Materials from a presentation by Austen Zuege and Jonathan Bench about patent assignments and rights of priority, including presentation slides and an on-demand video recording, are available here:
Have an invention you would like to patent? Have a brand you would like to register as a trademark? Concerned about infringing someone else’s intellectual property? Is someone else infringing your IP? Need representation in an IP dispute? Austen is a patent attorney / trademark attorney who can help. These and other IP issues are his area of expertise. Contact Austen today to discuss.
Abstract: This article provides critical analysis of the doctrine of assignor estoppel for patent assignments following the Supreme Court’s Minerva v. Hologic decision, which limited the situations in which the doctrine is available to those that involve a “contradiction” by the assignor that violate norms of “fair dealing”. An overview of the likely abrogation of prior Federal Circuit cases is provided. Although, as explained, there are significant policy disputes that underlie the doctrine that have not been definitively resolved, which will undoubtedly be the subject of dispute in future cases. Also addressed, and questioned, are corollaries and related Federal Circuit precedents involving privity, the effect of purported assignments of future inventions and the role of claim construction to preserve validity defenses. For the latter, an “assignor estoppel donut” is conceptualized to highlight the multiple boundaries involved, of which Minerva’s holding addressed only one. Lastly, an analysis of pragmatic assignment scenarios and potential areas of dispute around them is set forth, in order to inform both assignment drafting and negotiation, on the one hand, and legal disputes over existing assignments, on the other.
Austen Zuege is an attorney at law and registered U.S. patent attorney in Minneapolis whose practice encompasses patents, trademarks, copyrights, domain name cybersquatting, IP agreements and licensing, freedom-to-operate studies, client counseling, and IP litigation. If you have patent, trademark, or other IP issues, he can help.
What are the minimum requirements to establish enhanced damages for patent infringement after the passage of the America Invents Act (AIA) and the U.S. Supreme Court’s decision in Halo, and what evidence can be presented on this point? Post-Halo cases reveal areas of ambiguity and dispute. Some dispute involves willfulness theories falling close to the line between reckless conduct sufficient to establish willfulness and merely negligent conduct that is not willful. But a lingering ambiguity is how 35 U.S.C. § 298 may exclude from willful patent infringement certain conduct that might be considered reckless—and thus willful—in other areas of tort law. For whatever reason, § 298 has received little attention or treatment, which has even led to decisions contrary to that statutory provision.
A Brief History of Willfulness
Let us begin with some context for how willfulness has evolved in patent law.[i] Damages enhancement is governed by 35 U.S.C. § 284, even though the term “willful” does not explicitly appear there. In the early 1980s, the Federal Circuit established an affirmative duty of due care and an adverse inference of willfulness if the accused infringer did not both obtain advice of counsel and waive privilege to present an advice of counsel defense.[ii] Decades later, the Federal Circuit abolished the adverse inference in Knorr-Bremse.[iii] Then it abolished the affirmative duty of due care in Seagate, substituting a two-prong willfulness analysis requiring “objective recklessness” as a prerequisite.[iv] In the aftermath of those cases, the AIA introduced § 298, which prohibits use of the failure to obtain advice of counsel or make an advice of counsel defense to establish willfulness (or inducement).[v]
In 2016, the Supreme Court in Halo threw out the “objective recklessness” prerequisite, finding its “inelastic constraints” insufficient to allow courts to punish “the full range of culpable behavior.”[vi] The Court held that “culpability is generally measured against the knowledge of the actor at the time of the challenged conduct.”[vii] Therefore, “[t]he subjective willfulness of a patent infringer, intentional or knowing, may warrant enhanced damages, without regard to whether his infringement was objectively reckless.”[viii] The Court discussed how reckless conduct supports punitive damages where willful intent is required while merely negligent conduct does not, clarifying that “a person is reckless if he acts ‘knowing or having reason to know of facts which would lead a reasonable man to realize’ his actions are unreasonably risky.”[ix] The abrogated “objective recklessness” threshold had allowed classically reckless conduct to be exonerated by after-the-fact rationalizations, which meant that some reckless conduct was inappropriately shielded from punitive enhanced damages.[x]
Later Federal Circuit cases have interpreted Halo as abrogating the “objective recklessness” requirement in a relatively narrow way but leaving intact much other pre-Halo case law,[xi] which presents challenges for anyone trying to parse out the way older cases may have been abrogated only in part but are potentially still controlling as to other aspects. The Federal Circuit has maintained that “willfulness” is a question of intent involving the accused infringer’s state of mind that is for the finder of fact (jury) to decide,[xii] and knowledge of the asserted patent is a prerequisite to a finding of willfulness.[xiii] After willfulness is established, the question of enhancement of damages is then a question for the court (rather than jury) to decide[xiv]—though a willfulness verdict does not automatically entitle the patentee to enhanced damages.[xv] But a court’s discretionary moral judgment regarding enhancement does not depend on any preceding factual finding of a particular state of mind or level of intent of the infringer.[xvi]
District court decisions post-Halo have begun to explore the minimum requirements to plead and then introduce evidence of willfulness, though the Federal Circuit has not yet reached some of the new theories definitively. These various new theories address what it means to subjectively “have reason to know” that accused conduct presents an unreasonable risk of patent infringement in the absence of direct evidence that the accused party actually knew about the patent and that there was a high probability its conduct infringed, as well as the effect of the accused taking affirmative steps to avoid learning of such facts.[xvii]
New Theories of Willful Infringement
First, a number of district courts have found “willful blindness” to be an acceptable theory of willful patent infringement. Motiva from the Eastern District of Texas is perhaps the most widely known of these cases, holding that “[s]ince the Supreme Court has explained that willful blindness is a substitute for actual knowledge in the context of infringement, it follows that willful blindness is also a substitute for actual knowledge with respect to willful infringement.”[xviii] Willful blindness has two basic requirements: (1) the accused must subjectively believe that there is a high probability that a fact exists, and (2) the accused must take deliberate actions to avoid learning of that fact; these two requirements mean willful blindness has a limited scope that surpasses recklessness and negligence.[xix] To avoid dismissal, patentees must make “plausible” willfulness allegations regarding both requirements for willful blindness.[xx]
What has generated much discussion about willfulness theories relying on willful blindness is the role of “no patent review” corporate policies that (at least on paper) bar employees from reviewing competitor patents.[xxi] Yet the mere existence of such a “no patent review” policy is not per se sufficient to plead willful blindness for willful infringement unless there is also a plausible allegation that the accused party subjectively believed a high probability of patent infringement existed.[xxii] In practical terms, this means there must be something more than simply a blanket corporate policy that applies to any and all (competitor) patents and that “something more” must plausibly suggest a culpable state of mind with regard to infringement of the asserted patent.
Second, some courts have addressed other theories—distinct from “willful blindness”—that an accused infringer should have reasonably known about the asserted patent. For example, district courts are divided about whether actual knowledge of an unasserted family-related patent coupled with an allegation that the accused should have investigated that patent family to discover the asserted patent—such as a broader continuation or broadening reissue—is sufficient to support willfulness.[xxiii] At times, these other theories appear uncomfortably close to the old, abrogated affirmative duty of due care.[xxiv] These other theories seem less stringent and more expansive than willful blindness, partly because they fall close to the boundary between negligence and recklessness but also because decisions on these theories often contain little or no discussion of why the accused had reason to know that there was infringement of a later-issued patent and not merely reason to know that the later-asserted patent existed.[xxv]
Statutory Limits on Evidence of Willfulness Under § 298
But what about § 298? A curious feature of many post-Halo willfulness cases is how little that section introduced by the AIA is discussed or even cited by courts when dealing with issues to which it directly relates, namely the relevance of evidence under the second Read factor: “whether the infringer . . . investigated the scope of the patent and formed a good-faith belief that it was invalid or that it was not infringed.”[xxvi] This is most troubling when courts proffer reasoning based on case law that was abrogated by § 298 (if not also by Seagate). Section 298 states:
“The failure of an infringer to obtain the advice of counsel with respect to any allegedly infringed patent, or the failure of the infringer to present such advice to the court or jury, may not be used to prove that the accused infringer willfully infringed the patent or that the infringer intended to induce infringement of the patent.”[xxvii]
There can be no question that § 298 excludes certain evidence from use to prove willfulness, including (1) the failure to consult an attorney and (2) the decision to maintain privilege over advice received from counsel. Yet an asymmetrical framework remains: the accused infringer is still free to obtain a legal opinion and later voluntarily present an advice of counsel defense based on that legal advice,[xxviii] but a “decision not to seek an advice-of-counsel defense is legally irrelevant under 35 U.S.C. § 298.”[xxix]
The key effect of § 298’s framework has to be that “having reason to know” for a (recklessness) willfulness theory must be limited to what the accused infringer reasonably should have known at the time without the assistance of counsel. The scope of the accused party’s (subjective) knowledge of the intricacies of patent law will vary considerably, though. For instance, lay parties might reasonably believe that broader later-issuing patents or reissues are not likely or that something like prosecution laches would apply to them.[xxx] This subjective knowledge may be difficult to even infer from circumstantial evidence in situations in which the accused did obtain advice of counsel but chooses not to waive privilege and not to make an advice of counsel defense based on that advice. And mere speculation on this point is generally inadequate. Moreover, as one district court held, attempts to suggest what the accused knew based on privileged communications not in evidence may be improper as a “disguised” attempt to circumvent the limits set forth in § 298.[xxxi] In a somewhat counterintuitive way, § 298 provides two distinct incentives to obtain advice of counsel because an accused party can either waive privilege in such advice and present an advice of counsel defense or maintain privilege and later potentially shield certain state of mind inquiries or inferences implicating that (maintained) privilege.[xxxii]
Does a Duty of Due Care Still Exist? And Does It Matter?
