Obviousness in Patent Law

What is Obviousness?

One of the central concepts in patent law is "obviousness". An invention must be non-obvious in order to merit patent protection. The core of determining whether an invention is obvious is whether the claimed invention would have been obvious to a person of ordinary skill in the art based on publicly available information at the time the invention was submitted in a patent application. Non-obviousness is not the only patentability requirement, and it interplays with other patentability criteria, including the patent eligible subject matter, novelty, and utility requirements. This article explains obviousness under 35 U.S.C. § 103, and examines key concepts such as skill in the art, prior art references, and court decisions that shape the meaning and application of obviousness under US patent law.

Understanding Patent Obviousness

Obviousness is a legal standard used to assess whether a claimed invention is sufficiently inventive or merely an obvious extension of existing knowledge. An invention is obvious if someone of ordinary skill in the art would have found it obvious to conceive of the claimed subject matter (i.e., all the claimed elements of the invention) based on one more prior art references as of the effective filing date of the patent application. An claimed invention can be rendered obvious by a single reference or a combination of prior art references that are related to the claimed invention. There are several rationales as to why a person of ordinary skill in the art would find that the invention would have been obvious. A proper application of one of these rationales must be articulated by the patent office in order to support the legal conclusion of obviousness: a "prima facie case of obviousness". Several of these rationales are discussed below.

Ordinary Skill in the Art

The concept of "ordinary skill in the art" is crucial in obviousness determinations. It refers to the level of expertise possessed by a hypothetical person working in the relevant field at the time of the invention. A "person of ordinary skill in the art" ("POSITA") is a hypothetical person who possesses the average knowledge and expertise typical of professionals in the relevant technical field at the time of the invention. As an example, in the case of automotive engine technologies, a technician trained with respect to automobile engine function, parts, assembly, and repair may be a POSITA.

This standard is used in patent law to assess not only obviousness, but also other patentability criteria. One of ordinary skill in the art is presumed to be aware of all relevant prior art and capable of understanding and applying it in a routine manner or with ordinary skill. However, if extensive experimentation or inventive skill would be required, the invention is not obvious. The characteristics of this hypothetical individual, the POSITA, help determine whether a claimed invention would have been obvious or non-obvious in light of existing knowledge and technologies. This "person of ordinary skill" serves as a benchmark for assessing the obviousness of a claimed invention.

Prior Art and Its Role

Prior art encompasses all existing knowledge and technologies relevant to the claimed invention at the time the patent application is filed. Prior art references include patents, published articles, existing products, and any other public information. These references are critical in establishing whether a claimed invention is obvious.

Prior Art References and Their Relevance

A prior art reference must disclose information relevant to the claimed invention in order to form a basis for an obviousness rejection. For example, a prior art reference may teach a method or device similar to the claimed invention, suggesting that the invention would have been obvious. Additionally, a prior art reference must be analogous art—meaning that it is from the same field of endeavor or it is reasonably pertinent to the intended purpose of the invention. Only prior art that falls within this category may be prior to the obviousness inquiry.

As an example, if the claimed invention is a handheld blow dryer designed for drying hair, featuring a compact design, incorporating a fan, heating elements, and an adjustable airflow mechanism to allow users to control the temperature and intensity of the airflow. Although an industrial paint-drying system and the blow dryer share similar components, such as a fan and heating elements, the prior art reference may be non-analogous because it operates in a completely different field of endeavor. The industrial paint-drying system is designed for large-scale automotive applications, involving high-powered equipment to dry paint on car bodies in a manufacturing setting. In contrast, a blow dryer is designed for personal grooming, with specific considerations for safety, portability, and ease of use in a domestic environment. The functions, purposes, and operating environments of these two systems are substantially different. Thus, it is not likely that a person of ordinary skill in the art of designing handheld blow dryers would look to the field of industrial paint-drying systems for solutions. The industrial paint-drying system would be considered non-analogous art.

Examples of Obvious Subject Matter

Example 1: Adjustable Standing Desk with Built-in Monitor Mount

Let's assume that someone develops a "new apparatus" in the form of a height-adjustable standing desk that includes a built-in monitor mount. The desk allows users to customize their workstation setup for ergonomic comfort.

Why It Is Obvious?

