Categories
Patents Q&A

Does Your Patent Allow for Infringement Detection?

Patent law places the burden on the patentee to identify infringement and enforce the patent against infringers. This raises an important gating question. How can patent infringement be detected? Some patents—and more specifically some patent claims—can make detection of infringement either easier or more difficult. What follows are some important considerations about patent infringement detection, and a possible alternative to patenting for hard-to-detect inventions.

Proving Infringement

A patent establishes exclusive rights in an invention that provide a limited monopoly to the patentee. The claim(s) of a patent determine the scope of what is patented, and by implication what is not patented. There are different types of infringement possible under U.S. patent law. Each type has its own elements that must be proven.

Generally speaking, direct patent infringement in the U.S. requires that each and every element or limitation—as properly construed—of at least one claim of a patent is found either literally or (sometimes) equivalently in an accused product or method. The infringement analysis always involves comparing the asserted patent claim(s) to an accused product or method. Importantly, a patent only covers what is claimed. So the comparison for an infringement analysis always depends on what is (or is not) claimed. And literal infringement requires meeting each element of the claim exactly. Any deviation from a claim limitation (as properly construed) will preclude a finding of literal infringement.

Example Comparison for Infringement Analysis

The following illustration helps explain how patent claims are compared to a potentially infringing product (or process). This example is highly simplified and assumes that the hypothetical claim has no negative limitations and no closed or partially-closed transitional phrases following the preamble, and that no Doctrine of Equivalents issues arise.

graphic comparing claim elements A, B and C to an accused product with elements, A, B, Y, and C, with the respective elements A, B, and C connected by arrows, that is infringing

In the simplified example graphic above, a claim with elements A, B, and C is compared to an accused product. Here, the accused product contains each claim element A, B, and C. The accused product meets all the limitations of the claim, so there is infringement. Ordinarily, the presence of an additional element Y in the accused product does not change this result. The accused product does not have to be identical to embodiments disclosed in the patent. It only matters that the accused product falls within the scope of the given claim by meeting all of the claim limitations.

Alleging Infringement

In order to bring a lawsuit for infringement, there must be a reasonable basis to believe that infringement has occurred. Federal Rule of Civil Procedure 11 requires “an inquiry reasonable under the circumstances” before commencing a lawsuit. This encompasses both legal and factual aspects and bars complaints made for improper purposes (such as to harass). Courts can issue sanctions on attorneys, law firms, and parties for violations of this rule.

Courts have said that in patent cases Rule 11 requires, at a minimum, interpreting the asserted patent claim(s) in a non-frivolous manner and comparing the accused device with those claims before alleging infringement. See Q-Pharma, Inc. v. Andrew Jergens Co., 360 F.3d 1295, 1300-03 (Fed. Cir. 2004).

“In bringing a claim of infringement, the patent holder, if challenged, must be prepared to demonstrate to both the court and the alleged infringer exactly why it believed before filing the claim that it had a reasonable chance of proving infringement. Failure to do so should ordinarily result in the district court expressing its broad discretion in favor of Rule 11 sanctions . . . .”

View Eng’g, Inc. v. Robotic Vision Sys., Inc., 208 F.3d 981, 986 (Fed. Cir. 2000)

So it is not permitted to simply wildly guess or casually speculate that an accused product meets all the limitations of a patent claim. But applicable rules means that judges ultimately decide what is reasonable or non-frivolous under the circumstances.

Detectability

Establishing infringement means proving that all the elements of an asserted claim are present. And bringing a lawsuit in the first place requires reasonable confidence you will prevail. But what if you can’t tell exactly how a potentially infringing product is configured or how it was made or operates during use? For instance, what if there are inaccessible internal components, the composition of certain materials cannot be tested, manufacturing methods are not apparent from resulting physical characteristics, or the performance of certain software-based computer processing steps is unclear? Or what if a method of use requires that an end user operate a device but it is unknown if or when that has happened? These are all problems with detecting infringement.

The crux of the detectability issue is that you need to have a level of information about potentially infringing products commensurate with the level of detail recited in the claim(s) of a patent. Investigations to locate that information can range from the simple to the complex and expensive to the impossible. Sometimes merely reviewing marketing materials for competing products is insufficient to understand if claimed elements are present or not. Then it may be necessary to obtain one of the products for evaluation, or look for some other source of the missing information.

Example Detectability Problems

In the simplified example graphic immediately below, another accused product is compared to the claim with elements A, B, and C. This accused product meets claim element A and B. However, it is unclear whether claim element C is found in the accused product or not. This is a detectability problem. Whether infringement has occurred or not here is not yet known because it has not yet been established that the accused product falls within the claim. More information about the accused product is required to make a final determination.

graphic comparing claim elements A, B and C to an accused product with elements, A, B, and an unknown "?", with the elements A and B connected by arrows and an arrow pointing to the question mark, that presents a detectability problem

Take as another example a patented software-driven device that produces a particular result based on a certain type of calculation (following a specific algorithm). If it is possible for competing products to achieve the same result using different calculations, then it may be hard to detect infringement. It may not even be possible to reverse-engineer how particular software commands are written. In this situation, detection of infringement may be difficult even if all the physical hardware components are the same.

Yet another example involves a claim to a chemical with a particular molecular structure. You must have the means to test for the presence of that molecular structure to detect infringement. This might necessitate obtaining product samples and sending them to a lab for analysis.

Patentability and Detection

Ideally patent claims will only recite elements that are easily detected through convenient forms inspection or testing of an accused product. This aids with enforcement of the patent. During patent preparation and prosecution, care should be taken to write claims that recite what is detectable rather than what is not. Although, this is sometimes more easily said than done.

Before enforcing a patent you first have to obtain a patent. This means convincing at least one patent examiner that the claimed invention is patentable. The broader the claim, the more difficult it can be to establish patentability. It is fairly easy to want broad claims. What patentee wouldn’t want wider coverage? But you can’t always get what you want. Sometimes difficult- or impossible-to-detect elements are precisely what make inventions patentable over the prior art. Without them, the claims may be rejected as unpatentable. In those situations, the choice may be between claims that make it hard to detect infringement or having no patent at all.

