Analogous Art for Design Patents

By Austen Zuege

The Federal Circuit issued an en banc decision in LKQ Corp. v. GM Global Tech. Operations LLC that substantially altered the obviousness analysis for design patents. The so-called RosenDurling framework was overruled (largely sidestepping the question of its abrogation by KSR). The patentability of ornamental designs of useful articles will now be under the same Graham v. John Deere obviousness standard that applies to utility patents. The LKQ decision emphasized that analogous arts requirements still apply to references cited for obviousness. But what will (or might) the analogous art requirements mean specifically in the design context? The following discussion explores some possibilities in a rough initial take on what might follow in the wake of LKQ.

Analogous and Non-Analogous Art: Two Tests or Prongs

In order to be used as a prior reference to try to establish obviousness, a given reference must be “analogous art”. There are two tests or prongs used to assess whether or not a given reference is analogous art (at least for utility patents). A reference is analogous art if: (a) it is from the same field of endeavor as the claimed invention (even if it addresses a different problem), or (b) if it is reasonably pertinent to the problem faced by the inventor (even if it is not in the same field of endeavor as the claimed invention). To be analogous, a given reference must satisfy only one of these two tests/prongs. Although the evidence and analysis may overlap, so some prior art might satisfy both tests.

The analogous arts framework has been around for a long time with respect to obviousness analyses for utility patents. Courts have generally taken a broad and expansive view of what constitutes analogous arts, especially in light of KSR. But it remains in place as a check against hindsight bias by establishing requirements for the factual foundation needed in order to rely on a given prior art reference for an obviousness argument. In that sense, it is about assessing whether a person of ordinary skill would have been motivated to look at or otherwise consider a reference at all in relation to the claimed invention at the time of invention (or effective filing date).

Analogous Art Analysis for Designs: Some Initial Thoughts

Although the LKQ decision paints its holding as something of a modification of the Rosen-Durling framework, that seems to be mainly a diplomatic attempt to counter the “chicken little” arguments that a disastrously chaotic free-for-all would ensue if design patents were held to the same standards as utility patents under KSR. Application of the non-analogous arts standard to designs going forward will likely not be merely a continuation of business-as-usual. LKQ represents a major shift in the patentability analysis for design patents. As a result, design patent prosecution will likely move further away from a quasi-registration process (a prospect that Robert Post once described as “intoxicating” applicants and their agents), with design examination extended beyond rejections for mere procedure and formality defects towards more substantive concerns. Obviousness rejections based on combinations of prior art references—long a ubiquitous feature of utility patent examination—should become more common. And similar effects should be seen in litigation and Patent Trial and Appeal Board (PTAB) challenges.

Yet the LKQ decision is hardly definitive about what will come next. For utility patents, the non-analogous arts test is rarely invoked and courts have generally taken a broad view of analogous art. But there are few if any prior cases applying analogous arts requirements to designs. That means there are many open questions and practical considerations about how it should be approached for designs. Let us turn to the two prongs/tests with those things in mind.

Analyzing the Same Field of Endeavor for Designs

The LKQ decision reaffirmed a statement from an old case that “[t]he scope of the prior art is not the universe of abstract design and artistic creativity, but designs of the same article of manufacture or of articles sufficiently similar that a person of ordinary skill would look to such articles for their designs.” Even though design patents are short, all design patents have to specify an article of manufacture. Indeed, U.S. Patent & Trademark Office regulations specify that “[t]he title of the design must designate the particular article.” (37 C.F.R. § 1.153(a)). So an applicant cannot obtain a design patent without specifying a particular article in the title, even if no further textual description is required.

What is notable here is that LKQ quotes a prior case that encompasses not only the same article of manufacture, but also “articles sufficiently similar that a person of ordinary skill would look to such articles for their designs.” This matters in view of a string of rather questionable Federal Circuit cases that took narrow views that only prior art for the same article of manufacture qualifies as prior art for validity analysis or for three-way infringement comparisons. I call these cases questionable in part because they contradict earlier precedent, but also because their conclusions are poorly explained or highly tendentious. So, a key takeaway is that in an en banc decision the Federal circuit has ruled that the analogous arts same field of endeavor prong/test must extend beyond the same article. This has the effect of neutralizing the impact of In re SurgiSil on the obviousness question (without yet resolving the conflict between SurgiSil and older precedent for anticipation).

As one example, LKQ may permit some generalizing of the article for the field of endeavor prong/test. This can be thought of as saying that the field of endeavor may be a genus of which the claimed invention is a species. For instance, if a particular design patent is for a plow of the sort used with a tractor in a farm or garden, the field of endeavor might be considered to be farm or tractor implements rather than only plows. That might mean that other implements like harrows used with tractors are analogous art. This could mean that a design that merely carries over the ornamental appearance of one farm implement to a different one is merely obvious, even though the implements serve different functions. Or, a prior art reference for a cat toy might be in the same or similar field of endeavor as a claimed dog toy. Different articles might also be similar, or part of the same genus, if they are known substitutes/alternatives.

But there might other ways to look at “similarity” for the field of endeavor prong/test for designs. Take an example of different articles sold together as a set or kit. There might be, for instance, a cutting board plus a large wooden fork and spoon that are sold together as a set, with common ornamentation on each item. This might be common surface ornamentation and/or a similar shape/configuration of handles of each item. Even though cutting boards and forks/spoons are different articles with different characteristics and uses, their sale together as a set may support a conclusion that they fall within similar fields of endeavor. Or there may be different articles advertised together as part of a product line with similar ornamentation, even if the articles are only sold separately. Such approaches to field of endeavor similarity are not entirely unlike the evaluation of the relatedness of different goods/services in trademark cases by looking at proffered evidence that they commonly emanate from a single source under a single brand.

Analyzing What is Reasonably Pertinent to the Problem Faced for Designs

LKQ recognized that a design patent itself does not clearly or reliably indicate the particular problem with which the inventor is involved. The decision further stated that it does not foreclose that art from outside the same field of endeavor could also be analogous. Apart from stating that this is a fact question to be addressed on a case-by-case basis, the court explicitly left this an open question. It will therefore be up to future cases to further develop the application of this standard. It will be interesting to see how this open question will eventually be resolved. What follows are some initial thoughts and suggestions, which draw from insight from social sciences.

