Guest Post by Jason J. Du Mont, Microsoft IP Fellow at the Indiana University Maurer School of Law and Mark D. Janis, Robert A. Lucas Chair of Law at the Indiana University Maurer School of Law.

In Pacific Coast Marine Windshields Ltd. v. Malibu Boats, the Federal Circuit addressed a question of first impression: whether an applicant’s actions taken during prosecution of a design patent should be available for use when determining the design patent’s scope in subsequent litigation.  The court’s answer was yes.  While the answer may be unremarkable, the court’s unusual journey from question to answer raises broader questions about the wisdom of absorbing utility patent law’s judicially-derived doctrines into design patent law.

The applicant had filed a design patent application claiming “an ornamental design of a marine windshield with a frame, a tapered corner post with vent holes and without said vent holes, and with a hatch and without said hatch, as shown and described.”  The application included eleven drawings showing windshields with various numbers of vent holes, with and without hatches. During prosecution, the examiner imposed a restriction requirement and identified five patentably distinct groups in the application: windshields having “(1) four circular holes and a hatch; (2) four circular or square holes and no hatch; (3) no holes and a hatch; (4) no holes and no hatch; and (5) two oval or rectangular holes and a hatch” (internal citation omitted):

The applicant elected group one without traverse (which showed four circular holes and a hatch), deleted the figures not associated with this embodiment, and eventually rewrote the claim in a more conventional form, claiming “[t]he ornamental design for a marine windshield, as shown and described.”  The application issued as D555,070.  The applicant later filed a divisional directed to group three, which issued as D569,782, but there were apparently no further divisionals.

Pacific Coast subsequently asserted the ‘070 patent against Malibu Boats, which was producing a windshield having three square vent holes, as depicted below:  

Malibu Boats moved for summary judgment of non-infringement based on prosecution history estoppel.  The district court granted the motion and Pacific Coast appealed. 

No Distinct Doctrine of Equivalents for Design Patents

Prosecution history estoppel is a limitation on the doctrine of equivalents, so before it reached the district court’s prosecution history estoppel analysis, the Federal Circuit first had to determine whether the design patent law should recognize a doctrine of equivalents.  The court concluded that for design patents, literal infringement and infringement under the doctrine of equivalents are “intertwined,” pointing to the statute (35 U.S.C. § 289, which provides a remedy when another party “applies the patented design, or any colorable imitation thereof, to any article of manufacture for the purpose of sale” (emphasis added)), and the Gorham v. White case (which holds that infringement is based on substantial similarity). 

The court could have been more forthcoming as to what it means for the two infringement standards to be intertwined, but the key takeaway is clear: the design patent infringement analysis isn’t bifurcated into a literal infringement prong requiring identicality and an equivalency prong.  It relies on a test of substantial similarity based on the design’s overall impression. The court’s analysis signals that there’s no longer a need to speak of a distinct “equivalents” concept in design patent law; concepts of equivalency are built into the substantial similarity test.

 So Why Incorporate Prosecution History Estoppel?

Having recognized that design patent law includes no distinct doctrine of equivalents, the Federal Circuit could have declared that design patent law need not incorporate the utility patent law’s prosecution history estoppel jurisprudence.   The court could have formulated a prosecution history-based limiting doctrine that was customized to connect to design patent law’s “intertwined” infringement standard.  Or, the court could have even analogized to prosecution disclaimer, a simpler concept which limits literal claim scope and avoids entanglement with the presumptions and rebuttal routes of a post-Festo prosecution history estoppel doctrine.  See, e.g., Trading Techs. Intern., Inc. v. Open E Cry, LLC,  728 F.3d 1309 (Fed. Cir. 2013) (discussing the distinction).

Instead, the court stated that the “principles” of prosecution history estoppel applied to design patents, and resolved those principles into a three-step test: “(1) whether there was a surrender; (2) whether it was for reasons of patentability; and (3) whether the accused design is within the scope of the surrender.” It then relied on Festo and other utility patent cases in applying its test, concluding that “no presumption of prosecution history estoppel could arise” because there wasn’t any showing that the third part of the test was met.