Trade Secrecy as an Alternative to Patenting

There is an alternative to patenting. And that is trade secrecy. Of course, not all inventions lend themselves to being kept secret. But an invention that is not detectable in physical products, or only involves steps performed away from public view, may be a good candidate for trade secrecy. An example is a manufacturing method, or a machine, tool, or fixture used in manufacturing. These sorts of things can often be keep secret inside a private factory. Another example is a “secret formula” for a chemical composition that cannot be reverse-engineered through testing. So an inventor may have a choice between either pursuing a patent or instead maintaining a non-detectable invention as a trade secret.

An important consideration when relying on secrecy is the level of confidence you can have that it is practical to do so. Trade secret protections are lost when something is publicly disclosed. So foregoing patent protection means thinking long and hard about what steps can be taken to maintain secrecy and how effective those steps are likely to be.

Photo of Austen Zuege

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.

Categories
Patents Q&A Trademarks

What Is the Federal Circuit?

In the field of U.S. intellectual property (IP) law, there are often references to the Federal Circuit. What is the Federal Circuit? This brief article will explain it.

Overview

The United States Court of Appeals for the Federal Circuit, or “Federal Circuit” for short, is a U.S. Federal appeals court. It hears cases appealed from various places including U.S. federal district courts and certain Federal agencies including the U.S. Patent & Trademark Office (USPTO) and the International Trade Commission (ITC). It was created in 1982. It replaced and merged the prior U.S. Court of Customs and Patent Appeals and the appellate division of the U.S. Court of Claims, which no longer exist.

Jurisdiction

What makes the Federal Circuit rather unique is that it has exclusive subject matter jurisdiction for certain types of cases. (28 U.S.C. § 1295). In general, appeals in Federal cases are made to regional circuit courts. That is, federal appeals courts are mostly divided into geographic “circuits”. They hear appeals from lower (district) courts within their respective geographic areas. But, instead, the Federal Circuit hears appeals from any district court in the country relating to patents and certain other matters, as well as appeals from certain executive branch agencies.

Map of geographic boundaries of U.S. courts of appeals (and U.S. district courts)
tree graphic illustrating Federal Circuit jurisdiction

In particular, the Federal Circuit has exclusive appellate jurisdiction over all U.S. federal cases involving patents, plant variety protection, trademark registrations, government contracts, veterans’ benefits, public safety officers’ benefits, federal employees’ benefits, and various other types of cases. Appeals involving Trademark Trial & Appeal Board (TTAB) and Patent Trial & Appeal Board (PTAB) decisions and patent and trademark prosecution (that is, cases related to the examination and granting of patents and trademark registrations) all go to the Federal Circuit. There are some exceptions, however. Cases involving assignments of patents may go to a regional circuit court instead. Trademark infringement matters are appealed from district courts to regional circuits, not to the Federal Circuit.

Conclusion

Because of the number of patent and trademark cases it hears, and its exclusive jurisdiction over cases involving U.S. patent laws, the Federal Circuit is important to know about in order to understand IP law in the United States. Federal Circuit opinions and orders (i.e., decisions in individual cases) can be found here, or via proprietary case reporter publications and databases.

Photo of Austen Zuege

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.

Categories
Patents Q&A

What Are Claims in a Patent?

Patents and patent applications typically have one or more “claims”. But what are claims? What is the significance of claims in patent law? This article offers a brief explanation of what they are and why they matter. It also explains some common misunderstandings and misconceptions about patent claims that can lead to great confusion.

Purpose of Claims

Patents provide exclusive rights in the form of a limited monopoly to an invention. Claims define the scope of exclusive legal rights in a granted patent or, in the case of a patent application, the scope of exclusive rights being sought. In other words, when thinking of patents as being premised on a quid pro quo, claims define the boundaries of the exclusive rights granted by a government to the patentee in exchange for disclosing an invention.

A common way to explain patent rights is to analogize them to real property (that is, land ownership). The claims are what establish the boundaries or metes-and-bounds of legal rights to a given patented invention. So claims are a bit like lot lines that establish the perimeter of a plot of land. Anything falling within the scope of a claim is protected. Just like the area within lot line boundaries belongs to the landowner.

Consider this simple guideline for granted patents: anything claimed is patented, and anything not claimed is not patented. In that sense, claims put others on notice of the scope of exclusive rights held by a patentee. And, when a new patent application is filed, the claims are the main focus of examination to determine if the invention (as claimed) is patentable. A patent is only being sought for what the claims of a given application recite.

Under U.S. patent law, claims are considered a part of the “specification” of a patent application. The basic requirements for claims are set forth in Section 112 of those patent statutes:

“The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.”

35 U.S.C. § 112(b)

When the U.S. patent laws set out what constitutes infringement of a “patented invention” (35 U.S.C. § 271). This is a reference to the claims. That is because the claims are what define the scope of the patented invention.

However, patent laws may differ between countries. For instance, the USA follows what is called peripheral claiming. Peripheral claims set forth the outermost boundaries of the exclusive rights with reasonable clarity, and anything outside the claims is generally not protected (with a rare exception under the doctrine of equivalents). But some other countries follow central claiming instead. Under central claiming regimes, the claims set out a basic inventive concept and the exclusive patent rights encompass an area that might extend beyond the literal scope of the claim language based upon the inventor(s)’s contribution over the prior art (as later determined by a court). Peripheral claiming makes the scope of rights more certain prior to an infringement lawsuit.

Content

What claims say and how they say it varies. They are unique to each application or patent. They are also written by patent applications, who have considerable discretion over what they recite and how they are formulated. Claims are meant to define inventions, so they necessarily vary to reflect the particular subject matter of a given invention. But any given claim might define an invention broadly or narrowly in scope, relatively speaking.

In order for a patent application to be found patentable, its claims have to meet the requirements for patentability. Among other things, this means that the claims must distinguish the invention over the prior art. Accordingly, claims of a given application may try to distinguish the prior art by reciting elements (also called limitations) that go beyond what was already known.

Claims can be—and often are—amended, and may between an original application, a pre-grant published application, and/or a later-granted patent. Claims might also be canceled/deleted or new claims added during examination (which is also called “prosecution”). There are even procedures to amend or correct claims after a patent has issued. This means that the substantive content of the claims can change over time. Sometimes this means that a given claim is narrowed by amendment to establish patentability. This can give rise to prosecution history estoppel.

The interpretation or construction of terms in a patent claim is very important. For instance, certain terms of art may have special legal or technical meaning. The way claims are interpreted can vary greatly between different jurisdictions.