Before going further, though, let me say that it is fair to wonder what problem-solving means for non-functional ornamental designs. This opens a rather large can of worms that is the question of whether industrial designs regarding ornamental appearance really involve “invention” at all. This is a big question because, in turn, it implicates the question of whether design patents, first made possible in the 1842 Patent Act following a proposal to have copyright protection for designs modeled on then-recent British law, are constitutional or not. Justice Douglas observed long ago that “attempts through the years to get a broader, looser conception of patents than the Constitution contemplates have been persistent.” Does that apply to the very existence of design patents? Although these concerns should be borne in mind, broader questions of constitutionality are for another day. Let us turn to the much narrower question of what designing really involves in terms of solutions it purports to offer.

Setting aside design patent protection pursued for improper purposes (such as to try to preclude functional interoperability), most industrial designs are about marketability. This is a topic Thorstein Veblen wrote about in terms of how the relationship between workmanship and salesmanship was often wrongly blurred by treating the cultivation of saleable appearances as a necessary engineering production cost.

Under that rubric, it may be helpful to look at the ways that designers approach their work. Reference to storytelling and narrative are common. It is easy to find assertions that “[t]he story is the primary motivating event that leads to design and innovation.” Or that design is cultural and tells a story about things like place/geography. It is also said that product design can “tap into users’ emotions” by building on a motivating narrative. Indeed, industrial design training courses in “form fundamentals” even emphasize “How Great Storytelling Leads to Great Industrial Design.”

The way that marketing proposals are presented to clients is also informative. It is typical for advertising pitches to include statements about things like “color psychology” to justify choices of colors in terms that are emotive and feelings-based. For instance, “this is yellow as a symbol of kindness, warmth, and empathy.” Whether this is deployed in a way that is scientific or more akin to pseudo-sciences like phrenology or alchemy is worth consideration here. But the fact remains that visual presentations are presented in this manner in real-world scenarios. Whatever criticisms might be made against the bases for these theories, or their use in a given situation, they might well be what a designer of ordinary skill would consider when devising a new industrial design. The crux is the purported link between social meaning and visual appearance that is known or otherwise already available in the art. And reference to marketing, advertising, and branding rather than product design specifically is still fair, because Federal Circuit panels have held—for better or worse—that design patent and trademark standards are analogous and that blurring distinctions between them is harmless. And talk about storytelling and narratives is often framed as simultaneously being about both product design and branding so that users/customers “understand the value of the product and to build a deeper connection with the brand.”

There have been many efforts to analyze social significance of visual representations. A fascinating example is the television documentary mini-series and corresponding book “Ways of Seeing” by John Berger et al. This looked at artworks and assessed, through critical studies, how certain depictions and themes reinforced things like sexism and patriarchy. The analyses presented are open to criticism, particularly in terms of their underlying essentialism (in somewhat the same way patent claim construction rules that seem to simply decree that a given term means one particular thing without explanation). After all, Beethoven’s “Ode to Joy” in his 9th Symphony has been used to represent just about every possible worldview (even fascists used it!), which tends to refute essentialist notions that there is any particular meaning inherent to it. But, still, the “Ways of Seeing” series and book presents a very useful reference (easily accessible to any viewer or reader) that informs how reasonably pertinent problems might be assessed for design patent analogous art. That is, it may be possible to ask what sort of (non-technical/non-functional) social objective is sought to be promoted, and then look at ways that other designers have sought to express those non-visual concepts visually before with the same or different types of articles.

The essentialism of Berger et al.’s approach might be softened or avoided by looking more to something like Pierre Bourdieu’s sociology, which investigates meaning in terms of social fields. Bourdieu’s famous book La Distinction [Distinction: a Social Critique of the Judgement of Taste] is useful in exploring how artistic tastes reflect attempts to draw social distinctions. People’s tastes associate them with one group and distance them from others. To (over)simplify this, taste is less about inherent qualities of artistic works or isolated individual preferences than reflecting social distinctions arising from social factors that have meaning as part of a larger field in which individual instances cluster as nodes. For example, if someone says they “like all types of music except country” they are are probably trying to convey that they are not like the sorts of people who listen to country music. And “disco sucks” epithets were, historically, often effectively dog-whistle homophobic slurs. While Bourdieu’s more formal methods involving surveys will be impractical to routinely apply in patent litigation, a book like David Lee’s Battle of the Five Spot, about why jazz musician Ornette Coleman’s 1959 performances at a New York City club were musicologically significant, shows that the general framework can be applied without extensive surveys.

And this comes up in more seemingly utilitarian contexts as well. A 2021 segment on the long-running British television series Gardeners’ World by Advolly Richmond explored the origins of lawns. These came into being in the later middle ages in Europe on aristocratic estates. They required having many servants to mow them, and technology that made such work feasible. The subsequent expansion of lawns can be seen—though the lens of Thorstein Veblen’s seminal book The Theory of the Leisure Class: An Economic Study of Institutions—as people of lesser means attempting to emulate feudal aristocracy with the aid of improvements to lawn mower technology. That is, lawns were a symbol of aristocratic wealth and privilege and the appearance of a “well kept” lawn evolved into widespread use as a visual symbol meant to convey the owner’s wealth (i.e., ability to hire a servant or available free time to mow him- or herself with a purchased lawnmower device) and/or connection to aristocratic values.

Fads are also relevant here. Take computer presentation slide deck templates. Companies often have these and there are trends/fads that develop such that different templates used by different companies share common features at given times. For instance, one fad was to use blocky sans serif fonts and high-contrast color schemes incorporating bright, vivid colors. Suffice it to say, fads are social determinants that can provide motivations to those devising ornamental designs. And designing slide deck templates is not altogether that different from, say, designing the ornamental appearance of graphical user interfaces and computer-generated icons, which are the subject of design patents. How many companies have explicitly tried to have a minimalist computer search interface that looks “like Google’s”?

What does all this social science framework really tell us about problems faced for those developing industrial designs? Well, if some bit of evidence (more on that later) establishes an intent to modify an existing product design to be more aggressive and powerful looking, then looking to prior art with bigger, thicker, taller, etc. characteristics that create a more aggressive and powerful visual appearance would seem to be analogous in terms of the problem faced, even if pertaining to a different type of article or different field of endeavor.

In a more direct way, there can be situations in which designers reproduce known ornamentation of their own or co-workers. For instance, there might be an explicit intention or goal to “create a sense of continuity and coherence across a brand’s products and services.” Some ornamental feature or general style of ornamentation might simply be copied or ported over to another design project. In the design patent context, this sort of motivation is undoubtedly relevant to questions about the obviousness of re-using and adapting known ornamental aspects of one product to another, even when dealing with different types of products/articles.

