An invention must be novel and non-obviousness over the prior art in order to be patentable. In brief, for an invention to be novel, it must be "new" in the sense that the exact invention is not in the prior art.1 For an invention to be non-obvious, the invention must go further than what would have been obvious to one of ordinary skill in the art when properly reviewing the relevant universe of prior art.2 A patentable invention must also satisfy other requirements, though the concepts of novelty and obviousness are of primary importance to the initial patentability analysis of any invention in any area of technology.3 What shall follow is a more detailed discussion of the non-obviousness requirement after first touching upon the requirement of novelty.

The Novelty Requirement and Prior Art

The novelty requirement essentially mandates that the claimed invention be new.4 An invention that is not new, i.e., that is "anticipated," is an invention for which a single item of prior art discloses all features of the invention. Section 102 of the Patent Act sets forth the basis for the novelty requirement for patents and patent applications and structures the first-to-invent nature of the United States patent system.5 More specifically, Section 102 identifies and seeks to define those things that are considered "prior art" against which the invention is to be compared for assessing compliance with the novelty requirement. The concepts captured by Section 102 can be described as twofold in the sense that (1) the prior art includes certain ideas and activities of someone other than the inventor herself, and (2) the prior art includes certain ideas and activities of the inventor herself. Generally speaking, prior art is that which was made available to the public by the inventor or another at a point in time specified by Section 102, or it may be that prior invention or possibility thereof by another, e.g., an earlier filing date. In many instances, prior art will simply be a patent or printed publication that was made public at a certain time in this or another country by a third party or the inventor herself. This may include brochures, journals, technical specs and other items made public at certain times. Other examples of prior art can include sales, offers for sale, and public uses of the invention that were made at certain times.6


Whereas the novelty standard disallows inventions identical to a prior art reference, obviousness typically requires a meaningful measure of distinction between the invention itself and the shoulders upon which the invention stands (i.e., the prior art). The principle of obviousness is codified in Section 103 of the Patent Act and generally compares the claimed invention with the overall state of the prior art. More specifically, Section 103 recites the following:

A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102 of this title, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains.7

As such, the obviousness standard requires the invention to have been non-obvious to one of "ordinary skill in the art to which the [subject matter of the invention] pertains" at the time of the invention.8

Section 103(b) sets forth the parameters of the obviousness requirement. The obviousness standard, in the simplest terms, requires a comparison of the state of the prior art with the claimed invention. The principle of obviousness allows for multiple references that may be relevant to the claimed invention, but that are not able to anticipate the claimed invention alone, to be viewed in light of each other and the teachings of each "combined." However, this begs the question of what would make a claimed invention obvious and what references are reasonable to combine. For example, in one early U.S. Supreme Court case, it was held that an inventor looking to solve a problem in the field of clay working would not look to prior art in the field of wood polishing.9

The U.S. Supreme Court ultimately set up the critical framework for making an obviousness analysis in the case of Graham v. John Deere.10 Under Graham, obviousness is a question of law based on underlying factual inquiries that look into the following: (1) the scope and content of the prior art; (2) the differences between the claimed invention and the prior art; (3) the level of ordinary skill in the pertinent art; and (4) other, secondary indicia of non-obviousness.11 Today, these inquiries remain the foundation of any obviousness analysis and/or determination.

In undertaking the Graham evaluation, the appropriateness of the prior art references and the combination thereof must be determined. One such relevant determination is whether the applied reference is "analogous art." This issue was addressed in In re Clay, which said that "[a]lthough § 103 does not, by its terms, define the ‘art to which [the] subject matter [sought to be patented] pertains,' this determination is frequently couched in terms of whether the art is analogous or not, i.e., whether the art is ‘too remote to be treated as prior art.'"12 The determination of analogous art was further described in Liposome Co. v. Vestar Inc., which stated, "the scope and content of the prior art includes references from those areas a person with ordinary skill in the art would look to in solving a particular problem."13

In the past, the Court of Appeals for the Federal Circuit had applied a rigid "teaching-suggestion-motivation" (TSM) test to determine if it was appropriate to combine elements of the various prior art references cited in an obviousness determination. Specifically, the TSM test required that prior art must contain a "teaching, suggestion or motivation" to combine those elements to arrive at the claimed invention.14