Format

The format in which claims are written follow some general guidelines, even if their substantive content varies. For instance, they always appear at the very end of U.S. patents. They are each written as a single sentence. Parts of a claim may start on separate lines with special indenting to highlight distinct clauses. Although any given clause might contain multiple discrete limitations or elements. It is common for claims to use words like “wherein” and “comprising” that are not often used in everyday speech.

Means-plus-function (or step-plus-function) limitations are also a special type of claiming format permitted in the USA (35 U.S.C. § 112(f)). These limitations are interpreted to cover corresponding structures, materials, or acts disclosed elsewhere in the patent or application (and their known equivalents). Understanding when means-plus-function claiming is invoked or applies, and how to properly interpret the scope of that limitation, is sometimes difficult. But one rule is clear. There can be no “single means” claims, because a claim that contains only a single limitation in means-plus-function format would be an impermissible central claim rather than a peripheral claim.

A patent may have only one, a few, or very many claims. Typically, each claim is separately numbered. Some claims may refer back to prior claims by number. However, U.S. design patents have only a single unnumbered claim. U.S. plant patents also have only a single claim but it is numbered. Regardless of how many are present, each claim is generally considered separately. In this respect, claim numbering helps indicate how many different definitions of a given invention must be considered when evaluating either patentability/validity or infringement.

Types of Claims

Independent Claims vs. Dependent Claims

Claims can be either independent or dependent (35 U.S.C. § 112(c)). An independent claim stands on its own. In contrast, a dependent claim refers back to a prior claim (by number) and incorporates the limitations of all base claims (35 U.S.C. § 112(d)). The status of a given claim as either independent or dependent can have important legal significance for patentability/validity and other analyses.

The following is an example of a set of four claims in which claims 1 and 4 are independent claims and claims 2 and 3 are dependent claims:

1. An apparatus comprising an element A, an element B, and an element C.
2. The apparatus of claim 1, wherein the element A and the element B are each made of metal.
3. The apparatus of claim 2, wherein the element A is welded to the element B.
4. A method comprising step X, step Y, and step Z.

In the example above, claim 2 depends from claim 1. Because of that dependency, claim 2 incorporates all of the elements or limitations of independent base claim 1 and further adds an additional limitation. Claim 3 depends from claim 2, which in turn depends from claim 1. This means claim 3 incorporates all of the limitations of both base claims 1 and 2 and further adds an additional limitation. Claim 4 is another independent claim, which stands on its own. The limitations of claims 1-3 are not incorporated into claim 4.

Claim 1 of any patent or patent application is always an independent claim, because there is no prior claim to refer back to. Any claims that follow claim 1 might also be independent, or might be dependent. This depends on how they are written. Patentees have considerable latitude over how many claims and what types of claims are present. Although dependent claims are not permitted in U.S. design or plant patents.

When analyzing patents and patent applications, independent claims usually always require consideration, while dependent claims might not in some situations. For example, when assessing potential infringement, a dependent claim can only be infringed if its independent base claim is also infringed. But an independent claim might be infringed even if no dependent claim is infringed. So, in many contexts, dependent claims can be thought of as reciting optional features. Yet dependent claims might still be important. Validity and patentability are assessed on a claim-by-claim basis, so while an independent claim might be unpatentable (or invalid), dependent claims depending from it might still be patentable (or valid).

Multiple Dependent Claims

Multiple dependent claims are also possible (35 U.S.C. § 112(e)). A multiple dependent claim refers back to multiple prior claims in the alternative. Examples of multiple dependent claim references are “the method of any preceding claim” or “the apparatus of claim 1 or 2” or “the system of any of claims 2, 4, and 8.” The easiest way to think about multiple dependent claims is that they always present a single claim that is equivalent to having a number of separate dependent claims that each depend from different base claims.

Omnibus Claims

An omnibus claim makes a general incorporation into a claim of some other disclosure, without specifically defining the invention or even a central inventive concept. An example is “The apparatus substantially as shown and described.” Omnibus claims are permitted in some jurisdictions, but not in U.S. utility patents. Except U.S. design patents always have only a single omnibus claim reciting the design “as shown and described” (37 C.F.R. § 1.153(a)). And U.S. plant patents always have a single claim in omnibus format that states “as described and illustrated” (37 C.F.R. § 1.164)—although plant patents cover only asexual reproduction of the patented plant, through grafting, cuttings, etc., which distinguishes their claims from true omnibus claims in terms of their effect.

Other Types

There are a number of other names given to certain types of claims, often more informally. For instance, Jepson claims specifically identify the point of novelty (in a manner called two-part form in many jurisdictions), combination claims recite a particular combination of components, a Beauregard claim recites a computer-readable medium on which computer program instructions are encoded, product-by-process claims recite an apparatus in terms of how it is made, etc.

Difference Between Claims and Other Disclosures

One of the most important things to understand is that the claims of a given patent—and not other parts of a patent like the detailed description or drawings— define exclusive rights to a patented invention. As already mentioned, what is claimed is patented and what is not claimed is not patented. This means it is possible to have unclaimed disclosures in a given patent. For instance, a patent might include a drawing illustrating a prior art device but not claim it. In other cases, a patent might claim only one or a few particular embodiments or “species” of an invention and not a generic invention (or entire “genus”).

When trying to understand if their is risk of infringing someone else’s patent, a mistake frequently made by people unfamiliar with patent law is to look at the drawings or some other text in the specification (like the detailed description section) and assume that any and all such disclosures are “patented”. That is incorrect. Only the claims define the patented invention. There are many reasons why there might be unclaimed subject mater disclosed in a patent—including a patent office determining that some aspects were or are not patentable. But often those reasons are unimportant. It is the claims, as properly construed, that define the scope of the patentee’s exclusive rights.

In contrast, if a given prior art patent or published patent application is cited as prior art, it usually makes no difference whether the relevant prior art teachings were claimed or not. Most of the time the claims are irrelevant to the value of a given reference as prior art—with some exceptions for situations like double patenting.

Photo of Austen Zuege

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.

Categories
Articles Patents

Patent Marking Program

Materials from a presentation by Austen Zuege about patent marking in the United States are available here:

“Patent Marking: Legal Standards and Practical Issues”

These downloadable materials from a past live presentation address basic marking requirements and best practices for patent marking, as well as requirements for virtual marking, alternative marking on a label or package, ways the sufficiency of marking can be challenged, and false marking. These materials cover the ins and outs of patent marking in a format packed with real-world examples.

