Williamson Aftermath: A Big Shift In Functional Claiming

October 31, 2016

Andrew (A.J.) Tibbetts
(as published in IP Law360)

The Federal Circuit’s 2015 en banc decision in Williamson v. Citrix Online[1] has triggered a significant shift in the interpretation of “functional”[2] claims in district courts and before the U.S. Patent and Trademark Office’s Patent Trial and Appeal Board. By one estimate, more than 50 percent[3] of issued patents will be affected by this shift, which could leave patent claims greatly narrowed in scope or even invalid. It is therefore critical for both patent owners and potential defendants to understand how Williamson is presenting new strategy options and undermining old ones.

We have been tracking Williamson’s impact since our 2015 Law360 Expert Analysis article “3 Functional Claiming Questions To Address Post-Williamson,” and have seen that Williamson has exposed a swath of issued patents to narrower claim interpretations or invalidity. Post-Williamson, many more claims are now open to interpretation under the particularized approach to construction of “means-plus-function” claim elements. This shift is significant. If construed as means-plus-function, a claim element is narrowly interpreted to cover only the corresponding “structure” (and reasonable equivalents) explicitly described in the patent’s text and drawings for performing the recited function. Where no examples of structure are given, the claim will be found invalid.

This shift in interpretation may particularly impact the electrical, computer, and software industries, where the relatively common form of claiming a “computer,” “circuit” or “processor” “for performing” or “configured to perform” a given function is now more likely to be construed as a means-plus-function limitation. Until Williamson, Federal Circuit precedent[4] provided a “strong” presumption against construing a claim element as being in means-plus-function format where there was a “structural” term like a “circuit” or “processor” used together with the function, rather than the classic “means for” recitation. This precedent gave patent owners near certainty that by using terms such as “computer for,” “circuit for” or “processor for,” instead of “means for,” functionally claimed computer inventions would enjoy broader scope than those subject to means-plus-function construction.

Williamson weakened this presumption and, by doing so, upset the established understanding of variants on functional claiming language. Because a majority[5] of patents issued over the last 20 years include such variants, few patent owners will be unaffected by this ongoing change in the patent landscape.

Williamson’s Impact

District court and PTAB cases following Williamson demonstrate a substantial shift in functional claim interpretation. In particular, terms like “processor” and “circuitry” that have long been assumed to be well outside the bounds of means-plus-function interpretation have, since Williamson, been cast into doubt. Multiple courts have interpreted under the means-plus-function framework language reciting a “processor” that is programmed to perform a function.[6] One PTAB case has even found a “circuitry” limitation to be means-plus-function language.[7] This is a stark shift from years of pre-Williamson claim construction.

Courts’ rationale in these cases proceeds in two steps. First, while a term like “processor” is structural by itself, the courts find the term is not structural when recited as a “processor programmed to” perform a recited function, because the processor cannot natively perform that function and instead would require a complex programming not recited in the claim. Second, the courts typically look at the recited detail of the function performed. If a claim simply recites a goal or end result of a function, rather than a way of achieving that function (e.g., a specific algorithm), it is more likely the claim element will be construed as a means-plus-function claim. Using this latter test, one court found a “processor” to be a means-plus-function term, but found a “module” not to be, based primarily on the algorithm incorporated into the claim regarding the function to be performed by the module.[8]

There are also signs that Williamson may upend traditional understandings of interpretation of method claims. Until recently, any argument for a “step-plus-function” interpretation (the method-claim equivalent of means-plus-function claims) of claim language would likely have been rejected out of hand, in view of Federal Circuit precedent. Since Williamson, we have seen more arguments that claims should be construed as step-plus-function. Although these arguments have been unsuccessful so far,[9] the fact that such efforts have been made is a reminder of the changing landscape and a trend to watch.