Seagate abrogated the affirmative duty of due care; but when Halo later abrogated the “objective recklessness” standard, a question arose as to the impact of Halo’s abrogation of the abrogation of the duty of due care.[xxxiii] The Federal Circuit has not explicitly weighed in on this point, and no Federal Circuit case since Halo mentions the term “duty of due care” at all. On the one hand, § 298 makes the existence or nonexistence of a judicially created duty of due care less important. But a real question remains about how patentee use of the second Read factor against an accused infringer may now be abrogated in whole or part. Can an accused party’s failure to conduct a nonlegal investigation of some sort regarding an asserted patent be used to establish willfulness today?
Worth mentioning at the outset is the Federal Circuit’s Broadcom case regarding induced infringement. There, despite the abolishment of the duty of due care, “[b]ecause opinion-of-counsel evidence, along with other factors, may reflect whether the accused infringer ‘knew or should have known’ that its actions would cause another to directly infringe, . . . such evidence remains relevant.”[xxxiv] This is not at all straightforward. At first blush, failure to meet an abolished/nonexistent duty of due care hardly seems relevant, logically if not legally. But in any event, the passage of § 298 abrogated precedent like Broadcom with regard to failure to obtain advice of counsel (or to present such a defense).[xxxv] But if the duty of due care only ever pertained to advice of counsel, then its abrogation (by statute or case law) might have left intact some separate due inquiry obligation under the second Read factor.[xxxvi]
Tending to complicate matters here are cases reaching conclusions plainly contrary to § 298, or reaching conclusions as to the boundaries and implications of that section without meaningful explanation. For instance, one district court ruled that “failure to produce . . . an opinion for trial can be considered as a factor in the jury’s determination of willfulness.”[xxxvii] Astoundingly, that court discussed old cases without any reference to their abrogation, and its ruling ended up permitting use of statutorily barred evidence for willfulness.[xxxviii] Moreover, a nonprecedential Federal Circuit decision discussed the second Read factor and found that a lack of investigation of asserted patents provided some evidence of willfulness, reaching that conclusion without discussing legal relevance limits under § 298.[xxxix]
Justice Breyer’s concurrence in Halo suggested that a nonlawyer analysis of an asserted patent might be enough to show a lack of willfulness,[xl] though the majority opinion was silent about that scenario. But that very issue came up in a district court case that held a willfulness verdict to be supported by evidence that “years of lucrative infringing sales [occurred] after failing to respond to the . . . licensing letter with a minimally adequate analysis of whether a license would be necessary,” which the court said was not prohibited by § 298 because the jury was instructed to disregard such matters, although the accused did try to present evidence of a nonlawyer invalidity analysis that the court excluded at trial.[xli] This illustrates the problem of courts too often suggesting what is in effect an adverse inference in jury instructions and then trying to immediately unring the bell by stating that no adverse inference of willfulness is permitted.
Yet a contradiction often remains. A more defensible formulation is that a jury’s inferences of knowledge of the asserted patent and of infringement can support a willfulness finding in the absence of countervailing evidence. That is, an accused infringer simply runs a greater risk of a willfulness finding if no advice of counsel defense or the like is pursued to rebut willfulness allegations because a jury can properly infer minimally sufficient knowledge and intent even in the absence of direct evidence on those points, and this does not require going so far as to assign any probative value to a failure to act. There is an important difference between willfulness being inferred from unrebutted circumstantial evidence and the failure to act (e.g., to investigate or seek legal advice) itself being treated as positive evidence of willfulness.
It is fair to distinguish the possibility of the accused making a nonlawyer analysis or inquiry defense to a charge of willfulness from an affirmative duty to do so. On its face, § 298 bars patentees from arguing about failures to obtain or present “advice of counsel” evidence.[xlii] But nothing in the literal text of § 298 bars evidence of a failure to conduct a lay investigation of an affirmative claim of infringement. Yet excluding evidence of nonlawyer investigations or analyses by the accused runs against Justice Breyer’s Halo concurrence, if not also the implicit framework of § 298.
In these senses, the question of what evidence is relevant and what, if any, quasi “duty of due care” investigation/analysis requirement remains under the second Read factor becomes significant. While cases have relied on investigative failures to support willfulness, the reasoning and justifications for such conclusions are often shaky at best or simply stated in a confusing manner. Courts will need to sort this out more definitively. But, for their part, patent litigation counsel need to be more consciously aware of these issues so they can be raised and argued when appropriate.
Key Takeaways
Post-Halo, the Federal Circuit applies a two-step process to claims for enhanced patent infringement damages under § 284: willfulness is initially a question for the finder of fact, and then subsequent enhancement, if any, is at the court’s discretion.
Failure to obtain or present an opinion of counsel cannot be used to prove willfulness, though obtaining an opinion can still be valuable to rebut charges of willful infringement; however, the value or necessity of nonattorney patent infringement and validity investigations is not yet clear.
“Willful blindness” has been accepted by many district courts as a willfulness theory, but at the outset it requires plausible pleadings about the accused’s subjective belief that there was a high probability that the asserted patent both existed and was infringed and that the accused took deliberate actions to avoid learning of those facts; “no patent review” policies may or may not meet all of those requirements.
District courts are divided over whether willfulness can be plausibly supported by a failure to monitor or investigate a patent family after learning about an unasserted patent in that family (in the absence of affirmative avoidance of facts akin to willful blindness).
Relevance limits under § 298 have often been overlooked by courts but should be considered for evidentiary objections and motion practice.
Austen Zuege is an attorney at law and registered U.S. patent attorney in Minneapolis whose practice encompasses patents, trademarks, copyrights, domain name cybersquatting, IP agreements and licensing, freedom-to-operate studies, client counseling, and IP litigation. If you have patent, trademark, or other IP issues, he can help.
[ii]. Underwater Devices Inc. v. Morrison-Knudsen Co., 717 F.2d 1380, 1389–90 (Fed. Cir. 1983) (“Where . . . a potential infringer has actual notice of another’s patent rights, he has an affirmative duty to exercise due care to determine whether or not he is infringing,” including “the duty to seek and obtain competent legal advice from counsel before the initiation of any possible infringing activity.”).
[iii]. Knorr-Bremse Systeme Fuer Nutzfahrzeuge GmbH v. Dana Corp., 383 F.3d 1337, 1345–46 (Fed. Cir. 2004) (en banc) (“Although there continues to be ‘an affirmative duty of due care to avoid infringement of the known patent rights of others,’ the failure to obtain an exculpatory opinion of counsel shall no longer provide an adverse inference or evidentiary presumption that such an opinion would have been unfavorable.” (citation omitted)).
[xiii]. WBIP, 829 F.3d at 1341; see alsoSRI Int’l, Inc. v. Cisco Sys., Inc., 930 F.3d 1295, 1310 n.6 (Fed. Cir. 2019) (when willfulness began is a factual issue).
[xvi]. But questions arise where the Federal Circuit appears to suggest that certain levels of intent can support willfulness but not enhanced damages, which seems contrary to Halo. SeeSRI Int’l, Inc. v. Cisco Sys., Inc., 14 F.4th 1323, 1329–30 (Fed. Cir. 2021); see also Austen Zuege, “The Federal Circuit’s Standard for Enhanced Damages,”blue over gray (Oct. 12, 2021). This apparent discrepancy might allow courts to moot a jury’s willfulness finding. SeeSchwendimann v. Arkwright Advanced Coating, Inc., No. 11-cv-820, slip. op. at 50 (D. Minn. July 30, 2018).
[xix]. Global-Tech, 563 U.S. at 769–70; Motiva, 408 F. Supp. 3d at 837 (“By definition, willful avoidance requires more than mere recklessness—and Halo holds that recklessness alone is enough to show willful infringement.”).
[xx]. Bos. Sci., 415 F. Supp. 3d at 494–95; Nonend Inventions, N.V. v. Apple, Inc., No. 2:15-cv-466, 2016 WL 1253740, at *3 (E.D. Tex. Mar. 11, 2016), adopted, No. 2:15-cv-466, 2016 WL 1244973 (E.D. Tex. Mar. 30, 2016).
[xxiii]. CompareVasudevan Software, Inc. v. TIBCO Software Inc., No. C 11-06638, 2012 WL 1831543, at *3 (N.D. Cal. May 18, 2012) (“requisite knowledge of the patent allegedly infringed simply cannot be inferred from mere knowledge of other patents,” such as “the [parent] patent, or, more generally, [the plaintiff’s] ‘patent portfolio’”), andMaxell, Ltd. v. Apple Inc., No. 5:19-cv-00036, slip op. at 9-10 (E.D. Tex. Oct. 23, 2019) (dismissing willfulness allegation based only on knowledge of application and not ultimately issued patent or knowledge of allowance of application), withSIMO Holdings Inc. v. Hong Kong uCloudlink Network Tech. Ltd., No. 1:18-cv-05427, slip op. at 7–9 (S.D.N.Y. Aug. 29, 2019) (rejecting Vasudevan), andOxygenator Water Techs., Inc. v. Tennant Co., No. 20-cv-358, slip op. at 8–13 (D. Minn. Aug. 7, 2020), andSiOnyx, LLC v. Hamamatsu Photonics K.K., 330 F. Supp. 3d 574, 609 (D. Mass. 2018).