This invention, while novel in its specific combination of features, is deemed obvious because the prior art includes both height-adjustable desks and monitor mounts as separate components, and a monitor mount is a known prior art device routinely combined with desks. The concept of combining these elements to create a more ergonomic and customizable workspace would have been evident to a person of ordinary skill in the art. An obviousness analysis would find that motivation to improve workplace ergonomics and efficiency would naturally lead to the integration of these known elements, making the invention an expected development rather than a patentable innovation.

Example 2: Cell Phone case with Built-in Charging Coil

The invention is a protective smartphone case that includes an integrated wireless charging coil. The case connects to the smartphone’s charging port via a small, flexible connector. When the phone is placed on a wireless charging pad, the coil in the case receives power and transfers it to the smartphone, allowing the device to charge without needing to remove the case.

Why It Is Obvious?

While this technology may be novel, the prior art teaches wireless charging technology as many smartphones and accessories already operate with wireless charging. Integrating a wireless charging coil into a case is a straightforward application of this prior art invention, requiring no significant innovation. Additionally, there is a clear trend in accessory development toward multifunctional products, particularly cases that offer added features such as extra battery packs or kickstands. Incorporating wireless charging into a protective case aligns with this trend and would be obvious to one of ordinary skill in the art.

Legal Framework and Court Decisions

The legal framework governing patent obviousness is shaped by various court decisions, particularly those from the Federal Circuit and the Supreme Court. These decisions provide guidance on how to apply the obviousness standard in different contexts.

The America Invents Act (AIA) and the KSR Standard

The America Invents Act (AIA) came into effect on March 16, 2013, shifting the U.S. patent system from a first-to-invent to a first-inventor-to-file system, impacting the time focus for determining obviousness. Under the AIA, the obviousness inquiry now considers the state of the art "before the effective filing date of the claimed invention" rather than "at the time the invention was made." This shift means that references in the KSR International Co. v. Teleflex Inc. decision to "at the time of invention" should be interpreted to align with the AIA’s new focus. The interpretation of what a "prior art reference taught" must now be assessed in light of this new timeframe.

The Graham Factors and Their Continued Importance After KSR

The Supreme Court decision in KSR v. Teleflex Inc. reaffirmed the approach established in Graham v. John Deere Co., which involves determining:

1. The scope and content of the prior art,
2. The differences between the prior art and the claims,
3. The level of ordinary skill in the art, and
4. Objective evidence of nonobviousness (secondary considerations).

These "Graham factors" remain central to obviousness inquiries. The past court decisions discussed in KSR, including Graham, provided an outline for making a case that a claimed invention is prima facie obvious in view of the prior art. The obviousness inquiry is still grounded in the objective inquiries of non-obviousness set forth in Graham, and related cases, such as United States v. Adams, Anderson’s-Black Rock, Inc. v. Pavement Salvage Co., Sakraida v. AG Pro, Inc., and In re Kahn.

Flexibility in the KSR Approach to Obviousness

The KSR decision introduced a flexible approach to obviousness, particularly regarding how to understand what a prior art reference taught and the reasoning to modify or combine prior art elements. The Supreme Court asserted that persons of ordinary skill in the art possess ordinary creativity and common sense, which should be considered when evaluating whether a second prior art reference could be combined with the first. This flexibility extends to assessing whether the combination of these prior art inventions would have been obvious. Previously, the question of whether it would be obvious to combine the teachings of multiple prior art references was answered by whether there was a teaching, suggestion, or motivation provided within the four corners of the prior art reference documents. The Supreme Court decided that this approach was too restrictive. The KSR decision expanded the basis for finding obvious modifications or combinations of prior art can be found from any existing motivation in the prior art (e.g., an existing problem known to one of ordinary skill in the art, but not discussed in the prior art references). Subsequent Federal Circuit cases fleshed out the application of the KSR decision, e.g., considering not only the explicit teachings of the prior art but also the reasonable inferences a POSITA might draw. See, e.g., Randall Mfg. v. Rea, 733 F.3d 1355 (Fed. Cir. 2013) and Zup, LLC v. Nash Mfg., 896 F.3d 1365 (Fed. Cir. 2018) demonstrate the importance of

Prima Facie Case of Obviousness - The Need for Articulated Reasoning and Evidentiary Support