The parties in LKQ disputed whether designs solve problems at all. Perhaps another way of looking at that (in a Veblenian way) is to say that most or all designs address the problem of saleability, which is not specific enough to any particular claimed design to be of use for the obviousness analysis. And the word “problem” might imply functional solutions rather than ornamental ones—although dictionaries merely define that word as a question to be considered. But, in this author’s view, the social science guidance discussed above still bears on having a second prong or test for analogous arts for design patents. Perhaps it is simply a matter of renaming the second prong/test, maybe as being about the realization of a type of (visual/social) impression sought rather than the “problem” faced. Here again, we run up against the issue (for another day) of whether ornamental designs are really “inventions” at all.

Evidentiary Considerations

Design patents are scant on text. Their prosecution histories might contain some relevant information about the field of endeavor and/or problem faced, but only on occasion or inferentially (for instance, in terms of what prior art was cited or not cited, or through amendments to the title). And, unique to design patent practice, an unpublished appendix of the original application might contain information relevant to what is analogous art, but not always. Family-related or commonly-assigned or -invented utility patent applications, if they exist, will also be a rich source of information, as they have been for functional vs. ornamental analysis in the past.

In the longer term, design patent applicants might choose to voluntarily insert some sort of problem statement in an application (possibly in the appendix), or the Patent Office might institute a new rule requiring such a statement. While patentees might balk at doing this, it may give the patentee some measure of input or control over the way analogous art analysis proceeds.

Notably, the LKQ decision cites approvingly Airbus S.A.S. v. Firepass Corp., a case that looked at the analogous art “reasonably pertinent” prong/test and said that extrinsic evidence can be considered to link the claimed invention and cited prior art (that fell in a different field of endeavor) by a common technical problem. Airbus relied on KSR to hold that overly strict problem statements cannot be used to limit obviousness to express suggestions to combine references or to otherwise ignore or contradict the background knowledge possessed by a person having ordinary skill in the art. Extrinsic evidence can thus be used to help define the problem faced. And extrinsic evidence will undoubtedly play an even larger role in addressing questions about analogous art status for design patents than with utility patents, particularly when defining the “problem faced” or a similar inquiry.

In litigation, discovery around a designer’s intentions and objectives may be useful. This might convey the problem faced. Advertising by the patentee might also be a fertile source of that kind of information. Do ads highlight a “sleek” look or “curved” lines of the patented product, for instance, like televised car commercials often do? Information about the work experience of a designer named on a design patent might also be relevant to the field of endeavor and scope of “similar” articles.

One difficulty, however, is trying to evaluate any link between a cited prior art design patent or printed publication reference and a common problem faced. If the reference is silent on its face about this, what sort of evidence will either link it to the challenged patented design or differentiate it? A conventional approach is expert testimony. Just in the way copyright litigation can involve expert testimony from musicologists, or the way utility patent litigation involves scientific or engineering expert testimony, there are opportunities to present testimony about links or differences. And, following Airbus, additional extrinsic evidence such as textbooks, printed publications, other patents, etc. might be relevant to link (or differentiate) a given prior art reference. Evidence about fads, trends, or brand/product product line coherence might fall in this category. Another possible approach, less conventional historically, is a survey of ordinary consumers. If we return to the example of making something look more aggressive and powerful, would a significant percentage of ordinary observers use those same words to describe a given prior art reference? Or would a survey somewhat similar to a trademark likelihood of confusion survey also potentially provide relevant evidence? Perhaps such a survey might focus on something other than, or rather more specific than, the overall impression, like aspects of the prior art that are a material part of the overall visual impression to the ordinary observer (and which are shared in common with the claimed design being challenged). Testimony from the designer or author of the cited prior art might be possible, if also potentially subject to attack.

May 2024
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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.

Patents Q&A

What Is Non-Analogous Art?

Under U.S. patent law, a distinction between analogous versus non-analogous art sometimes arises. Understanding when this concept matters, and how to draw a line between these two possibilities may be important. The following article explains what analogous and non-analogous art is, why it matters, and how to determine whether a given piece of prior art is analogous art or not.

I handled a patent application years ago related to fishing lures. The examiner had cited a prior art patent directed to a rocket fuel additive for a rejection in an office action. This fishing lure application was not rocket science, as the saying goes. But could the examiner properly say that a fishing-related invention was obvious because of a prior teaching about rocket fuel additives? The concept of non-analogous art helps to answer that question.

When Non-Analogous Art Status Matters

In order for a prior art reference to be usable to establish obviousness, the reference must be analogous art to the claimed invention. In re Bigio, 381 F.3d 1320, 1325 (Fed. Cir. 2004). Teachings in non-analogous art cannot be relied upon to establish obviousness. However, there is no analogous art requirement for a prior art reference being applied for anticipation. In re Schreiber, 128 F.3d 1473, 1478 (Fed. Cir. 1997).

There are two different ways to establish something is analogous art. Satisfying either one of them is sufficient. Under these tests or prongs, a prior art reference is analogous art to a claimed invention under either of the following circumstances:

  1. the reference is from the same field of endeavor as the claimed invention (even if it addresses a different problem); or
  2. the reference is reasonably pertinent to the problem faced by the inventor (even if it is not in the same field of endeavor as the claimed invention)

In re Clay, 966 F.2d 656, 658-59 (Fed. Cir. 1992).

Although, the evidence and analysis relating to the field of endeavor and reasonably pertinent prongs may overlap. And some prior art might satisfy both tests, even though the requirement is only that it satisfy one of them. However, the analysis for design patents might differ somewhat for the second prong/test.

A Burden To Meet When Disputed

The analogous art requirement is about the factual foundation needed to be able to rely on a given prior art reference for an obviousness argument. See In re GPAC, Inc., 57 F.3d 1573, 1577 (Fed. Cir. 1995); In re ICON Health & Fitness, Inc., 496 F.3d 1374, 1378 (Fed. Cir. 2007). This is not merely about what a given prior art reference literally teaches. It is about whether a person of ordinary skill would have been motivated to look at or otherwise consider a reference at all in relation to the claimed invention at the time of invention (or effective filing date). That makes this a kind of threshold that disallows obviousness arguments premised on obscure, remote, or out-of-context teachings.