[xxiv]. E.g., Schwendimann, No. 11-cv-820, slip. op. at 42 (duty of due care remains abrogated); Biedermann Techs. GmbH & Co. KG v. K2M, Inc., 528 F. Supp. 3d 407, 429 n.17 (E.D. Va. 2021) (noting abrogation issues and not intending to impose duty of due care; allegations were similar to willful blindness).
[xxv]. E.g., Oxygenator Water Techs., No. 20-cv-358, slip op. at 8–13 (passing over willful blindness to find failure to monitor/investigate willfulness theory plausible); Meridian Mfg., Inc. v. C & B Mfg., Inc., 340 F. Supp. 3d 808, 844 (N.D. Iowa 2018). But seeHalo, 136 S. Ct. at 1936 (Breyer, J., concurring) (“‘[W]illful misconduct’ do[es] not mean that a court may award enhanced damages simply because the evidence shows that the infringer knew about the patent and nothing more.”).
[xxxii]. See id. In contrast, enhanced damages were affirmed where the infringer delayed obtaining advice of counsel for years. Arctic Cat Inc. v. Bombardier Recreational Prods. Inc., 876 F.3d 1350, 1371 (Fed. Cir. 2017). There, legal advice was (eventually) obtained and privilege waived, but the delay was held against the infringer.
[xxxiv]. Broadcom Corp. v. Qualcomm Inc., 543 F.3d 683, 699 (Fed. Cir. 2008) (holding that “failure to procure . . . an opinion [of counsel] may be probative of [subjective] intent”).
[xxxvi]. SeeSRI Int’l, Inc. v. Advanced Tech. Labs., Inc., 127 F.3d 1462, 1464–65 (Fed. Cir. 1997) (“[T]he primary consideration is whether the infringer, acting in good faith and upon due inquiry, had sound reason to believe that it had the right to act in the manner that was found to be infringing.” (emphasis added)). Broadcom is still cited without mentioning its statutory abrogation. Omega Pats., 920 F.3d at 1352–53. Compare Broadcom, 543 F.3d at 699, with35 U.S.C. § 298.
[xxxix]. WCM Inds., Inc. v. IPS Corp., 721 F. App’x 959, 970, 970 n.4 (Fed. Cir. 2018) (nonprecedential) (questioning cases suggesting no duty to predict what claims will issue from a pending patent applicable because prosecution histories are now normally publicly available); see alsoSIMO Holdings, No. 1:18-cv-05427, slip. op. at 5–7; 35 U.S.C. §§ 154(d), 284.
[xl]. Halo, 136 S. Ct. at 1936 (Breyer, J., concurring); see alsoSchwendimann, No. 11-cv-820, slip. op. at 42–43; Idenix Pharms. LLC v. Gilead Scis., Inc., 271 F. Supp. 3d 694, 699 (D. Del. 2017). But seeSSL Servs., LLC v. Citrix Sys., Inc., 769 F.3d 1073, 1092 (Fed. Cir. 2014) (excluding lay testimony of belief in invalidity and noninfringement to rebut willfulness).
Prosecution history estoppel can arise when the patentee relinquishes subject matter during the prosecution of the patent—that is, during examination of a patent application at the U.S. Patent & Trademark Office (USPTO)—either by amendment or argument. A narrowing amendment made to satisfy any requirement for patentability (under 35 U.S.C. §§ 101-103, 112, 161, or 171) may give rise to an estoppel. When it applies, prosecution history estoppel will prevent a patentee from relying on the Doctrine of Equivalents to establish infringement based on the particular equivalents surrendered. A given claim limitation might be given only its literal scope (as properly construed) but no more. This policy allows competitors to rely on prosecution history estoppel to ensure that their own devices/processes will not be found to infringe by equivalence.
The Basic Rule
The Doctrine of Equivalents is an equitable doctrine created by courts long ago. It is premised on language’s inability to capture the essence of innovation, allowing some protection beyond the literal scope of a claim where the claimed invention and the accused product or process are equivalent. Its purpose is to “temper unsparing logic” that “would place the inventor at the mercy of verbalism and would be subordinating substance to form” and it evolved in response to situations where accused infringers attempted to “practice a fraud on a patent” by introducing “minor variations to conceal and shelter the piracy.” However, there is a tension between such concerns and the need for patents to put the public on notice of what a patent does and does not cover.
Prosecution history estoppel is about interpreting patent claims by reference to the history that led to their grant. It limits the patentee’s ability to establish infringement by equivalence to help provide certainty to competitors about the enforceable scope of a U.S. patent. Accordingly, the Doctrine of Equivalents is not available where prosecution history shows the inventor was able to capture equivalent differences in words but chose narrower language. The patentee cannot later recapture what was previously surrendered under the guise of the Doctrine of Equivalents. Where the original patent application once embraced the purported equivalent but the patentee narrowed his claims to obtain the patent or to protect its validity, the patentee cannot assert that he or she lacked the words to describe the subject matter in question.
Estoppel Can Arise Through Amendment or Argument
Prosecution history estoppel can arise two ways: (1) by making a narrowing amendment to the claim (amendment-based estoppel) or (2) by surrendering claim scope through argument to the patent examiner (argument-based estoppel). These two possibilities are discussed in turn.
How Amendment-Based Estoppel Can Arise
The first way that prosecution history estoppel can arise is by way of a narrowing amendment to a claim during prosecution. The question of what constitutes a narrowing amendment will depend on the context of a particular patent claim. But a classic example is adding words that narrow the limitations of a claim to avoid a prior art reference cited in a rejection in an office action. As another example, which is less intuitive, courts have said rewriting a dependent claim in independent form is an amendment adding a new claim limitation, which constitutes a narrowing amendment that may give rise to an estoppel.
How Argument-Based Estoppel Can Arise
Argument-based estoppel arises when the prosecution history evinces a “clear and unmistakable” surrender of subject matter. Argument-based estoppel most often arises when the patentee tries to convince a patent examiner that the claims of an application recite something different from the prior art. For instance, a patentee may have argued that a claim term has a meaning that is narrow enough to avoid a disclosure or teaching in a cited prior art reference. In such a situation, the patentee will likely be estopped from later asserting that the Doctrine of Equivalents encompasses what was previously argued to be outside the scope of the claimed invention. Such arguments are treated like an acknowledgement that the patentee knew the meaning of the claim language and deliberately chose narrower language in order to obtain a patent.
Scope of the Estoppel
Though prosecution history estoppel can bar a patentee from challenging a wide range of alleged equivalents used by competitors, its reach requires examination of the particular subject matter surrendered. Even where prosecution history estoppel applies, the scope of the estoppel is not always absolute. These inquiries differ somewhat between amendment-based estoppel and argument-based estoppel.
Scope of Amendment-Based Estoppel
The scope of amendment-based estoppel depends on the claim language at issue and the reason for the amendment. For instance, where the reason for the amendment was not related to avoiding the prior art, it does not necessarily preclude infringement by equivalents of that element. But an amendment to clarify the recitation of the claimed invention to satisfy definiteness requirements for patentability would give rise to an estoppel, even though there was no prior art reference prompting the change. Also, cancellation of a claim can give rise to estoppel with regard to any claim(s) that remain (or are added). However, the reason for an amendment is often not clear from the prosecution history.
When no explanation for an amendment is provided, there is a rebuttable presumption that the Doctrine of Equivalents is not available at all. When the purpose underlying a narrowing amendment cannot be determined—and hence the rationale for limiting the estoppel to surrender of only particular equivalents—it is presumed that the patentee surrendered all subject matter between the broader and the narrower language. But that presumption of amendment-based estoppel can be overcome for a particular equivalent when (1) the equivalent in question was unforeseeable at the time of the application, (2) rationale underlying the amendment bears no more than a tangential relation to the equivalent in question, or (3) the patentee could not reasonably be expected to have described the insubstantial substitute in question.
Scope of Argument-Based Estoppel
The scope of argument-based estoppel is based on the scope of particular arguments made during prosecution. Unlike amendment-based estoppel, there is no presumption-and-rebuttal approach. Rather, the question is how far argument-based estoppel applies in the first place, if at all. The question is whether there was a clear and unmistakable argument-based surrender of particular subject matter. Courts have said that simple arguments and explanations to the patent examiner do not surrender an entire field of equivalents. But any arguments can still surrender some equivalents, even if they do not surrender all possible equivalents. This is very context-dependent. The key to this inquiry is whether a competitor would reasonably believe that the patentee’s argument had surrendered the relevant subject matter.
However, courts have said that any clear assertions made during prosecution in support of patentability, whether or not those assertions were actually required to secure allowance of a claim, may still create an argument-based estoppel. Also, once an argument is made regarding a claim term that creates an estoppel, that estoppel will apply to that term in other claims in the patent too.
Prosecution Disclaimer
Prosecution disclaimer is a separate but related concept. Rather than relating to the availability of the Doctrine of Equivalents to establish infringement, prosecution disclaimer or disavowal can limit the proper construction of a claim’s literal scope. Thus, it may affect whether or not literal infringement is found—prior to any consideration of the Doctrine of Equivalents. For example, it can arise when a patentee makes arguments during prosecution about how the pending claims differ from the prior art. This is meant to prevent patentees from opportunistically taking different (and broader) positions in court when asserting infringement than when obtaining the patent in the first place. Statements made during the prosecution of family-related applications, even later-filed ones and foreign counterparts, may sometimes result in prosecution disclaimer as well.
Questions about prosecution disclaimer pertain to proper claim construction. Claim terms are presumed to carry their full and customary meaning unless the patentee unequivocally imparted a novel meaning to those terms either in the patent application itself (called acting as her own lexicographer) or expressly relinquished claim scope during prosecution. Just as with argument-based estoppel, prosecution disclaimers must be “clear and unmistakable” in order to limit claim scope. An ambiguous statement during prosecution will not limit a claim term’s ordinary meaning.