Marking is simple enough in concept but there are a surprising number of nuances and practical challenges for implementation. Also, the America Invents Act (AIA) reshaped numerous aspects of marking that continue to reverberate. For instance, virtual marking was introduced with the AIA and there is now a growing body of court decisions clarifying what kinds of virtual marking practices are sufficient and what kinds are not. These practical aspects of marking are addressed in these program materials.

More information about patent marking is available in this detailed guide and this brief overview.

Photo of Austen Zuege

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.

Categories
Patents Q&A

How Can I Calculate Patent Term?

Patents have a maximum term and cannot be renewed. This is part of the quid pro quo underlying modern patent law. The patentee gets exclusive rights for a limited time but then the technology disclosed in expired patents can be freely used by the public (in at least the jurisdiction that issued the patent). Knowing how to calculate patent term is therefore important in order to determine when a given patent has expired. But, for better or worse, the term of any given patent can vary. There is no single fixed term for all U.S. patents. And the applicable term is not always apparent on the face of a given patent. So how is patent term calculated for U.S. patents?

USPTO Patent Term Calculator

One of the simplest and most practical ways to determine the term of a given U.S. patent is to utilize a patent term calculator provided by the U.S. Patent & Trademark Office (USPTO). Using this downloadable spreadsheet requires inputting certain information about a given patent. Only some of the necessary information appears printed on a granted patent. Other information must be researched in USPTO records, mainly through Patent Center.

The advantage of the USPTO’s patent term calculator is that it can be used by anyone, even people who do not understand the applicable patent laws. However, it still requires ascertaining the correct information to enter in the spreadsheet. That requires knowing where to find such information. The patent term calculator also requires a level of confidence that the correct information is being entered. That is, it still requires knowing some of the terminology so that correct, relevant information is entered.

Read on for more information about the sorts of information relevant to proper patent term calculations.

Relevant Factors

What follows is a more detailed explanation of factors that determine the enforceable term of a given patent. These factors include factors that influence how to calculate a given patent’s term, as well as things that might cut short the enforceable term of a given patent. In any given instance, consulting with a knowledgeable patent attorney is recommend to determine the correct term of any given U.S. patent.

Type of Patent

Paten term first of all depends on the type of patent involved.

U.S. utility and plant patents have a basic term of 20 years from the relevant filing date (35 U.S.C. § 154)—there being some nuance about which filing date is used here.

timeline graphic of basic 20-year patent term
Timeline Showing Basic Patent Term for U.S. Utility and Plant Patents (Including PCT National Phase Entries)

A priority claim to a foreign patent application (stemming from the Paris Convention or a PCT application that did not designate the USA) or to a prior U.S. provisional patent application does not count against the term (35 U.S.C. § 154(a)(3)). This means a foreign priority or prior provisional filing can effectively extend patent term.

timeline graphic for basic patent term involving provisional or foreign priority
Timeline Showing Basic Patent Term for U.S. Utility and Plant Patents Based on a Prior U.S. Provisional or Foreign Priority Application

For regular PCT national phase entries to the USA, the PCT international filing date is used for term calculation (not the date of later U.S. national phase entry). That is, a PCT international application designating the United States is treated as a U.S. application (see 35 U.S.C. §§ 372 and 375), with the national phase being just a different phase of the same application. So an ordinary national phase entry into the United States does not, by itself, involve a “priority” claim–although there may additionally be a priority claim involved.

The so-called domestic benefit of a prior U.S. non-provisional application (that is, for a continuation, continuation-in-part, or divisional application under 35 U.S.C. §§ 120, 121, 365(c), or 386(c), including PCT “bypass” applications) does count against patent term, so the term calculation should be based on the earliest such prior filing date. In other words, continuing applications that have priority/domestic benefit of a prior U.S. non-provisional application will have a reduced patent term. The related U.S. application data field (INID code 63) on the face of a patent, if present, can indicate an earlier filing date that may impact term.

timeline graphic of basic patent term involving domestic benefit claim in continuing application
Timeline Showing Basic Patent Term for Continuing U.S. Utility and Plant Patents Based on a Prior Domestic U.S. Application (Including PCT “Bypass” Applications)
Excerpt of U.S. Pat. No. 11,102,682 showing: "Related U.S. Application Data (63) Continuation of application No. 15/090,600, filed on Apr. 4, 2016, now Pat. No. 10,667,181"
Example of INID code 63 “Related U.S. Application Data” field on front page of U.S. Pat. No. 11,102,682, showing earliest filing date for patent term calculation of a continuing application

In contrast, U.S. design patents currently have a fixed basic term of 15-years from the date of grant (35 U.S.C. § 173). The filing date issues referenced above do not impact design patent term. This means that continuing design patents can potentially have later expiration dates, unlike with utility and plant patents.

timeline graphic of design patent term
Timeline Showing Basic Patent Term for U.S. Design Patents

Reissue patents are possible “for the unexpired part of the term of the original patent.” (35 U.S.C. § 251). This means that a reissue patent’s term is no longer than the term of the original patent, as subject to any extension or adjustment. It is possible that a reissue patent’s term could be shorter than that of the original patent (see discussion of terminal disclaimers below). But reissue does not lengthen patent term.

Filing Date and Changes in the Law

The laws around patent term have changed over time. Some patents applied for or granted prior to those changes in the law may be subject to a different term.

U.S. utility and plant patents applications filed before June 8, 1995 can have a term of 17 years from the date or grant rather than from the earliest applicable filing date. Any patent that was in force on June 8, 1995 will have a term that is the greater of the 20-year term as discussed above or 17 years from grant (35 U.S.C. § 154(c)).

For U.S. design patents, those issued from design applications filed before May 13, 2015 have a 14-year term from the date of grant (rather than 15-years from grant).

Of course, there may be future changes in the law that affect patent term calculations. And courts may issue decisions that affect the interpretation of laws that impact patent term calculations.