This is also an aspect of the well-established notion that an obviousness analysis must not succumb to hindsight bias. Netflix, Inc. v. DivX, LLC, 80 F.4th 1352, 1358-59 (Fed. Cir. 2023). Jorge Luis Borges wrote in “Kafka y sus precursores” [Kafka and His Precursors]” (La Nación, August 15, 1951) that a writer modifies our conception of the past to create precursors. After describing various prior works with elements that resemble Kafka’s later work, he said, “Kafka’s idiosyncracy is present in each of these writings, to a greater or lesser degree, but if Kafka had not written, we would not perceive it; that is to say, it would not exist.” This is not a bad way of thinking about non-analogous art that only appears as a relevant precursor in hindsight. While Borges refers to writers generally, what he really was referring to was Kafka’s new and unique genius rather than ordinary writing that might merely reuse commonplace ideas and styles. This is like talking about inventive genius with patenting.

In the end, establishing that a reference is analogous art is a factual, evidentiary burden that a patent examiner or challenger must satisfy as part of arguing that a claim is unpatentable or invalid as obvious. Although, normally, analogous art status is assumed unless the patentee or applicant asserts that a given reference is non-analogous art. That means this question is not routinely addressed. In practice, it only arises when a patentee or applicant believes that an obviousness argument is improper. So, it is up to the patentee/applicant to raise this issue when applicable. Then the examiner or challenger must be able to show that the reference relied upon is analogous. That involves pointing to evidence that satisfies at least one of the two tests.

Intrinsic evidence, contained in the patent/application and its prosecution history, is generally the best and most significant. It is helpful to look at what is said in the claims, the title, and the background section, for instance, where identifications of technical fields and discussions of problems to be solved are frequently found. Often, this type of evidence alone is sufficient to determine if a reference is analogous or non-analogous art. But extrinsic evidence can also be used. For instance, there might be expert testimony in court about the knowledge and skill of a person of ordinary skill in the art, or reliance on additional patents or publications that indicate the knowledge and skill that prevailed in the art.

The Same Field of Endeavor Test

The field of endeavor test or prong asks whether the art is from the same field of endeavor as the claimed invention, regardless of the problem addressed. Bigio, 381 F.3d at 1325. This test rests on an assessment of the nature of the patent or application and claimed invention in addition to the level of ordinary skill in the art. Bigio, 381 F.3d at 1326.

The field of endeavor is determined by reference to explanations of the invention’s subject matter in the patent or application. This includes the function and structure of the claimed invention, taking into account the complete factual description of all embodiments. So this involves considering similarities and differences in structure and function between the claimed invention and the cited art. The field of endeavor is not limited to the specific point of novelty, the narrowest possible conception of the field, or to a particular focus within a given field. Courts tend to take an expansive view of the relevant field of endeavor. Netflix, 80 F.4th at 1359.

In the Bigio case, it was found that that toothbrush art was analogous to a claimed hair brush invention. In support of that conclusion, the structure and function of the claimed hair brush invention was found to be similar to that of toothbrushes. Both were in the field of hand-held brushes having a handle segment and a bristle substrate segment. Also, it was found that toothbrush prior art could easily be used for brushing hair (e.g., human facial hair) in view of the size of the bristle segment and arrangement of the bristle bundles described in the reference.

Disputes over the proper application of this test are not particularly common, because it is often clear when a reference is or is not from the same field. But when disputes do arise, they tend to center around how broadly or narrowly the relevant field of endeavor should be defined. Patentees and patent applicants will tend to argue for a narrower definition of the field, which tends to exclude more potential prior art. Challengers and examiners may instead argue that the relevant field of endeavor is broad and generic. The correct approach in any particular case is the one best supported by the facts and evidence. In other words, this test requires both accurate identification of and careful review of the relevant facts.

The Reasonably Pertinent Test

The reasonably pertinent test or prong asks whether the reference still is reasonably pertinent to the particular problem with which the inventor is involved, even if the reference is not within the same field of endeavor. Bigio, 381 F.3d at 1325. Sometimes this is discussed in terms of a “purpose” instead of a “problem”, but this means the same thing.

When addressing whether a reference is analogous or non-analogous art to a claimed invention under a reasonable-pertinence theory, the problems to which the claimed invention and reference at issue relate must be identified and compared from the perspective of a person having ordinary skill in the art. The relevant question is whether a person of ordinary skill would reasonably have consulted the reference in solving a relevant problem. Although the dividing line between reasonable pertinence and less-than-reasonable pertinence is context dependent, it ultimately rests on the extent to which the reference and the claimed invention relate to a similar problem or purpose. Donner Tech., LLC v. Pro Stage Gear, LLC, 979 F.3d 1353, 1359-61 (Fed. Cir. 2020).

A reference can be analogous art with respect to a patent even if there are significant differences. Familiar items may have obvious uses beyond their primary purposes. And, for instance, a person of ordinary skill might reasonably consult a reference even if she would not understand every last detail of it, so long as she would understand the portions relevant to solving her problem well enough to glean useful information. Yet the pertinence of the reference as a source of solution to the inventor’s problem must be recognizable with the foresight of a person of ordinary skill, not with the hindsight of the inventor’s successful achievement. Sci. Plastic Prods., Inc. v. Biotage AB, 766 F.3d 1355, 1359 (Fed. Cir. 2014).

Also, the articulation of the purpose of or problem to be solved by the patent cannot be so intertwined with the field of endeavor as to effectively exclude consideration of any references outside that field. The second prong cannot be collapsed into the first. It must remain a distinctly additional way of establishing analogousness. Donner, 979 F.3d at 1360. And, further, the so-called teaching, suggestion, or motivation (TSM) test for obviousness was overturned by the Supreme Court in KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007). That means overly strict problem statements cannot be used to limit obviousness to express suggestions to combine references or to otherwise ignore or contradict the background knowledge possessed by a person having ordinary skill in the art. Airbus SAS v. Firepass Corp., 941 F.3d 1374, 1383-84 (Fed. Cir. 2019).

The Airbus case involved a patent that claimed “A system for providing breathable fire-preventive and fire suppressive atmosphere in enclosed human-occupied spaces” and addressed the problem of fire prevention and fire suppression. The cited reference that the patentee alleged was non-analogous was a prior patent by the same inventor that disclosed equipment for providing hypoxic air in an enclosed area for the purposes of athletic training or therapy. Four additional prior art references (that is, other extrinsic evidence beyond the cited reference alleged to be non-analogous) established that use of normbaric hypoxic atmospheres in enclosed environments was well-known in the art of fire prevention and suppression at the time of the invention. The court found that an ordinarily skilled artisan seeking to address the problem identified by the patent in question would reasonably have consulted the cited reference relating to enclosed hypoxic environments because it was reasonably pertinent to a similar problem, even though it was from a different field of endeavor. The court therefor overturned a prior decision refusing to consider the extrinsic evidence about knowledge that was available in the art, which linked the challenged claim and the cited prior art reference by a common technical problem.