An important difference between prosecution disclaimer and prosecution history estoppel is when they are taken into account. Prosecution disclaimer is a matter of claim construction. That is something courts do as a first step in patent infringement analyses, without reference to the specific product or process accused of infringement. In contrast, the Doctrine of Equivalents is bound up with the subsequent comparison of the accused product or process to the asserted patent claims as properly construed. Prosecution history estoppel is a question of whether a patent owner is permitted to invoke the Doctrine of Equivalents in particular ways in the second part of infringement analysis, after claim construction. But if literal infringement is found—despite any prosecution disclaimer—there is no need to reach the Doctrine of Equivalents.
Austen Zuege is an attorney at law and registered U.S. patent attorney in Minneapolis whose practice encompasses patents, trademarks, copyrights, domain name cybersquatting, IP agreements and licensing, freedom-to-operate studies, client counseling, and IP litigation. If you have patent, trademark, or other IP issues, he can help.
At a most basic level, patent infringement in the U.S. involves making, using, selling, offering for sale, importing into the USA a patented invention without authorization. Although there are some additional grounds for infringement that may apply in some other circumstances. All grounds for infringement fall into two general categories: direct infringement and indirect infringement. These categories refer to who is being accused and whether they are directly responsible or instead indirectly or partly responsible. There are multiple types of infringement under each category. These include literal or Doctrine of Equivalents infringement, and, for indirect infringement, active inducement of infringement, contributory infringement, and certain activities related to components for export from the USA. Each of these provisions, set forth in § 271 of the U.S. patent laws, is taken up further below.
Direct Infringement
Direct patent infringement means that an accused party is directly responsible for infringement a patent. Direct infringement requires that each and every limitation (or element) of at least one claim of an asserted patent is met either literally or under the Doctrine of Equivalents. If a limitation of a given patent claim is not present in the accused product or process, either literally or equivalently, then that claim is not infringed.
The sorts of things that can constitute direct infringement include the following:
making (that is, manufacturing) the patented invention in the USA (35 U.S.C. § 271(a))
submitting a new drug application for U.S. regulatory approval (Hatch-Waxman Act; 35 U.S.C. § 271(e))
importing into the USA, or offering to sell, selling, or using within the USA, a product which is made outside the USA by a process patented in the USA, unless it is materially changed by subsequent processes or it becomes a trivial and nonessential component of another product (35 U.S.C. § 271(g))
Certain additional rights to exclude specific to plant patents (35 U.S.C. § 163)
There are two ways of finding infringement that differ in terms of how the accused product or process relates to the scope of the claim(s) of the asserted patent:
Literal Infringement
Infringement Under the Doctrine of Equivalents (also called infringement by equivalence)
Literal Infringement
Literal infringement means that the accused product or process falls within the scope of the asserted claim(s) as construed by a court. Under U.S. law, infringement analysis is a two-step process. It involves, first, construing the claims to ascertain their meaning to a person of ordinary skill in the art and to resolve any ambiguities or disputes over that meaning, and, second, comparing the accused product/process to the properly construed claim(s). Literal infringement is present when the accused infringer meets each and every limitation (or element) of an asserted patent claim exactly, as properly construed. Any deviation from a claim limitation (as properly construed) precludes a finding of literal infringement.
Infringement Under the Doctrine of Equivalents
Under the Doctrine of Equivalents, a product or process that does not literally infringe upon the express terms of a patent claim may nonetheless still be found to infringe if there is “equivalence” between the elements of the accused product or process and claimed elements of the patented invention. This type of infringement arises when the accused product or process is outside the literal scope of at least one limitation of an asserted claim, as properly construed. Patentees rely on the Doctrine of Equivalents under the second step of the infringement analysis, if at all, only if literal infringement cannot be established. Otherwise, the Doctrine of Equivalents can apply to the same set of activities as for literal infringement.
This is an equitable doctrine meant to “temper unsparing logic” that “would place the inventor at the mercy of verbalism and would be subordinating substance to form.” It evolved in response to situations where accused infringers attempted to “practice a fraud on a patent” by introducing “minor variations to conceal and shelter the piracy.” Of course, the doctrine is in tension with the policy requiring that claims put the public on notice of a patent’s scope. This is a reason the Doctrine of Equivalents is not meant to be routinely invoked and is not applied broadly. In other words, this type of infringement is a limited exception to the general rule that patent claims must reasonably put others on notice of the outermost boundaries of what constitutes infringement. Put another way, it allows a limited form of “central” claim enforcement in a regime of “peripheral” claiming.
The Doctrine of Equivalents is applied individual claim limitations rather than to the claimed invention as a whole. To find infringement, each claim limitation (or element) must be found either literally or equivalently in the elements of accused product/process. This is called the “all elements” rule. The question of equivalence is inapplicable if a claim limitation is totally missing from an accused device. The Doctrine of Equivalents cannot be used to re-draft claims and effectively eliminate limitations entirely. Though this inquiry always revolves around what differences can reasonably be considered equivalent. An undue expansion of a patent’s claim(s) is not permitted. After-arising technology can potentially be encompassed by the Doctrine of Equivalents (unlike for means-plus-function equivalents).
There are two approaches to assessing equivalents: the “insubstantial differences” test and the “function-way-result” test. The function-way-result test (also called the “triple identity” test) says that equivalence may be present for a given element if the accused product/process performs substantially the same function in substantially the same way with substantially the same result. This is not the only way to assess whether differences are insubstantial, but it is particularly useful for certain types of inventions such as mechanical devices. For biochemical inventions, however, looking at substantial differences may sometimes be more appropriate than the function-way-results test.
There are numerous limits on the Doctrine of Equivalents, which are really beyond this basic introduction. But an extremely important limit on the availability of the Doctrine of Equivalents is prosecution history estoppel. Things that the patentee did or said when obtaining the asserted patent might limit the patentee’s ability to later rely on the Doctrine of Equivalents. So the Doctrine of Equivalents is not always or automatically available.
Indirect Infringement
Indirect patent infringement means that an accused party is causing or enabling someone else to infringe. It can apply when an accused infringer meets some but not all of the limitations (or elements) of an asserted patent claim. It includes three types of infringement, which differ in terms of what the accused indirect infringer is doing:
Supplying Component for Export for Combination Outside the USA (35 U.S.C. § 271(f))
Generally speaking, there are additional requirements that must be satisfied to establish indirect infringement that are not required for direct infringement. Those additional requirements vary depending on what type of indirect infringement is asserted.
Also, relevant limitations of asserted claim(s) can be assessed under either their literal scope or under the Doctrine of Equivalents, if available—see discussions above of literal and Doctrine of Equivalents infringement for direct infringement. This is really to say that the Doctrine of Equivalents may still apply to indirect infringement scenarios.
Active Inducement of Infringement
Actively inducing someone else to infringe a patent constitutes inducement of infringement. Specifically, “[w]hoever actively induces infringement of a patent shall be liable as an infringer.” (35 U.S.C. § 271(b)). This is a form of vicarious liability. Active inducement requires taking an affirmative steps to encourage infringement by another entity, as well as knowledge that the encouraged acts infringe the asserted patent. A key component of inducement is that it requires there be at least one direct infringer. But the difference here is that instead of suing the direct infringer, a different entity is sued for inducement.
Inducement commonly arises in situations involving claims to a method of using a product. Rather than sue the end user, which may be a potential customer, the patentee instead sues a competitor making and selling products used by others to (directly) perform and infringe the asserted method claim(s). It also sometimes arises where a corporate officer or owner induces his or her company to infringe, making that individual personally liable for infringement.
Contributory Infringement
Contributory infringement arises when selling, offering to sell, or importing components that are specially made or adapted for use to infringe a patent. However, contributory infringement excludes activities involving a staple article or commodity of commerce that is suitable for substantial noninfringing use. A “substantial noninfringing use” is any use that is not unusual, far-fetched, illusory, impractical, occasional, aberrant, or experimental. So there is normally no liability for selling general-purpose commodities, even if they could be used in making or using a patented invention.
“(c) Whoever offers to sell or sells within the United States or imports into the United States a component of a patented machine, manufacture, combination or composition, or a material or apparatus for use in practicing a patented process, constituting a material part of the invention, knowing the same to be especially made or especially adapted for use in an infringement of such patent, and not a staple article or commodity of commerce suitable for substantial noninfringing use, shall be liable as a contributory infringer.”
In order for contributory infringement to be present, the infringer must know that the combination for which his component was especially designed was both patented and infringing. This knowledge requirement differentiates contributory infringement from direct infringement, which does not require any such knowledge of the patent or infringement (except to enhance damages).
Contributory infringement is important for situations involving the sale of repair or replacement parts for use in or with patented products or methods.
Supplying Component for Export for Combination Outside the USA
Section 271(f) of the patent laws creates two grounds for infringement involving activities in the USA relating to products made in a foreign country. They arise when components of a patented invention are supplied for export from the USA. These grounds for infringement are similar to yet distinct from active inducement and contributory infringement, discussed above. But these provisions do not require that the equivalent of “foreign” direct infringement occur. That is, the actual combination need not actual occur. However, these provisions apply exclusively to apparatus claims, and are not available for method/process claims. They also do not apply to activities that occur entirely outside the USA. Also, § 271(f)(1) has a quantitative requirement about the number of components involved and it does not apply to only a single component.