Patent Term Adjustment

Certain delays in examination can lead to an adjustment of patent term for a given original patent (but not for a reissue). This is called patent term adjustment (PTA) under 35 U.S.C. § 154(b). Normally, this PTA is calculated as the number of days beyond the basic 20-year term that the patent can remain in force. The PTA period normally appears on the face of each granted patent—typically in a “Notice” field denoted with an asterisk (*). The USPTO’s Patent Center portal also has a menu tab showing detailed PTA calculations for a given patent. However, it is possible for a patentee to challenge the USPTO’s PTA calculation in some circumstances, meaning the PTA period might be corrected later. PTA does not apply to design patents.

Excerpt of U.S. Pat. No. 10,000,000 showing: "(*) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 430 days."
Example of PTA notice on front page of U.S. Pat. No. 10,000,000, showing 430 days of additional patent term

Patent Term Extension

Patentees can potentially obtain patent term extension (PTE) under 35 U.S.C. § 156 based upon premarket regulatory review of certain human drugs, food or color additives, medical devices, animal drugs, and veterinary biological products. This restores some term lost while awaiting premarket government approval from a regulatory agency. An application for PTE must be submitted within sixty (60) days of when permission for commercial marketing or use occurred. Patentees have to affirmatively apply for PTE, which is not automatically granted. Also, PTE is only possible for patents on certain types of subject matter; it does not apply to design or plant patents. § 156 PTE is not indicated on granted patents and must be researched in USPTO records, mainly through Patent Center.

Disclaimers

A given patent may be subject to a disclaimer (35 U.S.C. § 253). The two types of disclaimers are a terminal disclaimer or a statutory disclaimer.

In a terminal disclaimer, the patentee disclaims or dedicates to the public a portion of the term of a given patent. That is, the term of the patent is shortened from what it might otherwise be. Terminal disclaimers are frequently used to overcome double patenting, by disclaiming the period of patent term (if any) that would extend beyond that of one or more other patents. They are also used when design patent applications are revived after abandonment, disclaiming a period of patent term equal to the period of abandonment. Terminal disclaimers do not affect § 156 PTE, however.

Excerpt of U.S. Pat. No. 11,102,682 showing the notice: "This patent is subject to a terminal disclaimer"
Example of terminal disclaimer notice on front page of U.S. Pat. No. 11,102,682
Excerpt of terminal disclaimer filed against U.S. Pat. No. 11,102,682
Excerpt from example terminal disclaimer filed against U.S. Pat. No. 11,102,682, disclaiming term beyond that of U.S. Pat. No. 10,667,181

The USPTO has sometimes, but not always, printed an indication that a given patent is subject to a terminal disclaimer on the front page of the patent. Terminal disclaimers can also arise after a patent has been granted. In any event, the duration (and possibly also the existence) of a terminal disclaimer must be researched in the prosecution history of the relevant patent in USPTO records. This can generally be done using the online Patent Center portal and viewing the “Documents & Transactions”. Although the calculation of the disclaimed period may require additional research and analysis. For instance, it may be necessary to calculate the term of one or more other patents or the period of applicant delay for a design patent.

For statutory disclaimers, one or more claims of a patent are effectively surrendered. This means that some claims may no longer be in force, even though other claims might.

Lapse or Expiration for Non-Payment of Maintenance Fees

In order to keep a given U.S. utility patent in force, periodic maintenance fees are required (35 U.S.C. § 41(b)). These are due by four, eight, and twelve years from the grant of the patent. However, there are no maintenance fees required for U.S. design patents or plant patents (37 C.F.R. § 1.362(b)).

If a maintenance fee is not paid on time, then the patent will lapse or expire. This means that a given utility patent might no longer be in force even though it has not yet reached its maximum possible term.

What makes lapses/expirations complicated is that the patentee may be able to reinstate (that is, revive) the patent if a maintenance fee payment deadline was missed unintentionally. This may give rise to intervening rights (35 U.S.C. § 41(c)(2)). So, significantly, the expiration or lapse of the U.S. patent due to a missed maintenance fee may not mean the final and absolute end of rights in that patent if late payment is accepted.

Terminology describing this lapses/expiration for non-payment of maintenance fees has varied. The USPTO currently tends to use “expiration” but “lapse” is a better term because it differentiates situations where revival is possible from those in which a patent’s term has expired permanently because it has reached its maximum limit.

Invalidation and Cancellation

Patents can be invalidated by courts or cancelled by the USPTO, usually as the result of a challenge by another entity. This can affect all or merely some claims of a patent. Such an adverse ruling (after exhaustion of all rights of appeal) can end or limit rights in the patent short of its maximum possible term. It is necessary to research the existence and status of such an adverse ruling, if any.

Withdrawn Patents

Lastly, some patent numbers have been withdrawn by the USPTO. These were essentially never really patents in the first place, for various reasons, and thus have no term. Although, to complicate matters, the USPTO has also reinstated some previously withdrawn patents.

Laws Vary by Jurisdiction

The discussion above pertains only to U.S. patents. In other countries, laws may differ regarding the calculation of patent term, the availability of supplementary protection certificates, and so on.

Photo of Austen Zuege

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.

Categories
Articles

Federal Circuit Columbia Decision Both Clarifies and Muddies the Proper Use of Comparison Prior Art

When can prior art be used to assess alleged infringement of a design patent?  This has been an evolving area of U.S. patent law.  The question matters because looking at only the asserted patent and the accused product might not allow an ordinary observer to understand the ways in which the patented design is similar (or dissimilar) from known designs. A recent court decision sheds some light on the issue while at the same time muddies the waters in light of past cases that reached seemingly different results.

When assessing design patent infringement, “when the claimed and accused designs are not plainly dissimilar, resolution of the question whether the ordinary observer would consider the two designs to be substantially the same will benefit from a comparison of the claimed and accused designs with the prior art. . . .” Egyptian Goddess, Inc. v. Swisa, Inc., 543 F.3d 665, 678 (Fed. Cir. 2008) (en banc).  This is essentially a three-way visual comparison, in which differences “that might not be noticeable in the abstract can become significant to the hypothetical ordinary observer . . . .” Id. This is not about validity/invalidity but rather about how prior art informs the comparison of the patented design and the accused product to determine if there is infringement or not.

A recent Federal Circuit decision addressed what sort of prior art can qualify as comparison art.  In the second appeal in an ongoing dispute, a Federal Circuit panel held that “to qualify as comparison prior art, the prior-art design must be applied to the article of manufacture identified in the claim.”  Columbia Sportswear N. Am., Inc. v. Seirus Innovative Accessories, Inc., Nos. 2021-2299 and 2021-2338, Slip Op. at *21-23 (Fed Cir. Sept. 15, 2023) (“Columbia II“).