In re Klein, 647 F.3d 1343, 1350-51 (Fed. Cir. 2011), involved a claimed invention addressing the problem of “making a nectar feeder with a movable divider to prepare different ratios of sugar and water for different animals.” The purpose of a first group of references was separating solid objects. But none of them showed a partitioned container adapted to receive water or contain it long enough to be able to prepare different ratios in the different compartments. A second group of references was directed to containers that facilitate mixing two separated fluids together. But the second group did not show a movable divider or the ability to prepare different ratios. The court ruled that an inventor considering the relevant problem would not have been motivated to consider any of the cited references. Accordingly, they were non-analogous and did not qualify as prior art for purposes of obviousness. Rejections of the claims were reversed.

There tend to be more disputes over application of the reasonably pertinent prong than the field of endeavor prong. But just as with the other prong, patentees and applicants are incentivized to define the relevant problem narrowly. Examiners and challengers may define the problem more broadly and generically. Reasonable pertinence rests on what is best supported by the relevant facts. For example, a statement of the relevant problem that is inconsistent with the discussion in a patent or application, viewed as a whole, is likely incorrect—whether broader or narrower than they way the disclosed invention was described. And extrinsic evidence from other patents, expert testimony, etc. can be used to establish pertinence. So even if a given patent is very short and says relatively little about problems faced in the art, other evidence might inform that inquiry.


The analogous versus non-analogous art question establishes whether or not a given reference qualifies as prior art for purposes of obviousness. But it is not applicable to use of the same reference for an anticipation/novelty analysis. This factual question is rarely explicitly discussed in practice and usually it is assumed that any cited art is analogous. That is partly because courts have generally taken an expansive view of what qualifies as analogous. But, at the end of the day, whether a reference is analogous or not is just one facet of the fact-intensive obviousness analysis. An obviousness position requires solid evidence and a good, logical argument. Reliance on non-analogous art is simply a type of bad argument resting on deficient evidence.

In my example of a fishing lure invention and a rocket fuel additive reference, the examiner eventually did acknowledge that his cited reference could not be relied upon for an obviousness rejection. It was bad optics. The argument that “this is not rocket science” when dealing with the patentability of a fishing lure invention was clearly a winning one (and a fun one to be able to make!). In particular, rocket science and fishing lure design and manufacturing were different fields of endeavor. And prior art about fuel additives designed to influence combustion properties had no bearing on the purposes of the fishing lure invention, which was intended to provide certain weighting characteristics during use without causing environmental pollution. So this was a stark illustration of non-analogous art.

Sometimes looking to disparate fields and combining teachings that were, individually, already known can be the product of true invention. Of course, on the other hand, sometimes an alleged invention is obvious and unpatentable. Simply because an applicant or patentee finds a cited reference to be inconvenient does not make it non-analogous art. The non-anlogous arts tests are occasionally useful as a way to draw the line between patentable and unpatentable ideas.

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.

Patents Q&A

What Is a Negative Limitation?

Patents and patent applications have claims that define an invention. Those claims can have various elements or limitations to recite aspects of the invention. But what is a negative limitation? This article explains what they are and some considerations about whether and when they are permitted.

Basic Definition

In the simplest terms, a negative limitation in a patent claim defines an invention in terms of what it is not, rather than what it is. Any limitation in a patent claim that does this can be considered a negative limitation. Although, there are many different ways negative limitations can arise or be worded. There is no standard format for a negative limitation. Indeed, whether or not something constitutes a negative limitation might even be disputed.

When design patent claims include negative limitations is an interesting question that courts have not definitively resolved. The discussion that follows focuses mostly on utility or invention patents.

Example Negative Limitations

The following are some examples of patent claims with negative limitations.

“1. An apparatus comprising: a first panel; and a second panel, wherein the second panel is arranged parallel to and in direct contact with the first panel, wherein the first panel is perforated, and wherein the second panel is a continuous sheet of material without perforations.”

In this example claim 1 above, the limitation that the second sheet is “without perforations” is a negative limitation. It states what is not present (perforations). The negative limitation further defines what the limitation “a continuous sheet of material” means. It also emphasizes a difference from the first panel, which is perforated.

“2. A system comprising a printed circuit board having a first electrical conductor, wherein the first electrical conductor does not have a sinusoidal shape.”

Example claim 2 above includes the negative limitation “wherein the first electrical conductor does not have a sinusoidal shape.” This limitation does not specify the shape of the first electrical conductor. Instead, it specifies the shape that it does not have. That is, this limitation excludes one possible type of shape.

“3. An apparatus comprising: a platform; and one and only one pillar connected to the platform.”

In example claim 3 above, the recitation of “one and only one pillar” includes a negative limitation. It is actually both a positive recitation of a pillar and a negative limitation excluding the presence of more than one pillar. Recitation of a “single” element—as in “a single pillar connected to the platform”—is a similar type of negative limitation.

Different But Related Concepts

There are some other concepts in patent law that have similarities to negative limitations but are distinguishable in some way.

Closed and Partially Closed Transitional Phrases

Transitional phrases in patent claims can be closed or partially closed. The closed transitional phrase “consisting of” excludes the possibility of other elements being present. For instance, in a chemical compound this closed transitional phrase can be used to exclude the presence of additional substances. The partially closed transitional phrase “consisting essentially of” is limited to the explicitly recited elements and those that do not materially affect the basic and novel characteristic(s) of the claimed invention.

Closed and partially closed transitional phrases are not negative limitations in the strict sense. That is because they are transitional phrases and not substantive claim limitations or elements. However, they may have a rather similar effect as exclusionary negative limitations.

Reciting Holes, Voids, Etc.

A limitation directed to “a hole,” “a gap,” etc. is not strictly a negative limitation. But it also can partly resemble one. It is generally preferable to claim surrounding structures that define a hole, aperture, passageway, void, empty space, or the like. This avoids the awkwardness of trying positively claim nothing or the absence of something.

Are Negative Limitations Permitted?