“(f)
(1) Whoever without authority supplies or causes to be supplied in or from the United States all or a substantial portion of the components of a patented invention, where such components are uncombined in whole or in part, in such manner as to actively induce the combination of such components outside of the United States in a manner that would infringe the patent if such combination occurred within the United States, shall be liable as an infringer.
(2) Whoever without authority supplies or causes to be supplied in or from the United States any component of a patented invention that is especially made or especially adapted for use in the invention and not a staple article or commodity of commerce suitable for substantial noninfringing use, where such component is uncombined in whole or in part, knowing that such component is so made or adapted and intending that such component will be combined outside of the United States in a manner that would infringe the patent if such combination occurred within the United States, shall be liable as an infringer.”
The grounds for infringement under § 271(f) are somewhat rarely invoked. This is largely because manufacturing costs are often higher in the USA than abroad. As a result, courts have not extensively clarified the scope and proper application of these provisions. But suffice it to say they may apply in situations where components are being produced and/or sold in the USA for export.
Austen Zuege is an attorney at law and registered U.S. patent attorney in Minneapolis whose practice encompasses patents, trademarks, copyrights, domain name cybersquatting, IP agreements and licensing, freedom-to-operate studies, client counseling, and IP litigation. If you have patent, trademark, or other IP issues, he can help.
Intellectual property (IP) litigation tends to be relatively expensive compared to other types of lawsuits. There are many reasons for that. Though the complexity of the legal issues involved and a tendency for extensive pre-trial discovery and use of expert witnesses contribute to the total costs.
Below are graphs showing average costs through various stages of a an infringement or misappropriation lawsuit in the U.S. A summary graph compares average costs for “small” patent, copyright, trademark, and trade secret cases with less than $1,000,000 at risk. There are also individual graphs for patent, copyright, trademark, and trade secret cases with different amounts at risk, that is, with different amounts of potential damages for infringement or misappropriation (in U.S. dollars). All data comes from the 2021 AIPLA Report of the Economic Survey.
Comparison of Average “Small” IP Lawsuit Costs by Type of Case and Stage
Average Patent Litigation CostsAverage Copyright Litigation Costs
Austen Zuege is an attorney at law and registered U.S. patent attorney in Minneapolis whose practice encompasses patents, trademarks, copyrights, domain name cybersquatting, IP agreements and licensing, freedom-to-operate studies, client counseling, and IP litigation. If you have patent, trademark, or other IP issues, he can help.
Patent marking can be important for obtaining full recovery of infringement damages. When enforcing a patent against an infringer in the United States, damages for infringement of a patented article can usually be recovered only from the date the infringer had actual or constructive notice of the patent(s), whichever comes first. Actual notice requires the affirmative communication of a specific charge of infringement, such as in a cease-and-desist letter or filing an infringement lawsuit. Constructive notice is established by the patentee properly marking patented articles, regardless of whether a particular infringer actually sees that patent notice on products.
The following is a brief overview of basic U.S. patent marking legal requirements as well as guidance about how to properly implement patent marking. A more detailed treatment (with extensive examples) is provided in the Patent Marking Guide.
The U.S. Marking Requirement
The U.S. patent laws provide the following statutory marking requirement:
“Patentees, and persons making, offering for sale, or selling within the United States any patented article for or under them, or importing any patented article into the United States, may give notice to the public that the same is patented, either by fixing thereon the word ‘patent’ or the abbreviation ‘pat.’, together with the number of the patent, or by fixing thereon the word ‘patent’ or the abbreviation ‘pat.’ together with an address of a posting on the Internet, accessible to the public without charge for accessing the address, that associates the patented article with the number of the patent, or when, from the character of the article, this can not be done, by fixing to it, or to the package wherein one or more of them is contained, a label containing a like notice. In the event of failure so to mark, no damages shall be recovered by the patentee in any action for infringement, except on proof that the infringer was notified of the infringement and continued to infringe thereafter, in which event damages may be recovered only for infringement occurring after such notice. Filing of an action for infringement shall constitute such notice.”
These statutory marking requirements apply to all types of U.S. patents: utility, design, and plant. Having a marking requirement helps to avoid innocent infringement situations, among other things.
Patent Marking Provides Constructive Notice
Marking patented articles provides constructive notice to the public that an article is patented. To be legally sufficient to establish constructive notice, the patentee must be able to establish that substantially all of the patented articles being distributed were marked, and that once marking was begun, the marking was substantially consistent and continuous. If marking is defective at first, curing those defects going forward is possible. But full compliance with marking requirements to provide constructive notice to infringers is not achieved until the time the patentee consistently marked substantially all of the patented products, and if marking was deficient for a time then constructive notice will not be provided unless and until proper marking occurs with subsequent sales.
Possible Exceptions to Marking Requirements
The most important exception to the marking requirement is where the patentee has not sold any patented articles. When there are no products to mark, there is no failure to mark and therefore no bar to recovery of pre-suit damages.
Additionally, because the marking statute refers only to a “patented article”, patents with method or process claims are treated differently. Neither marking (constructive notice) nor actual notice is required to obtain back damages for infringement of asserted patents having only method or process claims. For patents having both apparatus and method claims, marking might still be required (if apparatus claims are asserted) and is therefore recommended.
Licensee(s) and Other Authorized Parties Must Mark Too
Marking requirements apply not only to the patentee but anyone making, selling, or offering for sale the patented article “for or under” the patentee or importing it into the U.S. Where a patent is licensed to another, expressly or impliedly, or is the subject of a covenant not to sue or the like, the other entity is required to mark as well. Authorized activities by an outsourced manufacturer or authorized seller are treated as if they are by the patentee in terms of marking requirements in this respect. Failure of a licensee or other authorized user to consistently mark substantially all licensed products will frustrate efforts to establish constructive notice. This requirement for licensees and authorized users is subject to a rule of reason. Some instances of omitted marking by others might be excused so long as the patentee makes reasonable efforts to ensure their compliance with marking requirements. It is recommended that any license for a U.S. patent obligate the licensee to comply with marking requirements, and/or that a part sold so that a downstream purchaser or user will specifically use it to assemble a patented article carry a “for use under” marking notice.
How to Implement Patent Marking: Two Possibilities
There are two ways to mark patented articles in accordance with U.S. law: physical or virtual marking.
Physical Marking
Physical patent marking (which can also be called conventional or traditional marking) involves fixing notices on the patented articles themselves in a way that associates the patented article with the number of the patent. Such a notice must include the word “patent” or the abbreviation “pat.”, together with the number of the patent.
If the nature of the patented article means such a notice cannot be fixed to the patented article itself, such as due to size constraints or where the article is a fluid, the notice can instead be placed on a label fixed either to the patented article or to a package containing one or more of the patented articles. This is an alternate form of physical marking that is appropriate when there is a legitimate reason the notice is not directly affixed to the article.
An example of a proper physical patent marking notice (for the fictitious U.S. Pat. No. 00,000,000) would be the following fixed directly on an article covered by the claims of the indicated patent:
Pat. 00,000,000
If multiple patents apply to the same patented article, they can be listed together. It is not necessary to repeat the word “patent” or abbreviation “pat.” before each patent number in such a list. Pluralizing the word “patent” is generally fine, as is the presence of an additional word or abbreviation, such as in “patent number 00,000,000” or “pat. nos. XX,XXX,XXX and YY,YYY,YYY”. The use of “U.S. patent” or “U.S. pat.” would also be acceptable. The text of the notice should be in English.
Virtual Marking
Virtual patent marking is an acceptable alternative to physical marking. It can be useful in situations where all the patent information required to provide constructive notice cannot easily fit on the patented article or even its label, such as where there are multiple patents that apply to an article that is fairly small in size. As the number of digits in patent numbers increase, this sort of difficulty increases. Virtual marking can also be helpful in situations where different patents are associated with different products but having product-specific labels is burdensome—a single label might be used listing a URL for a web page with patent association information for multiple products. Virtual marking can also minimize the need to replace or modify molds used to create a patent marking notice directly on molded articles as new patents issue or existing patents expire.
Implementing virtual patent marking involves fixing notices on the patented articles themselves in a way that associates the patented article with the number of the patent. Such a virtual marking notice must use the word “patent” or the abbreviation “pat.” together with an address of a posting on the Internet (that is, a web page URL), accessible to the public without charge for accessing the address. If the nature of the patented article makes means such a notice cannot be fixed to the patented article itself, the virtual marking notice (indicating “patent” or “pat.” together with a URL) can instead be placed on a label fixed either to the patented article or to a package containing one or more of the patented articles.
An example of a proper virtual patent marking notice fixed on a patented article or its label is the following:
Pat. www.example.com/patents
The main feature of virtual patent marking is that the information associating the patented article with the number(s) of the patent(s) that cover it appears on a freely-accessible web page rather than directly on the article or its label. There is still a requirement for a notice on the patented product or its label. A marking web page, alone, is insufficient unless there is also a proper notice on the patented product or its label to direct people to that web page’s address. Moreover, a virtual marking notice on a product or its package is insufficient without an acceptable posting accessible from the identified Internet address.
The difference between physical and virtual marking really involves the manner of conveying the required association between the patent number(s) and the patented article. With traditional physical patent marking, the association is implicit in terms of which patent numbers are including in or omitted from a notice fixed to a particular product or its label. In virtual marking, the notice fixed to the product or its label merely directs the public to a web page but the web page must further provide an association between given patent(s) and the specific product(s) that practice those patent(s).
