Case No. 2012-1255 (Prost, Moore, O’Malley) (nonprecedential)
Breadth in claims can be achieved in a number of ways, both with the claim language itself and external tactics like claim differentiation or redefining a claim term more broadly in the specification. When trying to narrow a claim to avoid prior art, however, the primary approach is to simply focus on changing the claim language. In re Sutton includes a short discussion reminding that all sources of broadening, both within and outside of the specific claim language, should be taken into account when trying to narrow around the prior art. In Sutton, claim differentiation supported a broad construction of several claims in prosecution.
Sutton filed application 12/190,101 on a vinyl coating that did not require a plasticizer to preserve color and flexibility. All claims in the application were eventually rejected as obvious over a four-reference combination, which the Board twice affirmed. The structure and relationship among the claims was important, as paraphrased in the opinion:
7. A vinyl film subject to outdoor weathering, comprising a fluorescent dye and a terpolymer of ethylene—vinyl acetate—vinyl chloride that imparts color stability and flexibility to the film.
8. The film of claim 7, further comprising a plasticizer.
9. The film of claim 7, further comprising polyvinyl chloride.
30. The film of claim 7, wherein the film does not include a plasticizer.
The applicant argued before the Board and Federal Circuit that claims 7 and 9 could not cover a composition including a plasticizer under claim differentiation, because claim 8 explicitly recites the use of a plasticizer. Such a construction might not have been obvious, because the primary reference taught some embodiments that included a plasticizer.
This argument actually hurt the applicant before the court. The panel stated that, given the “comprising” transition, the addition of the plasticizer element in claim 8 did not exclude it from claims 7 and 9 under claim differentiation:
Claims 7 and 9 both use the transitional term “comprising” prior to reciting the required elements of the claimed composition. While the recited elements in claims 7 and 9 are necessary to form the claimed composition, by using the open-ended phrase “comprising,” the claims may include other unclaimed elements, such as a plasticizer.
. . .Sutton could have limited the scope of claims 7 and 9 by adding an explicit “no plasticizer” limitation, much like he did in claim 30. For whatever reason, Sutton did not choose to impose such a limitation on these claims.
In addition, claim 8 requires a generic plasticizer and claims 14 and 19 require different forms of plasticizers. These claims are narrower than claim 7 because they each require a particular type of plasticizer, while claims 7 and 9 simply permit the use of one.
Rather, claim differentiation worked the exact opposite way sought by the applicant here – because claim 30 did literally and only exclude plasticizers, claim 7 must permit plasticizers in its formulation:
Contrary to Sutton’s position, moreover, a straight-forward application of the doctrine of claim differentiation actually confirms, rather than undermines, this reading of the claims. Claim 30, which expressly excludes a plasticizer, would be superfluous were claims 7 and 9 read to exclude plasticizers.
The court noted that, in the alternative, claim 30 was found to be obvious over embodiments that did explicitly exclude plasticizers. So it would not have likely mattered if the claims had been limited as sought by the applicant. The court also refuted haphazard arguments by the applicant that the references were not combinable or would not have possessed the recited “color stability” would not have inherently existed in the combined references. The court accepted the Examiner’s and Board’s findings as supported by substantial evidence that there was motivation to combine all asserted references and that the references taught the use of a known color stabilizer.
Lessons: Claim differentiation is a valid basis to support a broad claim construction in prosecution, and an Examiner might fairly point to narrowing in dependent claims to interpret an independent claim term beyond the subject matter of the dependent claim. So watch out for dependent claims that undermine arguments against overbroad interpretations of independent claims in prosecution. If you have an independent claim reciting “element A” and a dependent claim narrowing element A to “A1,” an argument that the independent claim must be construed as limited to A1 to overcome the prior art disclosing “A2” probably won’t work. It’s especially not going to work in a situation like in Sutton where a different dependent claim narrowed element A to “A2.” Instead, either amend your claim to capture the dependent claim having the unmet species or argue that dependent claim.
Now Marine Polymer comes to an essentially opposite conclusion on claim differentiation. There the en banc plurality narrowly construed independent claims to wholly exclude some dependent claims in prosecution while explicitly rejecting claim differentiation. But I read that case as dependent on very strong limiting language in the specification that forced the independent claim to be narrowly construed in prosecution despite claim differentiation. In such a situation, it’s probably best to cancel the dependent claims and argue the spec as controlling the construction if you need the limited specification construction for prior art avoidance purposes.
Comment: Sutton’s application and the Board opinions are not published (or, at least, I can’t find them on the Board’s terrible awful opinion search page). I’ve always wondered about the requirement that unpublished applications be held in confidence versus publication of tribunal opinions on unpublished applications. The confidentiality is often defeated, at least in substantive part, by the tribunal opinion, as would appear to be the case in Sutton. Is there authority that an applicant waives the confidentiality requirement by proceeding to appeal? I’m guess there is; can anyone help me out in the comments? Lastly, the court suggests the arguments on appeal here were not very well-presented or persuasive. Why no Rule 36 affirmance here for an unpublished application in a nonprecedential case?