In the U.S., negative claim limitations are not categorically prohibited. But that does not mean they are necessarily proper. Whether they are permitted depends on the context, including the scope of the limitation, support (or lack thereof) in the original disclosure, and the timing of introduction of the negative limitation.

A negative limitation that seeks to exclude the prior art and claim everything else is often problematic. Such claims tend to be based on the desired scope of a patent monopoly rather than pointing out the subject matter regarded as the invention. In other words, this kind of claim tries to carve out and exclude the prior art while preempting everything else. That might mean reciting a given result (perhaps using functional language) while excluding unpatentable prior art solutions. Courts have long disfavored this kind of approach and tend invalidate such claims one way or another. For instance, such a claim may be indefinite. This makes sense because peripheral claiming rather than central claiming is used in the United States.

Attempts to add a negative limitation by way of a later amendment can raise additional issues about support. For instance, if the original disclosure explicitly listed multiple alternatives, that is generally sufficient to later introduce a limitation to exclude one or more of them. However, silence will not generally suffice to support a negative claim limitation. So the ability to later add one by amendment in response to a rejection may depend on the sufficiency of the original disclosure. Claims present at initial filing (including in a preliminary amendment) are considered part of the original disclosure and may support themselves.

Best Practices: Is a Negative Limitation a Good Idea?

Negative claim limitations are generally disfavored. Patent attorneys usually try to avoid using them. As already discussed, they can sometimes raise issues about validity. Negative limitations that make up the entire recitation of the point of novelty, without more, have a greater chance of raising those kinds of problems than ones that merely clarify or elaborate on positively-recited elements. Claims with negative limitations also are sometimes easier to avoid when designing around a patent. This may impact how valuable or desirable it is to have them.

Yet, there are times when negative limitations fairly and helpfully delineate an invention. They are permitted in many instances and may be useful in the right context.

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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.

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.


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.

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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.

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.


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.


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.


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.

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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.

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.


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.


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.

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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.

Patents Q&A

How Do AFCP 2.0 Requests Work?

The U.S. Patent & Trademark Office (USPTO) has a patent-related pilot program called the After Final Consideration Pilot 2.0 or “AFCP 2.0”. How does this AFCP program work, and how can these requests be made? This article addresses those basic questions.

Basic Contours of the Pilot Program

AFCP 2.0 is meant to foster compact prosecution. It aims to reduce the number of requests for continued examination (RCEs) and to foster examiner-applicant collaboration. To do that, the program authorizes additional time for examiners to search and/or consider qualifying responses after a final rejection. The program also involves an examiner-initiated interview if the response does not result in allowance. Some information about the program is available from the USPTO online, including some limited answers to frequently asked questions (FAQs).

The crux of the AFCP 2.0 program is that it expands the amount of time examiners have to act on a given after-final amendment to a pending patent application. Understanding how time constraints work during examination and how AFCP alters them is therefore important in order to grasp how the program may or may not benefit an applicant. However, the USPTO does not widely publicize how much time examiners have to begin with to consider an after-final response, or how much additional time is provided. These time constraint matters are taken up below.

Currently, participation in the program is free, but the USPTO has proposed an official fee requirement intended to go into effect in 2025.

As a pilot program, AFCP is implemented yearly. But it has been renewed every year since its inception.

Examination Time Constraints

The first point to understand is the “count” system that governs USPTO examiners’ work. Essentially, it is tied to a collective bargaining agreement with the unionized examination corps. This count system is complex. But the most important feature is that it basically allocates a fixed amount of time for examiners to spend on a patent application, based upon pre-determined levels of technological complexity and the particular assigned examiner’s seniority status. This averages only about nineteen or twenty hours per application, but can be much less or much more than that for a given application. For instance, some examples of these time variations by technology area are given here and here. And an explanation of examiner seniority-based variations is found here.

Under normal circumstances (not under the AFCP program), an examiner may spend only about 30 minutes considering an after-final response.

The USPTO’s Federal Register notice and web page about AFCP mentions only “a set amount of time”, without specifying the length of additional time allocated. But relevant information is available elsewhere. In actuality, the additional examination time allocated for each granted AFCP 2.0 request is 2-3 hours. For utility and plant applications, there is an additional two hours of substantive search/consideration time plus one extra hour of time for an interview (which can be reallocated for substantive examination potentially, in the absence of an interview). For design applications, there is only one additional hour of substantive examination time, plus the same one hour of additional interview time (which can also be reallocated in the absence of an interview).

Eligibility Requirements

There are a number of requirements to for an after-final amendment to qualify for this pilot program. The most important ones are:

  • There is an outstanding final rejection of at least one claim
  • An amendment is made to at least one independent claim that does not broaden the scope of that independent claim in any aspect
  • A certification and request (on USPTO form PTO/SB/434) is filed with the responsive amendment

The complete requirements can be found on the USPTO’s AFCP request form or via the USPTO’s program explanation web page.

Importantly, the required amendment to an independent claim does not have to be a narrowing amendment. It could merely be a clarification or correction of an error. Also, the program does not preclude a broadening amendment to another claim.

How to Make an AFCP Request

The key to making an AFCP request is to submit the required USPTO form along with an after-final amendment that meets the eligibility requirements discussed above. These requests must be filed electronically and not in hard copy by mail. The request form looks like this:

Image of main page of the USPTO's "Certification and Request for Consideration Under the After Final Consideration Pilot Program 2.0", form PTO/SB/434 (version 3-22)
USPTO AFCP 2.0 Certification and Request form PTO/SB/434 (version 3-22 shown)

Currently, there is no fee for this request. However, the USPTO has proposed an official fee requirement intended to go into effect in 2025.

The certification on the form indicates that the applicant is willing and able to conduct an interview. Nonetheless, substantive program materials contemplate that an applicant might later be unavailable or refuse an interview—contrary to what is stated at the end of section 8 of the USPTO’s certification and request form.

Is an AFCP Request Worthwhile?

Is it worthwhile, or a good idea, to make an AFCP request? Every case is different and there is no one correct approach. From an applicant’s perspective, an AFCP request is relatively easy to file. And the time needed for an interview may be short and not by itself a deterrent to making a request. So an AFCP request is often worth making if an independent claim is being amended. Whether it is desirable to amend a claim merely to qualify for AFCP 2.0 is another question entirely, and not something automatically recommended as a general matter (but possibly worthwhile in some circumstances).