Today, the TSM test is no longer applied so rigidly. In 2007, the Supreme Court issued its opinion in KSR International Co. v. Teleflex Inc., critiquing the Federal Circuit's rigid use of the TSM test.15 The Supreme Court in KSR noted that the TSM test "captured a helpful insight" but was incompatible with Supreme Court precedent when applied as a "rigid and mandatory formula."16 As such, the Supreme Court determined that the TSM test was but one test and one possible approach for supporting an obviousness determination, and that the determination is not limited to one approach but is more flexible and capable of being demonstrated through various rationales.17

In response to the Supreme Court's decision in KSR, the United States Patent and Trademark Office (USPTO) developed six guidelines, in addition to the TSM test, for patent examiners to follow when assessing obviousness of a claimed invention. These guidelines were published in the Federal Register and were then incorporated into the USPTO's Manual of Patent Examination Procedure.18 The six guidelines are the following:

  1. The mere combination of known prior art elements may render a claim obvious when those elements are combined according to known methods to yield predictable results;
  2. An invention may be obvious when one known element is simply substituted for another to obtain predictable results;
  3. Merely using a known technique to improve similar devices (methods, or products) in the same way may be determinative in finding that a claim is obvious;
  4. Merely applying a known technique to a known device (method, or product) ready for improvement to yield predictable results may be determinative in finding that a claim is obvious;
  5. It may be obvious to try a particular combination of a claim where one is choosing from a finite number of identified, predictable solutions, with a reasonable expectation of success; and
  6. Known work in one field of endeavor may prompt variations of it for use in either the same field or a different one based on design incentives or other market forces, and such variations may be obvious if the variations would have been predictable to one of ordinary skill in the art.19

Importantly, any rationale employed must provide a link between the factual findings and the legal conclusion of obviousness, and any analysis supporting a rejection under 35 U.S.C. 103 must be explicitly set forth and explained by the examiner.20

By not denominating strict boundaries and rules for analyzing obviousness, the Supreme Court allowed the Federal Circuit to interpret the boundaries and determine what tests and approaches are appropriate in post-KSR cases. Since the 2007 decision in KSR, the Federal Circuit has provided several examples for analyzing obviousness. As such, the USPTO revisited the issue and promulgated a "2010 KSR Guidelines Update" that puts forward pertinent example cases, each providing guidance and clarification to the obviousness inquiry.21

The 2010 KSR Guidelines Update corresponds directly with three of the rationales identified in the 2007 KSR Guidelines — combining prior art elements, substituting one known element for another, and the obvious-to-try rationale —and further focuses on issues concerning the consideration of evidence during prosecution.22 Regarding the rationale of combining prior art elements, the 2010 KSR Guidelines Update states that "even though the components are known, the combining step is technically feasible, and the result is predictable, the claimed invention may nevertheless be nonobvious when the combining step involves such additional effort that no one of ordinary skill would have undertaken it without a recognized reason to do so."23 Regarding the rationale of substituting one known element for another, the Guidelines Update states that the purported inventions may be obvious "when one of ordinary skill in the art would have been technologically capable of making the substitution, and the result obtained would have been predictable."24 Regarding the obvious-to-try rationale, the Guidelines Update states that this rationale "must always be undertaken in the context of the subject matter in question, ‘including the characteristics of the science or technology, its state of advance, the nature of the known choices, the specificity or generality of the prior art, and the predictability of results in the area of interest.'"25 The Guidelines Update additionally discusses some of the Federal Circuit case law addressing evidentiary considerations and states that the "evidence should not be considered simply for its ‘knockdown' value; rather, all evidence must be reweighed to determine whether the claims are nonobvious."26

The obviousness inquiry is no longer strictly limited to the rigid TSM approach, but is now an ever-evolving determination that the Federal Circuit can mold. It is undoubted that future Federal Circuit decisions will provide further guidance and rationales. Nonetheless, it is vital to consider the Guidelines provided by the USPTO to their examining personnel. This will allow for appropriate claims and arguments to be presented that may place an application in a condition more likely to be allowed.