Whatever this presumption is, it surely isn’t the Festo presumption.  Festo holds that a narrowing amendment that is substantially related to patentability triggers a presumption that the applicant surrendered all territory between the original and amended claim scope with regards to the claim limitation in question.  See, e.g., Duramed Pharma. v. Paddock Labs., Inc., 644 F.3d 1376 (Fed. Cir. 2011). There isn’t any third step calling for scrutiny of the accused device.   That inquiry would only be relevant to determining the scope of the estoppel—and that only comes into issue once it’s determined that the presumption of estoppel applies, and that the presumption hasn’t been rebutted. 

The court’s approach is likely to lead to confusion in design patent cases about how much utility patent doctrine really has been borrowed.  (It may also create some confusion in utility patent cases if it’s invoked there.  Doing so would be erroneous, in our view.)  This illustrates why it’s not always so easy, or desirable, to fling utility patent doctrine into design patent law.  The court could have avoided all of these doctrinal convolutions by steering clear of prosecution history estoppel jurisprudence and either drawing on simpler analogies or developing a test specific to design patents.

Applying the Court’s Three-Step Test

The Federal Circuit’s application of its three-step test further illustrates why borrowing from prosecution history estoppel doctrine may have been a bad idea.  In addition to diverging from the Festo presumption, the court’s rhetoric slips towards the element-by-element conceptions of equivalency and estoppel that govern in utility patent law, and away from conceptions of the design’s overall impression that design patent law mandates.

The court concluded that steps one and two of its test were met.  As for step (1), the applicant had deleted drawings directed to the patently distinct two-hole and no-hole embodiments, resulting in a surrender of scope, according to the court; and, as for step (2), deletions made in response to a restriction requirement were made for purposes of patentability and thus could trigger estoppel.  As the court pointed out, however, this latter point hasn’t been resolved in utility patent law.

Nevertheless, the court decided that step (3) (whether the accused design was within the scope of the surrender) wasn’t met, and that was enough for a reversal.  The defendant had chosen not to argue that the accused three-hole design was within the scope of the patentee’s non-elected designs.  Instead, the defendant asserted that because the patentee had elected designs having four holes (in the ‘070 patent-in-suit) and zero holes (in the ‘782 divisional), the patentee had surrendered any designs having a number of holes between zero and four.  The court was not persuaded, reasoning that the notion of surrendering an entire range “does not work in the context of design patents where ranges are not claimed, but rather individual designs.  Claiming different designs does not necessarily suggest that the territory between those designs is also claimed.”  These are crucial observations for limiting the impact of prosecution history estoppel, especially since the court didn’t address any other way of rebutting this presumption.

But the court left unaddressed the key question about applying step (3): what is the standard for determining whether an accused design falls within the scope of the surrender?  Some raw notion of “colorable imitation”?  A fully elaborated substantial similarity analysis in view of the prior art as per Egyptian Goddess?  Something else?

Moreover, by framing its analysis of the designs at issue by reference to the number of holes, the court encourages a mode of analysis that rests on individual design features, rather than the design’s overall impression.   There’s a deep disconnect here between utility and design patent law.  Equivalency (and, correspondingly, prosecution history estoppel) in utility patent law is to be applied on an element-by-element basis, but that doesn’t translate neatly to design patent law.   Here, where the embodiments differed by discrete, readily-identifiable features (such as the number of holes or hatches), perhaps the presence or absence of the features dictate one’s conclusions about the design’s overall impression.  We think this will not be so easy in most cases involving visually-complex designs.

More to Come …

The prospect that restriction and election practice will give rise to estoppel in design matters has significant practical consequences.  First, the implementation of the Hague will unquestionably lead to an influx of international applications that often contain plural embodiments—either explicitly allowed or because they are filtered from registration systems.  When coupled with distinctions in the determination of scope, between offices, the USPTO can expect to receive higher volumes of applications that may necessitate restrictions.  Second, the Federal Circuit’s In re Owens decision, and the USPTO’s apparent turn towards a more aggressive application of the written description requirement in design cases, may force design patent applicants to submit applications including large sets of drawings that depict numerous implementations of a design concept.  To the extent that these implementations are deemed patentably distinct embodiments, many applicants will find themselves facing restriction requirements.

That leads to the case’s key practical point:  if courts choose to apply Pacific Marine’s estoppel rule aggressively, practitioners may need to advise their clients to expect to file more divisionals—and, consequently, face higher prosecution costs.