While KSR allows for flexibility, it does not eliminate the need for articulated reasoning and evidentiary support in making a prima facie case of obviousness. The Federal Circuit has repeatedly emphasized that any assertion that a claim is prima facie obvious must be supported by a clear and reasoned explanation, grounded in facts provided in the prior art relied on by the challenger. Cases like Mintz v. Dietz & Watson 679 F.3d 1372 (Fed. Cir. 2012) and Arendi S.A.R.L. v. Apple Inc. 832 F.3d 1355 (Fed. Cir. 2016) highlight that merely citing common sense, without a detailed analysis of how the prior art taught the claimed elements, is insufficient. For example, citing multiple patents for disclosure of various elements of the invention without clear articulation as to why the elements would be combined is insufficient.

Consideration of All Relevant Evidence

In determining whether an invention is obvious, all relevant evidence, including secondary considerations (objective indicia of non-obviousness), must be weighed. Ignoring such evidence can lead to an incorrect outcome. This includes considering what each prior art reference taught, how a POSITA would combine prior art elements, and whether the combined prior art inventions render the claim obvious. Office personnel must reweigh all evidence throughout the examination process to establish a thorough and well-supported obviousness determination.

Application of Reasoning to Facts

The obviousness inquiry is a legal determination based on underlying facts. There must be factual findings regarding what the prior art taught and whether combining prior art elements would have been obvious to a POSITA. After making these findings, they must apply reasoning consistent with Graham and KSR to determine if the patent claims are obvious in view of the cited prior art. The decision-maker must clearly articulate how these facts lead to the conclusion of obviousness. It is critical to provide a reasoned explanation that connects the prior art reference teachings to the legal conclusion of obviousness.

In summary, KSR has reinforced a flexible but rigorous approach to determining obviousness, emphasizing the need to articulate how prior art references taught the claimed device or method and whether it would have been obvious to combine references, all while considering relevant evidence and providing clear reasoning in support of the determination.

Assessing Obviousness: The Established Bases for a Prima Facie Case

The doctrine of obviousness in patent law can be applied through various bases for rejecting a claim as obvious. These bases are drawn from established case law and are reflected in several key areas:

Combining Familiar Elements Using Known Techniques to Achieved Predictable Results: A claimed invention is likely to be considered obvious under 35 U.S.C. § 103 when it merely combines familiar elements using known methods to achieve a predictable result. This principle was established in KSR, where the Supreme Court explained that “[t]he combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results.”

However, there are circumstances where a combination of known elements may still be deemed non-obvious if there is a significant gap between the known elements and their application in a particular system. For instance, in Fanduel, Inc. v. Interactive Games LLC, 966 F.3d 1334, 1342 (Fed. Cir. 2020), the Federal Circuit affirmed a decision by the Patent Trial and Appeal Board (PTAB) finding non-obviousness, reasoning that “[t]he Board reasonably identified a gap between the concept of a look-up table being well-known and the beneficial application of that concept to Carter’s gaming system.” This suggests that while a combination of known elements may often be obvious, a specific implementation that provides a distinct functional improvement may still be considered patentable.

Thus, while KSR sets a general framework for obviousness, cases like Fanduel demonstrate that a detailed analysis of how known elements are applied in a specific context is necessary in determining patentability.

Combining Equivalents Known for the Same Purpose: Combining two or more known compositions or elements that are each taught by the prior art for the same purpose is generally considered prima facie obvious and the result of common sense. This was established in In re Kerkhoven, 626 F.2d 846 (C.C.P.A. 1980), where the combination of known detergents was not patentable because the combination served the same purpose as each individual component.

Substituting Equivalents Known for the Same Purpose: Substituting one known equivalent for another in a prior art reference is considered obvious if the equivalency is recognized in the prior art. In re Ruff, 256 F.2d 590 (C.C.P.A. 1958) emphasized that the equivalency must be art-recognized and not based merely on the applicant's disclosure.

Combining Prior Art References According to Known Market Demand or Market Forces: A claimed combination of prior art elements may be considered obvious when there is a demonstrated market demand or design need that motivates a person of ordinary skill in the art to pursue a predictable solution. The Federal Circuit has recognized that market demand, rather than scientific literature, will drive design trends, and when a skilled artisan faces a design need or market pressure to solve a problem with a finite number of predictable solutions, there is good reason to explore known options within their technical grasp.