This program tends to be most effective with relatively straightforward amendments. Or with amendments resulting from an examiner interview. Amendments implementing something essentially already suggested by the prosecution history tend to get a lot of benefit from it.

But the additional time allocated by an AFCP 2.0 request is not that large. That is particularly true if significant searching and consideration by the examiner is necessitated by a given response. Substantial, complex, or extensive amendments and/or arguments often require more examiner time to evaluate. These might not be resolved through the program. Applicants cannot expect miracles. All this is to say that after-final practice runs up against the count system and the time examiners are willing and able to allot to handling applicant responses. AFCP 2.0 may give examiners a little more time, but whether that additional time is enough time will vary widely on a case-by-case basis.

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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.

Patents Q&A

What Is the Deadline to File a Continuing Patent Application?

A continuing patent application such as a divisional, continuation, or continuation-in-part (CIP) is possible in the USA. But what is the deadline to file one of these applications?

What Is a Continuing Patent Application?

A continuing patent application is one that claims priority to (or the domestic benefit of) a prior U.S. patent application or PCT international application that designated the USA. (See 35 U.S.C. §§ 120 and 121 and 37 C.F.R. § 1.53(b)). That means these are follow-on patent applications. They always relate back to one or more prior “parent” application(s). These can also be referred to as “child” applications in a patent “family”.

In other countries, the terminology for continuing applications may differ. For instance, many countries permit only subsequent “divisional” applications, and do not have different names for different types of continuing applications.

Deadline to file a Divisional, Continuation, or CIP Patent Application

Section 120 of the U.S. patent laws establishes that a continuing application (including divisionals, continuations, and CIPs) must be filed “before the patenting or abandonment of or termination of proceedings” of a parent application. In addition, USPTO regulations under 37 CFR § 1.78(d) state that a continuing application can be filed while the parent application is “copending”.

The Federal Circuit has ruled that so-called “same-day” continuing application filings are permitted, meaning a continuing application can be filed on the same day that a parent application issues as a patent. This confirmed longstanding U.S. Patent & Trademark Office (USPTO) practice, despite the statutory language literally saying “before” rather than “copending” or referring to the same day of patenting. Currently, this means that continuing applications can be filed up to and including the date that a parent application issues as a granted patent.

Another important aspect of the USPTO’s “copending” requirement is that the parent case cannot be abandoned. If the parent case will not issue, but an office action or the like is outstanding, then it is necessary to file the continuing application either (a) during the shortened statutory response period in the parent case or (b) after the shortened statutory period but before the maximum six-month statutory period along with the payment of monthly extension of time fees in the parent application. In other words, extension of time fees may be required in the parent case in order for the continuing application to be considered “copending”. This is referenced obliquely in MPEP § 710.02(e) and more clearly in old USPTO notices.

For continuing applications related to a prior PCT international application, such as a PCT “bypass” application in the U.S., the USPTO’s “copending” requirement means that the continuing application must be filed by the national phase entry deadline. In the U.S. this is 30 months from the earliest priority date.

The deadlines for continuing applications in other jurisdictions (often referred to only as divisionals) varies considerably. Deadlines for divisional or other continuing applications in foreign patent offices may arise much sooner than the deadlines under U.S. patent law and practice. For instance, Brazil requires divisional filing before a final office action or allowance is issued, which is a date that cannot be precisely determined in advance.

Best Practices

It is a best practice to file any continuing application as early as possible, and in the USA no later than with the payment of the issue fee or by the shortened statutory period deadline for a response in the parent case. While it may be possible to file a continuing application after such a date, problems and additional fees could arise.

For example, the Federal Circuit decision allowing continuing application filings on the same day as issuance of the parent is contrary to the literal language of the status, and might be overturned someday. There may also be filing system outages, illnesses or other complications that make a last-minute same-day filing difficult as a practical matter.

Also, the USPTO’s switch to “eGrant” electronic-only patents means that the delay between issue fee payment and subsequent issuance will become shorter than when hard copies were printed and mailed in the past. Indeed, on this point the USPTO has formally commented that reducing patent pendency is required by statute, while giving applicants time to file continuing applications is not, so “[a]pplicants should file their continuing applications as early as possible, preferably prior to payment of the issue fee to avoid any loss of rights.”

If an office action is outstanding in a parent case that will be abandoned, filing continuing applications early also avoids the need to pay an extension of time fee in the parent. The need to pay that extension of time fee in the parent might also be easily overlooked and missed, jeopardizing any resultant patent.

Also, delayed continuing application filings can implicate other considerations such as double patenting (and terminal disclaimers), prosecution laches, and the prior art status of a publication of a parent application (particularly for CIP applications).

Lastly, delays in filing a continuing application may also delay examination and erode the available term for any resultant utility or plant patent issuing from a continuing application. (However, this point is not a concern for design patents, which have a fixed term from issuance).

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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.

Patents Q&A

What Is a Published Patent Application?

People unfamiliar with patents and patent law are often confused about published patent applications. This article provides a brief overview of what a published patent application is and, importantly, how it differs from a granted patent.

Contents of a Published Application

Pre-grant publication means that patent applications that have not yet been fully examined are published while still pending. This gives the general public a view of the contents of the pending application. And even if no patent is ever granted, the contents of the published application are normally still made public (with some exceptions). Published patent applications can be relied upon as prior art against later applications. In the USA, only non-provisional utility and plant patent applications are subject to pre-grant publication. Pre-grant publication normally occurs after eighteen months have elapsed from the earliest priority date.

A published patent application—or patent application publication—will take a form determined the relevant jurisdiction. In the USA, for example, each application is specially formatted for pre-grant publication in a two-column format using paragraph numbers. This means the appearance of the published application will differ from what the applicant(s) originally filed.

Excerpt of the front page of United States Patent Application Publication Number US 2023/0000001 A1 to Weinan Wu for an "Assembled Garden Tool"
Example excerpt from front page of U.S. patent application publication no. 2023/0000001
Excerpt of the first page of text of US 2023/0000001 A1 for an "Assembled Garden Tool" showing two-column format with paragraph numbers
Example excerpt from first page of text of U.S. patent application publication no. 2023/0000001

The published application might also include amendments, such as amendments to the claims or drawings. In some uncommon instances, amendments might be published that are later disallowed and omitted from a subsequent granted patent. But amendments submitted too late for inclusion might not be included with the publication. And appendices included in patent applications are generally not published. The USPTO can refuse to publish certain information prohibited by law or that is offensive or disparaging. Additionally, as a consequence of official preparations and formatting efforts for publication, there can sometimes be discrepancies and printing errors, in which the published version unintentionally differs from the applicant’s original application.