The PTAB has been in some ways leading the charge on a broader application of means-plus-function rules. Even pre-Williamson, there was a flurry of cases in which the PTAB found “processor” limitations to be means-plus-function terms.[10] More recently, in appeals from examiner rejections, the Board has been aggressively applying the means-plus-function rules, upholding examiner decisions to apply means-plus-function framework to claim language in spite of applicant arguments against it[11] and even imposing means-plus-function interpretation where an examiner did not, suggesting or outright issuing new rejections.[12]

The PTAB’s aggressive application of means-plus-function has even impacted America Invents Act trials. In one case, the PTAB declined institution of an inter partes review based on its conclusion that a claim element should be construed under the means-plus-function rules, even where neither of the parties requested that interpretation.[13]

Building New Strategies and Casting Off the Old

Patent owners and potential defendants should ensure their counsel fully understands the significant practical impact of this ongoing shift. On the patent owner side, failing to properly account for Williamson’s impact may lead to patents that are severely constrained in scope or potentially even invalid, or at best much more costly and complex to enforce. For defendants, understanding Williamson may reveal new strategy options for cost-effective resolutions to litigations or early settlements. There may be an outsized impact on the electrical, computer and software industries, due to the prevalence of functional language in patent claims to those technologies.

The Williamson decision’s aftermath presents new challenges for patent owners. It will be important to account for the new trend when drafting new applications, both in choosing particular language for claims and in structuring specifications. Given the new uncertainty over old standby practices like reciting a “processor programmed to,” and until that uncertainty is resolved, it may be important to consider alternatives that may fare differently under evolving claim construction principles. In choosing strategies for drafting applications, including on the precise language to use, it may be more important than ever to weigh the particular facts of the technology at issue and the commercial context of the products a patent is to support, rather than simply recycling the same options between applications. Linking claim language describing a function to corresponding descriptions in the specification, or including more detail in claims, may also be vital, as both may help avoid the pitfalls of means-plus-function interpretation. Of course, it will be important to balance claim coverage against the commercial needs of the patent owner, to ensure the claims still have valuable scope.

Patent owners may see some upside, though. It may be a valuable strategy at times to leverage the Williamson decision to achieve a narrower interpretation of a claim, for example to help that claim avoid prior art located by a defendant or IPR petitioner.

For defendants, one strategy is clear: a means-plus-function interpretation can offer an early out at the Markman stage. A narrow reading when the claim is limited to the specification’s disclosure can be used to develop non-infringement positions. And if there is no corresponding structure in the specification, a means-plus-function construction can be a complete victory. Of course, this is not without trade-offs. Especially when pushing for invalidity, defendants risk getting halfway there — limiting the claim to the disclosed embodiment but not invalidating the claim. This can pose issues if there is a strong infringement read, but the prior art performs the same functions using different “means” of doing so.

[1] Williamson v. Citrix Online LLC, 792 F.3d 1339 (Fed. Cir. 2015) (en banc).

[2] A “functional” claim recites the invention in terms of what it does, rather than how it does it.

[3] Dennis Crouch, Functional Claim Language in Issued Patents, January 23, 2014, http://patentlyo.com/patent/2014/01/functional-language-patents.html.

[4] Lighting World Inc. v. Birchwood Lighting Inc., 382 F.3d 1354, 1358 (Fed. Cir. 2004).

[5] Dennis Crouch, Functional Claim Language in Issued Patents, January 23, 2014, http://patentlyo.com/patent/2014/01/functional-language-patents.html.

[6] Velocity Patent LLC v. Mercedes-Benz USA, LLC, 2016 WL 5234110, *5-7 (E.D.Ill, Sep. 21, 2016); St. Isidore Research, LLC v. Comerica Inc., 2016 WL 4988246, at *14-15 (E.D.Tex, Sep. 18, 2016); GoDaddy.com, LLC v. RPost Communications Ltd., 2016 WL 212676, *31 (D. Ariz. Jan. 19, 2016).

[7] Ex Parte Eun Young Hwang, Appeal 2014-005927, (PTAB, Aug. 8, 2016).

[8] St. Isidore Research, LLC v. Comerica Inc., 2016 WL 4988246, at *14-15 (E.D.Tex, Sep. 18, 2016).

[9] In re: Neurografix ('360) Patent Litigation, 2016 WL 4425712 (Mass., Aug. 19, 2016).

[10] Ex Parte Smith, 2012-7631 (PTAB Mar. 14, 2013); Ex Parte Lakkala, 2011-1526 (PTAB Mar. 13, 2013); Ex Parte Erol, 2011-1143 (PTAB Mar. 13, 2013).

[11] See, e.g., Ex parte William B. Sebastian et al., Appeal 2013-006223 (PTAB, Jul. 30, 2015).

[12] See, e.g., Ex parte Atsushi Shimizu et al., Appeal 2013-005039 (PTAB, Aug. 3, 2015).

[13] HP Inc., v. Memjet Tech. Ltd, IPR2016–00356, (PTAB, June 16, 2016).