In Bayer Pharma AG v. Watson Laboratories, Inc., 874 F.3d 1316 (Fed. Cir. 2017), the Federal Circuit reversed a finding of non-obviousness, emphasizing that a skilled artisan motivated to develop vardenafil ODT (orally disintegrating tablet) would recognize a design need for its release profile. Given that an immediate-release formulation was one of only two available options, the court found that selecting such a formulation was an obvious choice. This reasoning aligns with cases where a marketplace incentive—such as the shift from mechanical to electronic pedals—drives innovation using known methods from the prior art.

Thus, the existence of a design need or market pressure, coupled with a limited number of predictable solutions, can provide a strong rationale for concluding that a claimed invention would have been obvious to a skilled artisan.

Obvious to Try: A claimed invention may be deemed obvious if it was merely "obvious to try" the claimed combination, particularly when there is a known motivation to solve a known problem and only a finite number of identified, predictable solutions exist. This principle, rooted in KSR's reasoning, established that obviousness is not confined to rigid application of the teaching-suggestion-motivation (TSM) test but can be demonstrated where a POSITA would have found it obvious to try a limited set of solutions. If prior art discloses only a small number of well-known and predictable alternatives for solving the same problem, the claimed invention may be obvious. For example, in Uber Techs., Inc. v. X One, Inc., 957 F.3d 1334 (Fed. Cir. 2020), the Federal Circuit reversed the PTAB’s finding of non-obviousness, concluding that prior art disclosed only two known and predictable solutions for location plotting: server-side plotting or terminal-side plotting, alongside a recognized need for this feature.

Elimination of a Step or Element and Its Function: Omitting a step or element from a prior art reference is often considered obvious if the function of that element is not necessary, as in Ex parte Wu, Proceeding No. 14124708 (P.T.A.B. Mar. 7, 2019) where omitting a salt from a corrosion inhibiting composition was deemed obvious because the salt’s function was irrelevant in certain environments. Conversely, when an element is omitted but its function is retained, this can be an indicium of non-obviousness, as in In re Edge, 359 F.2d 896 (C.C.P.A. 1966) where the omission of a protective layer did not change the function of the claimed invention, leading to a finding of non-obviousness.

Two Prior Art References Address the Same Problem with Related Approaches: A finding of motivation to combine prior art references is supported where the references address the same underlying problem and disclose solutions that are functionally equivalent. The Federal Circuit has upheld such findings in cases where the references demonstrate a common design need and provide interchangeable solutions.

In Philips Lighting N. Am. Corp. v. Wangs Alliance Corp., No. 17-2275 (Fed. Cir. Apr. 18, 2018) (non-precedential), the court affirmed the PTAB’s determination of a motivation to combine, emphasizing that the two references at issue (Hochstein and Hildebrand) presented only two obvious design choices. Both references solved the same problem in the same manner but differed in the positioning of the filter and current-conducting network. The court noted that the references demonstrated a demand for designs addressing the known problem, that Hildebrand’s configuration was a commonly accepted design that could be implemented in Hochstein, and that modifying Hochstein to incorporate Hildebrand’s design would not result in malfunction.

Known Technology in One Field Being Applied to Another Based on Design Incentives or Other Market Forces: A claimed invention may be deemed obvious if known work in one field of endeavor would prompt a POSITA to adapt or modify it for use in either the same or a different field, provided that the adaptation is predictable. This rationale is commonly applied by the USPTO and courts when assessing obviousness, particularly when design incentives or market forces drive such modifications. First, they must determine whether the prior art, whether from the same or a different field, includes an analogous device, method, or product. Next, they must identify whether there are design incentives or market forces that would have encouraged a skilled artisan to modify the prior art. Additionally, the differences between the claimed invention and the prior art must involve known variations or principles previously recognized in the field. Furthermore, a POSITA, considering the identified incentives or market forces, must have been able to implement the variation, and the modification must have been predictable. If any of these findings cannot be made, then this rationale cannot be used to support an obviousness rejection.