In some other jurisdictions, such a PCT application publications, published applications merely take copies of the application as filed by the applicant and add a cover sheet. In other words, the application is not reformatted and reflects what the applicant submitted.

Publication Numbers

Each patent application publication is assigned an official publication number. In the USA, and with PCT matters, the publication number differs from the application serial number assigned upon filing by the relevant patent office. Although in some jurisdictions the publication number may be the same or nearly the same as an application serial number.

The anatomy of a publication number in the USA is shown as follows:

graphic labeling the country code, pub. year, unique number and kind code for the publication number of U.S. patent application publication no. US 2023/0000001 A1
Anatomy of a U.S. patent application publication number

There is a four-digit year followed by a slash followed by a seven-digit number unique to each published application, and the concluded with a kind code. The unique-seven digit numbers are sequentially assigned to each newly published application. The kind code indicates the type of publication, with “A” generally indicating a published application and “B” generally indicating a granted patent. A two-letter country-code prefix to patent publication numbers can also be present, or appended, to indicate the jurisdiction of the patent publication.

Be aware that some patent searching databases use confusing variations on official patent publication numbers and kind codes. For instance, the Espacenet portal from the European patent Office (EPO) truncates U.S. published application numbers and shortens the unique seven-digit number to a six-digit number (but dropping a leading zero). Also, some databases will retroactively apply an “A” kind code to old granted U.S. patents, from before the USPTO began printing kind codes on patents or making pre-grant publications at all.

Each jurisdiction has a slightly different format for publication numbers. For instance, PCT publication numbers have a “WO” country-code prefix and use a six-digit unique identification number.

Example publication number for PCT international publication number WO 2023/000001 A1, published in German
Example publication number for PCT international publication number WO 2023/000001 A1

Publication Makes File Wrapper Available Too

Before publication, the substantive contents of pending patent applications are kept confidential by the U.S. Patent & Trademark Office (USPTO). But upon publication, which normally happens after eighteen months from the earliest priority date, the file wrapper of a published patent application is also made public by the USPTO. This allows the public to monitor the status and ongoing prosecution history of the corresponding application. While the “published application” is a discrete, stand-alone document, its publication also makes other information publicly available too. But, strictly speaking, a published application refers only to the stand-alone published version of the application and not to other materials in a file wrapper made available to the public through other channels.

Differences From a Granted Patent

A published patent application is much different from a granted patent (also called an issued patent). This is often misunderstood. Although the differences between published applications and granted patents are very significant.

In all but a few countries, patent applications must undergo a substantive pre-grant examination that establishes patentability before a patent is granted. A pre-grant patent publication merely indicates that the applicant(s) are seeking—or previously sought—a patent. But there are no enforceable patent rights unless and until a patent is granted. The existence of a published application for an application that is still pending simply means that a patent might be granted. Plus, the scope of the claims in any later-granted patent may differ from those in the published application. By way of analogy, just because someone files a lawsuit does not mean that he or she will win the case or that all the allegations are all true.

A common mistake is to refer to a published patent application as a patent. But they are not patents! It is reasonable to call them patent documents, or patent-related documents. But a published application is not directly enforceable by itself. Only a granted patent can be enforced. This is the most important distinction. A published patent application does not present immediate and direct infringement risks like a granted patent. Although the technical teachings and disclosures in a published patent application may still be prior art against later patent application claims. Yet a published application and a later related patent are often merely cumulative, meaning (apart from different publication dates) they are redundant in terms of their substantive teachings.

Another potentially confusing aspect of published patent applications is that you cannot understand the current status of the underlying patent application from the published patent application alone. A given published application may have matured into a granted patent since publication, or might have been abandoned (and/or another related “child” application might have been filed too). It is necessary to look up the current status in official records, such as though the USPTO’s Patent Center portal. Most paywalled, proprietary patent searching databases provide at least some status information, and a few (but definitely not all) free, open-access patent searching databases provide some status information. But finding and interpreting current status information is not always straightforward.

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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.

Patents Q&A

When Are Patent Applications Published?

Most patent applications are normally published while still pending and prior to the grant/issuance of a patent. Such publication allows the public to see the contents of the application and expands the publication of technical information to include applications that do not turn into granted patents. But when does this pre-grant publication normally occur? And are there any exceptions or variations in the normal publication schedule? This article addresses issues around when patent applications are published occur prior to grant.

When Publication Normally Occurs

In the USA, any new utility or plant patent application is normally published after eighteen (18) months have elapsed from the earliest filing date. The 18-month publication period is based on the earliest effective filing date or priority date. So if there was a prior provisional or foreign priority application, or the application is a continuing application, the 18-month timeline runs from the earliest priority or “parent” application’s filing date rather than the filing date of the current application. Publication normally occurs as soon as possible after the 18-month deadline arrives. In practice, there may be administrative delays in publication. As a result, it might not always happen at exactly eighteen months.

However, U.S. design patent applications and provisional patent applications are never published before grant (35 U.S.C. § 122(b)(2)(A)). Also, reissue patent applications are not published because they always relate to a prior patent that was already granted and therefore already publicly available.

PCT international patent applications are also published after eighteen months (PCT Art. 21). Most other jurisdictions publish patent applications after eighteen months too. Sometimes this public availability in other countries is referred to as providing “laid open” patent applications.

Exceptions to the Normal Publication Schedule

There are some exceptions to the default 18-month pre-grant publication of utility and plant patent applications.

Sometimes pre-grant publication is delayed or does not occur at all. In the USA, applicants can expressly request non-publication, which is only possible if no foreign patent protection is sought. If a non-publication request is filed, the patent and related file wrapper contents only become accessible when a patent is granted, if at all. There can also be secrecy orders that delay publication (and grant of a patent) when the application’s subject matter implicates national security interests. And applications that are no longer pending at eighteen months are not published. That situation arises if a patent is granted in less than eighteen months or if an applicant files a timely express abandonment request.

It is also worth noting that pre-grant publication only began in the U.S. starting with applications filed on or after November 29, 2000. So pre-grant publications simply did not exist in the USA prior to that time frame. Although pre-grant publications have existed in many other countries for a much longer time.

Occasionally pre-grant publications will occur earlier than the usual 18-month schedule. For instance, applicants in the U.S. can expressly request early publication and/or republication, although such requests are rare.

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.