Courts have said that virtual patent marking does not allow a patentee to avoid the traditional burden of determining which patent(s) apply to specific products and indicating that patent-to-product association. The patentee cannot shift that burden to the public. A web page that presents a “research project” forcing visitors to determine patent-to-product association(s) on their own fails to provide constructive notice. Any web page lacking the required “association” between the patent(s) and patented article(s) is legally deficient and will not provide constructive notice allowing recovery of pre-suit infringement damages.
Certain courts have found the following to be insufficient for virtual marking:
A web page listing all of a company’s patents with an indication that “one or more” listed patents “may be used” with a given product
A web page listing multiple patents and grouping them by product category, without indicating which specific products within each category were covered by specific patents
A table on a web page listing patent numbers and titles but lacking any product information (where the company sold multiple products and one was unrelated to its patents)
Patent-to-product associations indicated somewhere other than on the virtual patent marking web page
Failing to put a notice indicating a virtual marking URL on hardware sold by a licensee that had pre-installed software that made the combined hardware-plus-software product subject to an asserted patent
False Patent Marking Prohibited
An important related concept is false patent marking. False marking generally involves marking products as patented when they are not, or marking products as “patent pending” when no patent application has been filed, with an intent to deceive. It also applies to intentional counterfeiting. Penalties apply to intentional false marking (35 U.S.C. § 292). Although the patent laws exclude from the scope of false marking the indication of an expired patent that once applied to the marked product. Also, there is no liability for honest mistakes about whether or not a patent applies.
It is important to only use patent marking where there is a reasonable basis to believe that the product is covered by the indicated patent(s). Patents that do not apply to a given product must not be marked on it (consider also any invalidation or cancellation of a given patent for continued marking). In the virtual marking context, patent-to-product associations must be specific enough to avoid false marking. Imprecise, blanket statements on virtual marking web pages implicating multiple patents and multiple products might give rise to false marking if done for purposes of deceiving the public about which patents, if any, apply to particular products. More generally, avoid marking products with any “patented” language that is confusing, geographically vague, or misleading with respect to that product’s patent status in the USA.
Austen Zuege is an attorney at law and registered U.S. patent attorney in Minneapolis whose practice encompasses patents, trademarks, copyrights, domain name cybersquatting, IP agreements and licensing, freedom-to-operate studies, client counseling, and IP litigation. If you have patent, trademark, or other IP issues, he can help.
There are many situations where it is desirable to challenge the validity or patentability of a granted patent or pending patent application. For instance, an invalidity search can be useful for an invalidity opinion to mitigate infringement liability, an invalidity defense in litigation, a proactive challenge to patentability at the U.S. Patent & Trademark Office (USPTO), or a pre-issuance submission (observations) to try to restrict or prevent a patent from being issued. But what is the best timing for such an invalidity search?
In one sense, an invalidity search is never strictly legally required. Though, practically speaking, invalidity searches are often crucial to avoiding or reducing liability for patent infringement in many contexts. These searches must be performed in a timely manner to obtain the greatest value from them. That includes performing searches in time to meet deadlines that require having suitable search results available.
Patent invalidity searches are reactive in the sense of being conducted in response to some infringement risk arising. That could be the receipt of a cease & desist letter, the filing of an infringement lawsuit against you, or other knowledge of a potentially problematic patent (e.g., via a freedom-to-operate study). In any event, an invalidity search requires first knowing which patent is the subject of the invalidity search. That is because an invalidity search depends on the scope of the particular claim(s) of concern and their effective filing date(s)—including any priority date(s).
It is a best practice to consider an invalidity search after a tangible risk of patent infringement comes to your attention. Knowledge of a patent coupled with a reasonable belief that infringement might be present can potentially give rise to enhanced damages for infringement. And knowledge of a pending patent application can potentially give rise to so-called “provisional rights” to pre-issuance infringement damages.
There may be deadlines that determine when invalidity search results are needed. For instance, in patent litigation in a district court, the court will issue a scheduling order that often sets a deadline to set for invalidity contentions. In is necessary to have search results available in order to formulate those invalidity contentions and prepare a suitable report. Other times, invalidity contentions might be requested through discovery requests, such as interrogatories. Either way, it is crucial to perform the invalidity search far enough in advance of such deadlines to allow for subsequent legal analysis of the search results.
Moreover, there are situations where a proactive challenge to a granted patent is desired. Proceedings such as inter partes review (IPR), post-grant review (PGR), oppositions, and the like may have various different deadlines by which a challenge must be filed. Such deadlines drive the timeline for completing invalidity searching. Just as in litigation, the search must be completed with time to spare to allow for legal analysis and preparation of any formal filing papers for the patent challenge, which may require considerable effort to prepare. Additionally, a pre-issuance submission (or observation) might be filed against a pending patent application and there likewise are both formal and practical deadlines to do so.
Lastly, if an opinion of counsel setting forth grounds for liability is desired to mitigate potential infringement damages, such an opinion should ideally be obtained before your relevant product (or process) is commercially launched. If patent in question is discovered only later, then such an opinion should be obtained without unreasonable delay. Having invalidity search results is a prerequisite to completing an invalidity opinion.
In all these possible settings, it is common for multiple invalidity searches to be performed. That can include follow-on invalidity searches performed in an iterative manner, in order to exhaustively locate prior art and to try to obtain sufficient prior art for desired (and reasonable) invalidity arguments as those arguments evolve and develop. It may also include searches performed by different searchers in different databases (including in non-patent literature databases), in different native languages, though investigation of prior public use and on-sale activities, and the like.
Have an invention you would like to patent? Have a brand you would like to register as a trademark? Concerned about infringing someone else’s intellectual property? Is someone else infringing your IP? Need representation in an IP dispute? Austen is a patent attorney / trademark attorney who can help. These and other IP issues are his area of expertise. Contact Austen today to discuss.
Is it possible for a U.S. design patent claim to include a negative limitation? It does not appear that courts have explicitly addressed this question. That is partly due to emphasis on design patent claims and infringement analyses revolving around the design as a whole, which can lead to rather conclusory decisions. But the question posed here is whether a claimed ornamental design as a whole can contain within it one or more “negative limitations” that effectively indicate the absence of some ornamental aspect, as opposed to indicating the positive (or affirmative) presence of an ornamental aspect. Certain past cases have touched on similar issues without specific reference to “negative limitations” in the sense that term is used with regard to utility patent claims.
Consider a design patent claim that shows as part of the overall ornamental design a flat surface, that is, a solid planar surface that is plain and uninterrupted. Does such a depiction include a negative limitation of sorts that excludes the presence of ornamentation on the surface? That is, does it give rise to a potentially significant overall difference when comparing a perforated surface or a surface that has substantial non-planar texturizing surface ornamentation? The same questions might arise, for instance, when a claimed design depicts only a single element (such as a single rounded corner, single support bar, single hole, etc.) but the accused product includes more than one of those elements.
In general, design patent infringement analysis involves two steps: (1) claim construction and (2) comparison of the properly construed claim to the accused product. Elmer v. ICC Fabricating, Inc., 67 F.3d 1571, 1577 (Fed. Cir. 1995). Theoretically, at least, questions about “negative limitations” in design patents could potentially arise in either of those two steps.
While, certainly, a jury can always reach an ultimate infringing/non-infringing conclusion, in the binary sense, based on the particular and specific facts at hand in any given case. But the topics at hand here are how courts should treat the legal issues surrounding how a finder of fact might be presented with design patent infringement questions where negative limitation issues are present, and also how courts making dismissal (Rule 12(b)(6)), summary judgment, judgment on the pleadings, judgment as a matter of law (JMOL), or appeal decisions can explain their reasoning under the ordinary observer test when negative limitations may be present.
Negative Limitations in Design Claim Construction
Design patent infringement analysis begins with claim construction. Although claim construction is also the first step in utility patent infringement analysis, design patent claim construction differs from that for utility patents in some important ways.
A patentable design “gives a peculiar or distinctive appearance to the manufacture, or article to which it may be applied, or to which it gives form.” Gorham Co. v. White, 81 U.S. (14 Wall.) 511, 525 (1871); see also Samsung Elecs. Co., Ltd. v. Apple Inc., 580 U.S. ___, 137 S. Ct. 429, 432-33 (2016). This means design patent claim construction must be adapted to the pictorial setting. Crocs, Inc. v. Int’l Trade Comm’n, 598 F.3d 1294, 1302 (Fed. Cir. 2010). In that sense, the Federal Circuit has said that “[d]epictions of the claimed design in words can easily distract from the proper infringement analysis of the ornamental patterns and drawings.” Id.; see also Dobson v. Dornan, 118 U.S. 10, 14 (1886) (a claimed design “is better represented by the photographic illustration than it could be by any description, and a description would probably not be intelligible without the illustration.”).
The Federal Circuit has cautioned that detailed verbal claim constructions increase “the risk of placing undue emphasis on particular features of the design and the risk that a finder of fact will focus on each individual described feature in the verbal description rather than on the design as a whole.” Egyptian Goddess, Inc. v. Swisa, Inc., 543 F.3d 665, 680 (Fed. Cir. 2008) (en banc). For such reasons, the level of detail to be used in describing the claimed design is a matter within a court’s discretion, and a court is not obligated to issue a detailed verbal description of the design if it would not be helpful. Id. at 679-80. Yet a court may use claim construction to help guide the fact finder through issues that bear on claim scope. Id. at 680.
Although not always at issue in every case, design patent claim construction can address prosecution history estoppel and prosecution history disclaimer. See Egyptian Goddess, 543 F.3d at 680. In general, the doctrine of prosecution history estoppel prevents a patentee from “recaptur[ing] in an infringement action the very subject matter surrendered as a condition of receiving the patent.” Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722, 734 (2002). It requires that “the claims of a patent be interpreted in light of the proceedings in the [US]PTO during the application process.” Id. at 733. The Federal Circuit has specifically held that prosecution history estoppel applies to design patents too. Pac. Coast Marine Windshields Ltd. v. Malibu Boats, LLC, 739 F.3d 694, 702 (Fed. Cir. 2014).