The Supreme Court’s decision in Dann v. Johnston, 425 U.S. 219 (1976), illustrates how this rationale is applied. In that case, the Court held that a computerized banking system was obvious because the applicant’s problem—providing a more detailed breakdown of transactions—was closely analogous to pre-existing methods of managing business transaction records. (Id. at 229, 189 USPQ at 261). A skilled artisan in data processing would have recognized that the known solutions in record-keeping could be applied in banking, and the modification required to implement the claimed system in a banking environment was within the ordinary skill level of the field. The Court ultimately concluded that the gap between the prior art and the claimed invention was not significant enough to make the invention nonobvious. This case exemplifies how courts assess whether an adaptation from one field to another is a predictable use of known technology, reinforcing the requirement that an invention must demonstrate more than a foreseeable application of prior knowledge to be patentable.

Automating a Manual Activity: Replacing a manual process with an automatic or mechanical means that accomplishes the same result is generally considered obvious. This principle was illustrated in In re Venner, where automating the release of a mold core was not sufficient to distinguish the invention from prior art.

Changes in Size, Shape, or Sequence of Adding Ingredients: Modifications related to size, shape, or the sequence of steps in a process are often not patentably distinct. In In re Rose, changing the size of a lumber package was not enough to differentiate it from prior art. Similarly, In re Dailey held that changes in the shape of a product are typically seen as obvious unless the new shape provides unexpected benefits.

Commonplace Efficiencies: Converting an existing device into a portable version, or making it integral, separable, or adjustable, is often considered obvious unless new and unexpected results are achieved. For example, in In re Lindberg, making a device portable was deemed obvious because it did not result in any new functionality.

Reversal, Duplication, or Rearrangement of Parts: The reversal, duplication, or rearrangement of parts in an invention is generally considered obvious unless it produces a novel result. In In re Gazda, merely reversing the movement of a clock mechanism was not enough to render the invention nonobvious.

Purifying an Old Product: Purifying a known product may be patentable if the purified form exhibits new and unexpected properties. However, merely achieving greater purity, without any functional or structural differences from the prior art product, does not confer patentability, as discussed in In re Bergstrom and Purdue Pharma v. Epic Pharma.

Aesthetic Design Changes: The court generally holds that aesthetic or ornamental changes that lack mechanical function are not patentably significant. For instance, in In re Seid, the court determined that purely ornamental aspects of a design do not distinguish the claimed invention from the prior art. However, the shape of a product can be critical if it results in a functional distinction, as seen in Ex parte Hilton, where the specific shape of potato chips was patentable over prior art that disclosed only french fries.

The Role of US Patent Office Personnel

The process of patent examination at the U.S. Patent and Trademark Office (USPTO) involves a review of submitted patent applications to determine whether the claimed invention meets the legal requirements for patentability. The examiner, who must be skilled in the relevant technical field, evaluates the application by comparing the claimed invention against the prior art—existing patents, publications, and publicly available information that predates the filing date of the application.

One of the key duties of a patent examiner is to assess whether the claimed invention is obvious to one of ordinary skill in the art at the relevant time, which typically refers to the effective filing date of the patent application. This involves determining whether the prior art reference disclosed any similar inventions or teachings that could render the claimed invention obvious. If a prior art reference disclosed all the elements of the claimed invention, or if a proposed modification to combine elements from different prior art disclosures would be obvious to one of ordinary skill in the art, the examiner may issue a rejection.

The concept of obviousness is central to patent examination. An invention is considered prima facie obvious if, at the relevant time, a person of ordinary skill in the art would have had a reasonable expectation of success in combining prior art teachings to arrive at the claimed invention. However, the prior art's mere disclosure of individual elements or teachings does not automatically render the claimed invention obvious. The examiner must also consider whether the combination of these elements would be logical and any evidence of secondary considerations asserted by the patent applicant, such as unexpected results, that could support patentability.

Additionally, the examiner must rely only on prior art that is analogous art—meaning that it is from the same field of endeavor or it is reasonably pertinent to the intended purpose of the invention. Only prior art that falls within this category may be prior to the obviousness inquiry. If the examiner concludes that the prior art is analogous and the claimed invention would have been obvious to a person of ordinary skill in the art, the examiner will issue an office action rejecting the claims based on obviousness.