 In reaching that conclusion, the Columbia II panel cited one Supreme Court case from the 1800s, plus Egyptian Goddess and further said that “[s]imilar examples abound”.  But do they really?  The Columbia decision cites only a single post-Egyptian Goddess precedential case that was not abrogated (ABC Corp. I v. P’ship & Unincorporated Ass’ns Identified on Schedule “A”, 52 F.4th 934 (Fed. Cir. 2022)), plus one non-precedential case (Wallace v. Ideavillage Prods. Corp., 640 F. App’x 970, 971, 975–76 (Fed. Cir. 2016) (nonprecedential)). 

Two other case citations in Columbia II rely on portions of opinions (Arminak & Assocs., Inc. v. Saint-Gobain Calmar, Inc., 501 F.3d 1314, 1318, 1324–25 (Fed. Cir. 2007) and Unidynamics Corp. v. Automatic Prods. Int’l, Ltd., 157 F.3d 1311, 1313, 1324 (Fed. Cir. 1998)) that dealt with the “point of novelty” analysis that was specifically overruled by Egyptian Goddess, Inc. v. Swisa, Inc., 543 F.3d 665, 678-79 (Fed. Cir. 2008) (en banc).  Columbia II’s citations do not include any identifications any portions of the cited cases that were abrograted, or otherwise explain why or how specific aspects of those point of novelty analyses were still valid and relevant—as was the case in Egyptian Goddess, there might still be similarities although the theoretical framework and thus the purpose of looking at the prior art is different.

Then in a lengthy footnote 8 the Columbia II panel attempts to explain away a prior precedential case that reached a seemingly contrary outcome, Lanard Toys Ltd. v. Dolgencorp LLC, 958 F.3d 1337 (Fed. Cir. 2020).  If an attorney submitted a brief written in such a manner, she would at a minimum probably be harshly scolded by the presiding judge(s), and at worst be sanctioned.  But apparently this Federal Circuit panel (Judges Prost, Reyna, and Hughes) has no qualms about doing this themselves.  It is possible to argue that the Columbia II decision, although designated as precedential by the panel, is actually non-precedential due to being in conflict with Lanard ToysSee Newell Cos., Inc. v. Kenney Mfg. Co., 864 F.2d 757, 765 (Fed. Cir. 1988) (when Fed. Cir. panel decisions are in conflict, the later one is non-precedential).

In any event, one issue that footnote 8 of Columbia II does not fully address is the question of comparison art when the claimed article is specifically a simulation, and to the extent that it does that footnote may not be controlling.  MPEP § 1504.01(d) (9th Ed., Rev. 07.2022, Feb. 2023) deals designs attempting to claim articles that are simulations of something else.  The Columbia case does not specifically address In re Wise, 340 F.2d 982, 144 USPQ 354 (CCPA 1965), which dealt with the use of something other than the same article as prior art to affirm a rejection of a claimed design.  There, the claimed design was a “promotional advertising souvenir”, whereas one of the prior art references was a mere “representation of a conventionalized teardrop.”  Id. at 982-83.  In particular, the claimed design showed a teardrop shape article that was hollow with transparent walls, within which appears a planar member shown in dotted lines, on which advertising matter is to be placed, and additional prior art was cited for the proposition that display devices inside of hollow transparent containers were known—the fact that the interior components were in broken lines meant that their specific content carried no patentable weight.  Id. at 983-84.  Partly the issue raised here is whether Wise was—or could be—abrogated by In re Surgisil, L.L.P., 14 F.4th 1380 (Fed. Cir. 2021), which did not specifically address Wise or a “simulation”-based rejection, or other seemingly contrary precedent like In re Glavas, 230 F.2d 447, 450 (CCPA 1956) (“the use to which an article is to be put has no bearing on its patentability as a design and that if the prior art discloses any article of substantially the same appearance as that of an applicant, it is immaterial what the use of such article is. Accordingly, so far as anticipation by a single prior art disclosure is concerned, there can be no question as to nonanalogous art in design cases”).  Surgisil overturned a patent office rejection premised on the title of the application not limiting the scope of the claim of a pending design application, where the applied-for design was titled a “lip implant” but the cited prior art having essentially an identical shape was for an artist’s “stump” blending/smudging tool.  That result in Surgisil stands in contrast to both Glavas, which said use and non-analagous art issues are irrelevant to patentability of designs, and Wise, which cited a mere representation of a teardrop that was not, specifically, a “promotional advertising souvenir” as claimed. 

Another way to look at this is to say that footnote 8 of Columbia II is mere dicta and not binding, because Columbia II did not deal with allegations that an asserted patented design was a “simulation”.  From that perspective, the footnote 8 discussion about waiver of arguments can be disregarded (the very fact that this discussion was placed in a footnote rather than in the main text provides some support for viewing it as mere dicta).  This is significant because the Columbia II panel could not overrule Lanard Toys, and neither the Columbia II panel nor the Surgisil panel could overrule Wise or GlavasSee South Corp. v. U.S., 690 F.2d 1368, 1369 (Fed. Cir. 1982) (“the holdings of . . . the United States Court of Customs and Patent Appeals, announced . . . before the close of business September 30, 1982, shall be binding as precedent in this court.”); Newell, 864 F.2d at 765.

The Columbia II panel argues that “using the same scope for anticipatory prior art and comparison prior art makes good practical sense.”  This is asserted without addressing the (“wise”) reasoning of the Wise decision, which set out contrary practicalities when an asserted design is alleged to be a simulation.  That is, Wise pointed out that a design may not be patentable if it merely simulates a known shape from another context, and a patentee cannot obtain exclusive rights by merely reproducing essentially generic representations—a concern that in many ways mirrors cases about utility patent eligibility where results are recited coupled with only generic or conventional computerization hardware.  Cf., e.g., Elec. Power Group, LLC v. Alstom SA, 830 F.3d 1350 (Fed. Cir. 2016) (claims were patent-ineligible abstract ideas because they did not require “use of anything but entirely conventional, generic technology.”). 

