by Dennis Crouch
Rain Computing, Inc. v. Samsung Electronics (Fed. Cir. 2021)
Rain and Samsung agree that this case comes down to claim construction. And, as typical, the patentee is attempting to thread the needle with a construction that is broad enough to be infringed, but narrow and specific enough to avoid invalidation. The district court construed one term narrowly — resulting in no infringement. On appeal, the Federal Circuit focused on a separate term — and found its indefiniteness rendered the claim invalid.
Rain’s US Patent 9,805,349 covers a method for delivering apps via a computer network using a webstore and server authentication. The claim requires “a user identification module configured to control access of said one or more software application packages.” If you have been following patent claim construction over the past decade: You know that the focus here will be whether this “module” limitation invokes 35 U.S.C. § 112 ¶ 6 as a means-plus-function term. And, if so, is it indefinite for failing to provide sufficient structural support in the specification.
Normally, patent claims are expected to spell out the actual structure of the invention — not just its function. However, § 112 ¶ 6 (now renamed § 112(f)) allows a patentee to avoid adding those specifics in combination claims by including an element “as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof.” The statute goes on to include an important caveat, the element “shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.” The statute does not spell-out what happens when the specification lacks any corresponding structure — but the courts have filled the gap. A means-plus-function claim that lacks corresponding structural disclosure in the specification is deemed invalid as indefinite.
Means-plus-function claiming is fools gold — especially for anyone with a thin disclosure. The claims appear broad, but are narrowly interpreted and regularly invalidated. For years, patentees have moved away from using the term “MEANS” and replaced it with some other generalized word such as “MODULE” as used in this case. By skirting the MPF trap, these newly styled claims were more broadly interpreted and rarely invalidated as indefinite. However, that approach was collapsed by the case of Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015). In Williamson, the Federal Circuit held that claim terms that “fails to recite sufficiently definite structure or else recites function without reciting sufficient structure for performing that function” will also be interpreted as a means-plus-function term. Although the burden on invoking 112(f) is still on the patent-challenger, Williamson eliminated the heavy presumption that it doesn’t apply.
The further trick with Williamson: (a) If a particular term – such as “module” is structurally defined within the specification then it will typically not be interpreted as means-plus-function because it was particularly defined by the applicant. (b) On the other hand, if the term is not structurally defined in the specification, then it will invoke 112(f) and also be found indefinite for lack of structural support.
Here, the court first noted that the word “MODULE” “is a well-known nonce word that can operate as a substitute for ‘means’.” The Williamson case itself focused on the word module and found that it did not indicate any “structure.” The court drew the same conclusion in Rain Computing— finding that the claimed “user identification module” has no commonly understood structure and the specification included no structural disclosure.
Here, the specification does not impart any structural significance to the term; in fact, it does not even mention a “user identification module.”
Slip Op. So, we fall into the category (b) from above: Nonce word without structural support → therefore → Invoke 112(f) and invalidate. The court writes:
Nothing in the claim language or the written description provides an algorithm to achieve the “control access” function of the “user identification module.” When asked at oral argument to identify an algorithm in the written description, Rain could not do so. Without an algorithm to achieve the “control access” function, we hold the term “user identification module” lacks sufficient structure and renders the claims indefinite.
Slip Op. Thus, the claim is indefinite. This rendered the separate non-infringement related claim construction moot.
During prosecution the patent examiner had expressly stated that the limitation “does not invoke 112, 6th paragraph, or 112(f).” However, the examiner’s somewhat cryptic reasoning was that a 112(f) means limitation cannot exist within a method claim. On appeal, the Federal Circuit noted the examiner’s error: “Applicants are free to invoke § 112 ¶ 6 for a claim term nested in a method claim.”
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Note: In Synchronoss Techs., Inc. v. Dropbox, Inc., 2019-2196, 2021 WL 520047 (Fed. Cir. Feb. 12, 2021), the Federal Circuit encountered a claim a quite similar limitation: “user identifier module.” In that case the court also found that the term invoked 112(f) but was indefinite from lack of structural support.
(Fed Cir Clerks – note that FN 1 in Rain Computing does not accurately reflect the language of the claims in Synchronoss).
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Above, I noted the draw of means-plus-function claim language for “thin disclosures.” In this case, the disclosure was actually quite extensive, but the patentee appears to have wanted to shift the scope of coverage away from the original focus of the invention disclosure. This patent is one of nine US patent applications all within the same direct family and relying on the same original disclosure.