Throughout this process, the examiner must provide a detailed explanation of their reasoning, ensuring that any rejection is well-supported by evidence. This allows the applicant to respond, providing arguments or amendments to overcome the rejection. The goal of patent examination is to ensure that only those inventions that are truly novel, non-obvious, and useful are granted patents, maintaining the integrity of the patent system.

Proposed Modification and Rational Underpinning

When assessing the obviousness of a claimed invention that involves combining prior art elements, the USPTO must provide a clear, rational underpinning for the proposed modification. This means that the examiner must articulate a reason why a person of ordinary skill in the art would have been motivated to combine these elements in the specific manner claimed. It’s not enough to merely assert that combining elements is obvious; the rationale must be grounded in evidence and logic, such as known industry trends, design incentives, or common problem-solving strategies within the relevant field.

For example, the examiner might refer to a problem recognized in the prior art that the proposed combination solves, or to a teaching or suggestion within the prior art that points to the combination. Additionally, the examiner must demonstrate that the combination would have had a reasonable expectation of success. This ensures that the proposed modification is not merely a theoretical possibility but a practical and logical step that a skilled artisan would have been likely to pursue. Without this detailed explanation, the rejection based on obviousness could lack the necessary foundation to withstand scrutiny during the patent examination process or in subsequent appeals.

Overcoming Obviousness Rejections

Challenge the Combination Rationale

A patent applicant can attack the rationale for combining prior art references. The examiner must provide a clear, rational underpinning for why a person of ordinary skill in the art would have been motivated to combine the elements of the prior art references to achieve the claimed invention. The applicant can argue that the examiner’s rationale is speculative, lacks sufficient reasoning, or fails to account for significant differences between the cited references and the claimed invention. The applicant may also argue that the proposed modification would not be obvious because it would not yield a predictable result, that there was no reasonable expectation of success in combining the prior art elements, or the prior art actually teaches away from the combination of references relied upon by the examiner.

Amend the Claims

The applicant may amend the claims to narrow their scope and distinguish them more clearly from the prior art. This might involve adding specific features or limitations that are not found in the prior art references, thereby making the invention patentable.

Demonstrate Unexpected Results

The applicant can provide evidence of unexpected results that the claimed invention achieves, which are not suggested or anticipated by the prior art. These results can demonstrate that the claimed invention goes beyond what a person of ordinary skill in the art would have expected when combining the prior art references. For example, if the invention offers superior performance, greater efficiency, or a new function not found in the prior art, these could be powerful arguments against obviousness.

Objective Evidence and Secondary Considerations

Objective evidence, such as commercial success, long-felt need, failure of others, and unexpected results, can be powerful tools in overcoming obviousness rejections. These indications of non-obviousness are referred to as secondary considerations for demonstrating patentability. Secondary considerations, also known as objective evidence, can counter a prima facie case of obviousness. Secondary considerations provide real-world context that can support the non-obviousness of a claimed invention.

Practical Implications and Strategies

Effective Filing Date and Prior Art References

The effective filing date of a patent application is critical in determining which prior art references can be relied upon. Only references that predate the effective filing date are considered prior art. Inventors and innovators should take early action after the development of a new invention to ensure their inventions are not rendered obvious by patent filings, product or service offerings or other public disclosures. Those who wait to file a patent application subject themselves to greater risk that a third party will beat them to the patent office or the marketplace.

Collect Evidence

The evidence submitted during prosecution can significantly influence the outcome of an obviousness rejection. Applicants should document and retain any testing data, field data, or other information about the performance and characteristics of technology. This information may provide compelling evidence of secondary considerations that can be used to counter prima facie obviousness rejection.

Get the Assistance of an Experienced Patent Attorney

Patent obviousness is a complicated concept that requires careful consideration of prior art, the level of skill in the art, and court decisions. A proper determination of obviousness hinges on a thorough and reasoned analysis, balancing legal standards with practical realities. If you are an entrepreneur or business that has developed new technologies, you should seek the assistance of experienced patent counsel. Our attorneys have decades of experience in the patent field. Contact us for a free consultation.

© 2025 Sierra IP Law, PC. The information provided herein does not constitute legal advice, but merely conveys general information that may be beneficial to the public, and should not be viewed as a substitute for legal consultation in a particular case.