However, for design patents, unlike with utility patents, “the concepts of literal infringement and equivalents infringement are intertwined.” Id. at 700-01. Because it is the drawings of the design patent that provide the description of the invention, courts “look at the requisite drawings in design patents to determine whether a surrender has occurred.” Id. at 702. Estoppel arises when a narrowing amendment is made to satisfy any requirement to secure the grant of the patent, including amendments to avoid prior art or resulting from a restriction requirement. Id. at 703-04; see also Advantek Marketing Inc. v. Shanghai Walk-Long Tools Co., 898 F.3d 1210, 1216-17 (Fed. Cir. 2018).
In the Pacific Coast Marine Windshields case, a design application (for U.S. Des. Pat. No. D555,070) originally included drawings depicting—and claiming—multiple embodiments of a boat windshield. As reproduced below, the various originally-claimed embodiments showed the claimed windshield design with different vent hole configurations and also showed claimed designs that included and excluded a hatch on the front of the windshield. The examiner issued a five-way restriction requirement, identifying five distinct groups of designs as windshields with:
four circular holes and a hatch (FIG. 1);
four circular or square holes and no hatch (FIGS. 7 and 12);
no holes and a hatch (FIG. 8);
no holes and no hatch (FIG. 9); and
two oval or rectangular holes and a hatch (FIGS. 10 and 11).
Grid of selected original figures from the application for Des. Pat. No. D555,070
In that sense, the examiner indicated that many of the different embodiments (but not all of them) represented different design inventions. In response, the patentee removed alternate embodiments, thus deleting those alternate embodiments from the scope of the claim. That prosecution history had significant implications to the scope of the claim in the granted design patent before the court (D555,070). Incidentally, the patentee chose to file only one subsequent divisional application to the “no holes and a hatch” embodiment (that became U.S. Des. Pat. No. D569,782), apparently without pursuing any other of the original alternate embodiments—though a continuation application (that became U.S. Des. Pat. No. D593,024) based off the divisional was also later filed for a partial design to only the vertical corner posts with no vent holes (with the windscreen portions unclaimed, thus potentially avoiding hatch vs. no hatch questions).
Malibu Boats, LLC’s accused product (left) and FIG. 1 of U.S. Pat. No. D555,070 (right)
Noting that treatises and prior district court decisions had said similar things in the past, the Federal Circuit ruled that surrender of claims to the alternate designs was for reasons of patentability that caused prosecution history estoppel to attach. Pac. Coast Marine Windshields, 739 F.3d at 702-04. However, because the accused windshield product’s design had three vent holes (see above) but the patented design had four vent holes (see FIG. 1 above) and the surrendered embodiments/designs had only two vent holes (see original FIGS. 10 and 11 above), summary judgment of non-infringement was reversed and the case was remanded to the district court for further proceedings. Id. at 704-05. In other words, without reaching a definitive infringement/non-infringement decision, the patentee was barred from arguing that the design patent’s claim covered a two-hole design (or any other surrendered embodiments) but was still able to argue that a three-hole design might be covered because there was no surrendered three-hole embodiment in the original drawings. (The Federal Circuit decision did not address potential differences in the horizontal/angled frame or trim aspects of the accused design as part of the overall appearance analysis). After remand, and denial of subsequent summary judgment cross motions (which included inventorship disputes, and non-patent issues), the parties eventually settled.
Generally similar negative limitation issues have arisen in utility patent cases. For example, the Spine Solutions case involved questions of claim construction and prosecution history estoppel for a utility patent. Claim 1 of the patent in question recited “a single anchor on each of the upper surface of the upper part and the lower surface of the lower part . . . .” The relevant claim construction implicitly regarded the “single anchor” recitation as including a negative limitation, that is, requiring one anchor having the recited characteristics but excluding the presence of more than one anchor. There was no infringement by the accused device, which had two anchors rather than a “single” anchor as claimed. The Federal Circuit reasoned as follows:
“We agree with [the accused infringer] Medtronic that the court erred in determining that [the accused] O-Maverick [device] literally infringes claims 1 and 2. The [district] court construed ‘single anchor’ to mean, in relevant part, that ‘[t]he upper and lower surfaces of the implant each have one anchor having the characteristics recited in the last paragraph of [claim 1].’ Claim Construction Order, 2008 WL 4831770, at *14, 2008 U.S. Dist. LEXIS 116648, at *43 (emphasis added). A simple observation of [the accused] O-Maverick [device] confirms that the implant has two anchors on each of the upper and lower pieces, not one. The anchors are separated by a one-millimeter gap that extends all the way to the base of the implant; at no point are the two anchors joined or connected in any way. O-Maverick clearly has two anchors on each piece, not a ‘single anchor’ as recited by claims 1 and 2. Therefore, we hold as a matter of law that [the accused] O-Maverick [device] does not literally infringe claims 1 and 2.
“During prosecution, applicants expressly distinguished the claimed invention over the ‘477 patent by asserting that ‘a reference disclosing two anchors does not disclose a device affirmatively claiming a single anchor… reciting a negative limitation in the form of a single element is not disclosed by prior art which teaches more than one element.’ J.A. 17524. This is a clear disclaimer of claim scope, and prosecution history estoppel therefore bars [the patentee] SSI from arguing that a two-anchor device is equivalent to the claimed implant. Because we hold that [the accused] O-Maverick [device] is a two-anchor device, SSI cannot argue that O-Maverick infringes claims 1 and 2 under the doctrine of equivalents.”
What all these cases emphasize is that negative limitations can be at issue for design patent claim constructions, just as in utility patent cases. Prosecution disclaimer or prosecution estoppel issues resulting from arguments or amendments to a design application are especially relevant here. The Pacific Coast Marine Windshields case illustrates how those issues should be assessed as part of a design claim construction, if and when they arise. Other cases also indicated how this can be significant with respect to words in the design patent claim — such as words in the title that restrict the scope of the claim to a particular article of manufacture. Curver Luxembourg, SARL v. Home Expressions Inc., 938 F.3d 1334, 1340 (Fed. Cir. 2019); In re SurgiSil, L.L.P., No. 2020-1940 (Fed. Cir. Oct. 4, 2021). It is possible a design patent might include words like “individual” in the title that could include a negative limitation.
What is less certain for design patent claim construction is what role, if any, negative limitations have when the feature in question is something that appears in a drawing but there was no prosecution history disclaimer or estoppel. Because detailed design claim constructions that translate visual depictions into words are disfavored, it would not be appropriate in most situations to single out a particular visual element and explicitly construe it as containing a negative limitation (in the absence of a disclaimer or estoppel). That would depart from the context of the ordinary observer analysis and the requisite visual analysis of the overall appearance of the ornamental design.
Yet there may be instances where a negative limitation appears in relation to functional features, for example. The Federal Circuit has held that a claim construction may help the fact finder “distinguish[] between those features of the claimed design that are ornamental and those that are purely functional.” Egyptian Goddess, 543 F.3d at 680 (citing OddzOn Prods., 122 F.3d at 1405). A design may contain both functional and ornamental elements, even though the scope of a design patent claim “must be limited to the ornamental aspects of the design.” Ethicon Endo-Surgery, Inc. v. Covidien, Inc., 796 F.3d 1312, 1333 (Fed. Cir. 2015). “Where a design contains both functional and non-functional elements, the scope of the claim must be construed in order to identify the non-functional aspects of the design as shown in the patent.” OddzOn Prods., 122 F.3d at 1405; accord Ethicon Endo-Surgery, Inc., 796 F.3d at 1333. This ensures that the claim is limited to the ornamental aspects of the design, and does not extend to “the broader general design concept.” OddzOn Prods., Inc., 122 F.3d at 1405; see also Read Corp. v. Portec, Inc., 970 F.2d 816, 825 (Fed. Cir. 1992) (“[w]here . . . a design is composed of functional as well as ornamental features, to prove infringement a patent owner must establish that an ordinary person would be deceived by reason of the common features in the claimed and accused designs which are ornamental.”). But a construction of design features that are only partly functional, with some at least minimal ornamentation, must not entirely eliminate whole aspects from the scope of the claim, even as the functional elements limit and narrow the claim scope. See Sport Dimension, Inc. v. Coleman Co., Inc., 820 F.3d 1316, 1322-23 (Fed. Cir. 2016); Apple Inc. v. Samsung Elecs. Co., Ltd., 786 F.3d 983, 998-99 (Fed. Cir. 2015).
Negative Limitations in Comparisons Between Claimed Design and Accused Product
Following claim construction, if any, the design patent’s claim as construed is compared to the allegedly infringing products. Elmer, 67 F.3d at 1577. When considering infringement of a design patent, the “ordinary observer” test is the sole test for determining if infringement has occurred. Egyptian Goddess, 543 F.3d at 678 (rejecting the use of a separate “point of novelty” test); Crocs, 598 F.3d at 1303. Under the ordinary observer test, infringement occurs:
“if, in the eye of an ordinary observer, giving such attention as a purchaser usually gives, two designs are substantially the same, if the resemblance is such as to deceive such an observer, inducing him to purchase one supposing it to be the other, the first one patented is infringed by the other.”
Gorham, 81 U.S. at 528; Egyptian Goddess, 543 F.3d at 670-71.