Other areas that remain somewhat unresolved pertain to partial claims, multi-part articles, and language reflecting intended use. For instance, if a design patent is for a “motorcycle with windscreen,” is prior art to a motorcycle alone (without a windscreen) available as comparison art, or prior art to a windscreen in isolation? Or a combination of both motorcycle and windshield comparison references? Does the answer depend at all on whether or not broken lines are used in the patent to make a partial claim? There a risk that design patents could gain inappropriate coverage over combinations of known (useful) elements in their functional capacity if and when the only available prior art shows merely some but not all of the components together in a single reference. And what about mere intended use language in the title of the patent? If the claim is to a “cat toy” and the prior art was expressly marketed as a “dog toy”, can the dog toy be used as comparison art, when both cats and dogs could actually play with either toy? Both instances involve a toy (and an animal toy no less), and differ only in the intended use by a different animal. There is older precedent stating that “the use to which an article is to be put has no bearing on its patentability as a design and that if the prior art discloses any article of substantially the same appearance as that of an applicant, it is immaterial what the use of such article is.” Glavas, 230 F.2d at 450.

These sorts of questions put added emphasis on the still-ambiguous role of claim construction in design patent litigation, as well as the need to carefully sect a title for a new design patent application. Parties to litigation now have added incentive to argue about claim construction in design patent cases, because the proper construction will determine not only the scope of the claim but also the availability of comparison prior art.

October 2023
Photo of Austen Zuege

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.

Categories
Articles

Virtual Patent Marking Program

Materials from a presentation by Austen Zuege, Grant Peters, and Bryan Wheelock about virtual patent marking are available here:

“Virtual Patent Marking: Practical Considerations, Recent Court Guidance, and Ideas for Designing Your Own Virtual Patent Marking Program”

This presentation and downloadable materials addresses basic requirements and best practices for virtual patent marking, as well as requirements for traditional/physical marking, alternative marking on a label or package, and false marking. Suggestions for implementing virtual patent marking are provided along with examples and hypotheticals used to discuss some of the practical challenges of virtual marking and where there continues to be areas uncertainty. More information about patent marking is available in this detailed guide and this brief overview.

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.

Categories
Articles

Willful Patent Infringement: Lingering Questions

A version of this article previously appeared in Landslide magazine (Vol. 14, Issue 4, June/July 2022), published by the ABA Intellectual Property Law Section.

Introduction

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.
Photo of Austen Zuege

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.


[i]. See, e.g., Brandon M. Reed, “Who Determines What Is Egregious? Judge or Jury: Enhanced Damages after Halo v. Pulse,” 34 Ga. St. U. L. Rev. 389, 393–96 (2018).

[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)).

[iv]. In re Seagate Tech., LLC, 497 F.3d 1360, 1371 (Fed. Cir. 2007) (en banc).

[v]. 35 U.S.C. § 298; see also Carson Optical Inc. v. eBay Inc., 202 F. Supp. 3d 247, 260–61 (E.D.N.Y. 2016) (§ 298 applies if the action is commenced on or after January 14, 2013); Halo Elecs., Inc. v. Pulse Elecs., Inc., 579 U.S. ___, ___, 136 S. Ct. 1923, 1936–37 (2016) (Breyer, J., concurring).

[vi]. Halo, 136 S. Ct. at 1933–34.

[vii]. Id. at 1933.

[viii]. Id. (citing Octane Fitness, LLC v. ICON Health & Fitness, Inc., 134 S. Ct. 1749, 1757 (2014)).

[ix]. Id.

[x]. Id. at 1932–35.

[xi]. E.g., WBIP, LLC v. Kohler Co., 829 F.3d 1317, 1341 (Fed. Cir. 2016); WesternGeco L.L.C. v. ION Geophysical Corp., 837 F.3d 1358, 1362 (Fed. Cir. 2016), reinstated, 913 F.3d 1067, 1075 (Fed. Cir. 2019); see also Halo, 136 S. Ct. at 1934–35.

[xii]. WBIP, 829 F.3d at 1341; Exmark Mfg. Co. v. Briggs & Stratton Power Prods. Grp., LLC, 879 F.3d 1332, 1353 (Fed. Cir. 2018) (“[T]he entire willfulness determination is to be decided by the jury.”); Eko Brands, LLC v. Adrian Rivera Maynez Enters., Inc., 946 F.3d 1367, 1377–79 (Fed. Cir. 2020).

[xiii]. WBIP, 829 F.3d at 1341; see also SRI Int’l, Inc. v. Cisco Sys., Inc., 930 F.3d 1295, 1310 n.6 (Fed. Cir. 2019) (when willfulness began is a factual issue).

[xiv]. Seventh Amendment questions remain regarding holdings that a jury cannot determine egregiousness of conduct. Compare WBIP, 829 F.3d at 1341 n.13, and Eko, 946 F.3d at 1378, with Halo, 136 S. Ct. at 1933 and n.*. See also United States v. Murdock, 290 U.S. 389, 394 (1933) (“willfulness” is a set of states of mind), overruled in part on other grounds by Murphy v. Waterfront Comm’n of N.Y. Harbor, 378 U.S. 52 (1964); Howard Wisnia & Thomas Jackman, “Reconsidering the Standard for Enhanced Damages in Patent Cases in View of Recent Guidance from the Supreme Court,” 31 Santa Clara High Tech. L.J. 461, 473–76 (2015). Yet punitive enhancement is a discretionary moral judgment, not a factual question. See Smith v. Wade, 461 U.S. 30, 52 (1983).

[xv]. Halo, 136 S. Ct. at 1933; Presidio Components, Inc. v. Am. Tech. Ceramics Corp., 875 F.3d 1369, 1382 (Fed. Cir. 2017).

[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. See SRI 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. See Schwendimann v. Arkwright Advanced Coating, Inc., No. 11-cv-820, slip. op. at 50 (D. Minn. July 30, 2018).

[xvii]. See, e.g., Bos. Sci. Corp. v. Nevro Corp., 415 F. Supp. 3d 482, 495 (D. Del. 2019).

[xviii]. Motiva Pats., LLC v. Sony Corp., 408 F. Supp. 3d 819, 837 (E.D. Tex. 2019) (citing Global-Tech Appliances, Inc. v. SEB S.A., 563 U.S. 754, 769 (2011)).

[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).

[xxi]. E.g., Charlotte Jacobsen et al., “Does Willful Blindness Beget Enhanced Patent Damages?,” Law360 (Feb. 28, 2020).

