extrinsic evidence of what other inventors chose to do cannot surmount the intrinsic evidence of what the inventors chose here; context is key in claim construction.” (Id.  at *14).   The Court further cautioned that, when utilizing expert testimony, “a court should discount any expert testimony ‘that is clearly at odds with the claim construction mandated by . . . the written record of the patent.’” ( Id. at *14 ) (internal citations omitted). Therefore, although extrinsic evidence, such as expert testimony, can be utilized to inform the meaning of claim terms, the expert testimony is still bound by the intrinsic record of the Patent.

For Prosecutors
This case highlights the need for caution in drafting patent specifications, keeping in mind that the specification will be one of the most important documents a Court will use to construe the claim terms if the Patent is eventually litigated. If the Patent identifies an express purpose for the invention, the express purpose will very likely be used to interpret the scope of your claims. This can be a double-edged sword, as it may limit the claims’ enforceability against potential infringers, but it may also help to preserve validity against subsequent prior art-based challenges.

 Likewise, it is a best practice in patent drafting to specifically omit an identification of any embodiments as a preferred embodiment. Under the current US patent laws, it is enough to include the preferred embodiments without expressly identifying them in the specification. Sequoia clearly demonstrates that identifying a preferred embodiment can only be used against you later in Court.

Additionally, although it is common practice to routinely cite prior art in IDSs during patent prosecution, often without checking the content of the IDS to see whether it is actually relevant art or not, it may be beneficial to have a better understanding of the reference being cited. As the Court makes clear in Sequoia, the Court may use documents cited in an IDS, assuming that any definitions provided in those documents have been adopted by the Patentee.

For Patent Owners
In the Patent Owner’s Preliminary Response (POPR) or the Patent Owner’s Response (POR) filings in an Inter Partes Review (IPR), orienting an express purpose stated in the Patent with the prior art being cited in the Petition is often extremely helpful. For example, it can help overcome the prior art, as the express purpose may be completely different from what is in the prior art. This distinction will help inform not only the interpretation of the claim terms but will also support arguments related to the points of novelty or a motivation to combine the cited references. After all, the ultimate goal is to explain to the board how the claimed invention is both novel and inventive over the art cited by the Petitioner.

In addition, as is highlighted in Sequoia, statements made pre-institution can be used to interpret the claims in the corresponding District Court litigation and in subsequent IPRs. Accordingly, it is critical that IPR counsel work closely with litigation counsel to harmonize the construction of the claims. Similarly, with regard to any recitation of “preferred embodiments” in the specification, it is critical that any positions taken in the IPR are consistent with the positions taken in the district court litigation.

For Petitioners
The Petition needs to address any express purposes of the invention and/or preferred embodiments described in the Patent challenged in the IPR. Doing so may result in the desired claim construction in the District Court litigation, even if the IPR is ultimately not instituted. Additionally, while it is typically best to include an expert declaration with the Petition, complete reliance upon it may not be the best strategy. A stronger petition addresses intrinsic evidence of the Patent and utilizes the expert’s declaration to augment, but not to replace, the intrinsic evidence.