This test has been codified in the patent laws, which provide as follows:
“Whoever during the term of a patent for a design, without license of the owner, (1) applies the patented design, or any colorable imitation thereof, to any article of manufacture for the purpose of sale, or (2) sells or exposes for sale any article of manufacture to which such design or colorable imitation has been applied shall be liable to the owner to the extent of his total profit, but not less than $250, recoverable in any United States district court having jurisdiction of the parties.”
35 U.S.C. § 289
Thus, as the ordinary observer test is sometimes described, infringement is not found unless the accused article embodies the patented design or any colorable imitation of it. Egyptian Goddess, 543 F.3d at 678 (citations omitted). Though recall that for design patents “the concepts of literal infringement and equivalents infringement are intertwined.” Pac. Coast Marine Windshields, 739 F.3d at 700-01.
Against that backdrop, the question of potential negative limitations can arise in the context of whether logos (or the like) present on the accused product can or should be considered when comparing it to the design patent claim to determine if there is infringement.
It is necessary to compare the claimed design (as construed) as a whole to accused product. Ethicon Endo‐Surgery, 796 F.3d at 1335; Crocs, 598 F.3d at 1302-06. This is to say that in the “ordinary observer” analysis, the patented design is viewed in its entirety, as it is claimed. L.A. Gear, Inc. v. Thom McAn Shoe Co., 988 F.2d 1117, 1125 (Fed. Cir. 1993). “[A]ll of the ornamental features illustrated in the figures must be considered in evaluating design patent infringement.” Contessa Food Prods., 282 F.3d at 1378. “A patented design is defined by the drawings in the patent, not just by one feature of the claimed design.” KeyStone Retaining Wall Sys., 997 F.2d at 1450. This means the comparison of the claimed design (as construed) to the accused product must generally include all of the patent figures in comparison, and it cannot merely compare separate elements in isolation or involve serial element-by-element comparison.
Yet an infringement analysis that recites significant differences between the ornamental features of the claimed and accused designs is still acceptable if, in determining infringement, that analysis still mainly focuses on whether an ordinary observer would be deceived into thinking that the accused product’s design was the same as the patented design. Richardson v. Stanley Works, Inc., 597 F.3d 1288, 1295-96 (Fed. Cir. 2010). It is in that sense that negative limitations can be used to help articulate significant differences from the standpoint of an ordinary observer.
Along those lines, the Federal Circuit has held that the finder of fact can consider “an ornamental logo, its placement, and its appearance as one among other potential differences between a patented design and an accused one.” Columbia Sportswear N. Am., Inc. v. Seirus Innovative Accessories, Inc., 942 F.3d 1119, 1131 (Fed. Cir. 2019). In a subsequent August 2021 trial under that guidance, a jury found no infringement. Columbia Sportswear N. Am., Inc. v. Seirus Innovative Accessories, Inc., No. 3:17-cv-01781 (S.D. Cal. Aug. 6, 2021) (jury verdict of non-infringement). The parties subsequently cross appealed.
In Columbia, the patent owner sometimes made a comparison of only a selected portion of the claimed design to the accused product in briefing. This had the effect of broadening the asserted claim. For instance, in the first comparative example below for district court summary judgment briefing, note how the claimed design uses broken lines in FIG. 1 to show that a boundary exists but is unclaimed (seeMPEP § 1503.02(III) (9th Ed., Rev. 10.2019, June 2020)). But the claimed design of FIG. 1 includes a generally sinusoidal wave pattern with four full crests and five full troughs that appear uninterrupted between the broken line boundaries; whereas in a comparison table used in briefing only part of the claim with merely three full (and uninterrupted) crests and troughs was reproduced as allegedly being the “Patented Design”. And in the second example below, from appellate briefing, note how FIG. 2 is used by the patentee for comparison despite the asserted design patent stating that “FIG. 2 is an enlarged elevational view thereof, taken from any area in the design” (that is, FIG. 2 merely shows an enlargement of a portion [with]in the claimed design but does not show the entire claimed design). If we analogize this to the utility patent context, it is like comparing a selected claim limitation to the accused product in isolation without addressing one or more additional limitations present in the claim. The significance of the accused product’s interruption (with repeating logos) in comparison to the claimed uninterrupted design was a key issue in the case including its appeals. So the question of what constitutes the full scope of the claimed design is foundational to what is or is not interrupted in the accused product.
FIG. 1 of U.S. Des. Pat. No. D657,093 (left) and Portion of Plaintiff Columbia’s March 7, 2016 Motion for Partial Summary Judgment (right)Portion of U.S. Des. Pat. No. D657,093 (left) and Portion of Plaintiff Columbia’s September 18, 2018 Appellate Response and Reply Brief Showing FIG. 2 of U.S. Des. Pat. No. D657,093 Overlaid on Photo of Accused Product (right)
The district court declined to construe the design patent claim with a detailed verbal description in its Markman order, or to provide any other construction or guidance about design patent conventions, but instead later provided jury instructions that stated:
“A design patent’s claim defines what is covered by the patent. The claim is typically represented by illustrations. It is permissible to illustrate more than one embodiment of a design in a single design patent application. Each design patent contains multiple drawings to illustrate the claimed design.
The scope of the claim encompasses the design’s visual appearance as a whole. It does not cover a general design concept and is not limited to isolated features of the drawings. An inventor’s subjective intent is not relevant to the scope of the claimed design”
Quote from Jury Instruction No. 9 (as filed Aug. 6, 2021)
That jury instruction (No. 9) was largely generic. It could have been issued in any design patent case without changing a word. Neither the jury instruction nor the Markman order specifically addressed the proper interpretation of the language describing FIG. 2 quoted above, which is part of the claim. Most significantly, the jury was not instructed to disregard the presence of logos on the accused product (as Columbia had sought). But, additionally, the jury was not instructed about whether the asserted design patent actually included multiple embodiments or whether certain drawings showed the same design or merely incomplete portions of it. That meant that, in the Columbia case, there was no express “negative limitation” claim construction. Instead, everything came down to the comparison of the overall appearances.
“To determine infringement of a design patent, you must compare the overall appearances of the accused design to the Design Patent. The accused design is Seirus’s HeatWave fabric. If you find by a preponderance of the evidence that the overall appearance of the accused design is substantially the same as the overall appearance of the Design Patent, you must find that the accused design infringed the Design Patent.
Two designs are substantially the same if, in the eye of an ordinary observer, giving such attention as a purchaser usually gives, the resemblance between the two designs is such as to deceive an ordinary observer, inducing him to purchase one supposing it to be the other. You do not need, however, to find that any purchasers were actually deceived or confused by the appearance of the accused products. You should consider any perceived similarities or differences between the patented and accused designs. Minor differences should not prevent a finding of infringement.”
Quote from Jury Instruction No. 10 (as filed Aug. 6, 2021)
The jury instruction (No. 10) regarding the comparison step did mention the accused product by name. But otherwise that instruction is also fairly generic. Jury instructions nos. 11-13 also pertained to design-patent-specific issues, including comments about the proper use of prior art in instruction no. 11.
The district court could have provided further claim construction guidance. But it chose not to. As already noted, the jury held that the patented design was not infringed. On the next appeal, there will surely be a dispute over the ultimate verdict of non-infringement of the design patent, but also perhaps about the mostly generic jury instructions related to design patent claim construction and infringement analysis and how those impact any “negative limitations” in the design patent claim. Though, interestingly, at the district court neither party really argued this point regarding the proposed final jury instructions for the August 2021 trial (most of the arguments over those instructions instead centered around what could be ignored, proper consideration of marketing materials evidence, how functionality should be referenced if at all, and the relevance and proper role of alleged prior art).
Conclusion
The appropriate way to address “negative limitations” in design patent claims is: first, to address in claim construction any prosecution history disclaimer or prosecution history estoppel issues that might give rise to recapture issues around such “negative limitations”, as well as any relevant interpretations of the text of the claim (including the title and description) that might do the same; and, second, to articulate the way design features affirmatively present in the accused design represent significant differences from such “negative limitations” in the claimed design in an analysis that still mainly focuses on whether an ordinary observer would be deceived into thinking that the accused product’s design was the same as the patented design overall.
The first aspect might not be relevant in all cases. Those questions will be highly dependent on the content of the asserted design patent claim and the prosecution history. But the second aspect could potentially apply whenever the asserted design patent appears to recite, in part, a “negative limitation”. This second part might impact jury instructions, as well as the way a case is argued to the finder of fact. It could also impact a pre-suit opinion of counsel analysis. Both factors might come up as part of dismissal, summary judgment, judgment on the pleadings, and/or JMOL motions, as well as in appeals.
January 2022
Austen Zuege is an attorney at law and registered U.S. patent attorney in Minneapolis whose practice encompasses patents, trademarks, copyrights, domain name cybersquatting, IP agreements and licensing, freedom-to-operate studies, client counseling, and IP litigation. If you have patent, trademark, or other IP issues, he can help.
It may be desired to proactively challenge the validity or patentability of a granted U.S. patent for a variety of reasons. What are the available options to challenge a granted patent either at the U.S. Patent & Trademark Office (USPTO) or in court? The following table compares the different types of proceedings and summarizes the applicable standards.
Anyone with standing (substantial controversy between parties having adverse legal interests of sufficient immediacy and reality; requires affirmative act by patentee)
Austen Zuege is an attorney at law and registered U.S. patent attorney in Minneapolis whose practice encompasses patents, trademarks, copyrights, domain name cybersquatting, IP agreements and licensing, freedom-to-operate studies, client counseling, and IP litigation. If you have patent, trademark, or other IP issues, he can help.