[xxii]. Nonend, 2016 WL 1253740, at *3; VLSI Tech. LLC v. Intel Corp., No. 18-cv-966, 2019 WL 1349468, at *2 (D. Del. Mar. 26, 2019); Ansell Healthcare Prods. LLC v. Reckitt Benckiser LLC, No. 15-cv-915, 2018 WL 620968, at *7 (D. Del. Jan. 30, 2018).

[xxiii]. Compare Vasudevan 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’”), and Maxell, 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), with SIMO 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), and Oxygenator Water Techs., Inc. v. Tennant Co., No. 20-cv-358, slip op. at 8–13 (D. Minn. Aug. 7, 2020), and SiOnyx, LLC v. Hamamatsu Photonics K.K., 330 F. Supp. 3d 574, 609 (D. Mass. 2018).

[xxiv]. See, 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 see Halo, 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.”).

[xxvi]. Read Corp. v. Portec, Inc., 970 F.2d 816, 827 (Fed. Cir. 1992), abrogated in part on other grounds by Markman v. Westview Instruments, Inc., 517 U.S. 370, 116 (1996).

[xxvii]. 35 U.S.C. § 298.

[xxviii]. Omega Pats., LLC v. CalAmp Corp., 920 F.3d 1337, 1353 (Fed. Cir. 2019); Ultratec, Inc. v. Sorenson Commc’ns, Inc., No. 13-cv-346, 2014 WL 4976596, at *2 (W.D. Wis. Oct. 3, 2014).

[xxix]. SRI Int’l, Inc. v. Cisco Sys., Inc., 930 F.3d 1295, 1309 (Fed. Cir. 2019); see also Halo, 136 S. Ct. at 1936–37.

[xxx]. See Cancer Rsch. Tech. Ltd. v. Barr Labs., Inc., 625 F.3d 724, 728–32 (Fed. Cir. 2010).

[xxxi]. Oil-Dri Corp. of Am. v. Nestle Purina Petcare Co., No. 15-C-1067, slip. op. at 5–6 (N.D. Ill. Mar. 8, 2019).

[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.

[xxxiii]. See supra note xxiv.

[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”).

[xxxv]. 35 U.S.C. § 298.

[xxxvi]. See SRI 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, with 35 U.S.C. § 298.

[xxxvii]. Visteon Glob. Techs., Inc. v. Garmin Int’l, Inc., No. 10-cv-10578, slip op. at 13–17, 2016 U.S. Dist. LEXIS 109564 (E.D. Mich. Aug. 18, 2016).

[xxxviii]. Compare id., with 35 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 also SIMO 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 also Schwendimann, 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 see SSL 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).

[xli]. Milwaukee Elec. Tool Corp. v. Snap-On Inc., 288 F. Supp. 3d 872, 886–88, 890–91 (E.D. Wis. 2017) (citing SSL, 769 F.3d at 1092).

[xlii]. Section 298 might only bar this evidence to initially prove willfulness but not its use in a subsequent enhancement determination.

Categories
Copyrights Patents Q&A Trade Secrets Trademarks

What Should I Do If Another Business is Infringing My IP?

An appropriate response to infringement (or misappropriation) will depend on which type(s) of intellectual property (IP) rights are involved.  While some forms of infringement can be enforced by the government, prosecutors rarely take up disputes between competitor businesses. This leaves it up to the IP owner to pursue a civil remedy. Therefore, the first step is generally to conduct your own investigation to ascertain your IP ownership rights, ascertain the identity of the infringing party or parties, preserve evidence of the infringement, and perform a legal analysis to confirm that the conduct in question is prohibited by law. Following an investigation, a cease & desist (demand) letter could be sent, a lawsuit initiated, or possibly other action taken.

Tip: Consider implementing a proactive monitoring program to search for and identify potential infringement of your IP. No one else will identify infringement for you.

As part of your initial investigation of infringement, the legal analysis should consider:

  1. do you have a chain of title to the IP (that is, can you prove ownership)?
  2. does the conduct fall within the scope of your enforceable exclusive rights or is the conduct permitted by law (such as a “fair use” under copyright law)?
  3. did the other party have permission? , perhaps impliedly
  4. what jurisdiction(s) is the infringer located in?
  5. what remedies are available for the type of infringement involved? 

Following an initial investigation, which should be performed with the assistance of a knowledgeable attorney, it is common to send a cease & desist or other demand letter.  This puts the infringer on notice of the claim of infringement, which can remove innocent infringer defenses going forward, trigger the accrual of damages, etc.  A letter might be sent to a publisher, distributor, web host, etc. as well, which can have significance under safe harbor provisions for some types of IP.  If a letter is ineffective, or simply not desired, litigation or certain non-litigation action should be considered. 

As to litigation, patent and copyright actions are handled exclusively by U.S. federal courts and generally require having a patent or copyright registration (at least for copyrightable United States works) before filing suit.  Trademark, trade secret, cybersquatting, and false advertising actions can sometimes be brought in either federal or state court.  A trademark registration is not required to bring suit in the U.S.  A statute of limitations or equitable limits may apply, such as a 3-year limit for copyright infringement claims and a 6-year limit on back damages for patent infringement. 

Remedies may be available outside of courts as well, though often without monetary recovery.  For example, administrative agencies such as Customs & Border Protection and the International Trade Commission can block or exclude importation of infringing goods, and a copyright small claims action may be available.  Online platforms and marketplaces may also have their own IP dispute resolution procedures and mandatory arbitration (e.g., UDRP, URS) may apply to domain name disputes. 

With some exceptions, many IP rights are generally enforceable on a jurisdictional or territorial basis.  If infringement implicates activities in another country, the available remedies and requirements to pursue a claim can vary widely and you may need to consult competent foreign legal counsel. 

Many IP disputes reach settlements, though it cannot be assumed that parties will be able to reach a pretrial settlement.  When considering bringing an infringement or misappropriation suit, bear in mind that awards of attorney’s fees are not always available or likely.  The cost to pursue an IP lawsuit might exceed the monetary recovery, though the benefits of stopping infringement or misappropriation may still be worth the unrecoverable expenses of a suit in some situations. 

Photo of Austen Zuege

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.

Categories
Patents Q&A

What is Prosecution History Estoppel?

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.

Photo of Austen Zuege

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.