Section 101 of the U.S. Patent Act sets forth the general requirements for patent protection in a single sentence:

Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvements thereof, may obtain a patent, subject to the conditions and requirements of this title.

Unfortunately, the actual test for patentability is a bit more complicated than this sentence suggests. Under U.S. patent law, an invention is patentable only if it meets the following four requirements, which are discussed in more detail below:

• The invention must be statutory (subject matter eligible)
• The invention must be new
• The invention must be useful

The invention must be non-obvious

Subject Matter Eligibility

Processes, machinery, objects of production, and substance compositions are patentable, according to Section 101 of the Patent Act. On the surface, this language appears to embrace every imaginable sort of invention. This is, to a considerable part, correct. The United States has one of the world’s broadest requirements for what constitutes patentable subject matter under this legislation. Physical device inventors often do not need to worry about whether their innovations are non-statutory. Certain innovations, however, are more likely to be contested as to whether they come under Section 101, such as software inventions and inventions about specific types of medical testing and diagnostics. Inventions that do not fulfill the Section 101 standards are regarded to fail the “subject matter eligibility” criterion for patent protection, and cannot get a valid US patent even if they meet the other patentability requirements (i.e., even if the invention is new, useful, and non-obvious).

The text of Section 101 defines four sorts of patentable inventions: methods, machines, products of the production, and substance compositions. If an innovation does not fall under one of these four categories, it cannot be patented. Data structures, for example, that are not claimed in conjunction with a computer or any sort of computer-readable media fall outside of these four categories. Nonfunctional descriptive content, such as music, literary works, and data compilations or arrangements, is also prohibited. It is therefore obvious that electromagnetic waves or signals do not fall into any of these categories and are hence not patentable. Finally, a claim to “software” that is not tied to a process or a physical machine (such as a computer or mobile device) would fall outside of the four statutory categories and would thus be unpatentable. To circumvent this dilemma, most experienced patent attorneys will never claim software in the abstract, but rather solely in the context of a computing machine or a process.

To be deemed a patentable type of invention, an invention must fit under one of these four legislative classifications and avoid a judicially imposed “exception” to the patentable subject matter. Recent case law has established three distinct exceptions: abstract notions, natural rules, and natural phenomena. The Supreme Court examined these three exclusions in Alice Corp. v. CLS Bank International. The “abstract notion” exclusion of patentable subject matter is especially significant for software, mobile-device applications, and Internet patents. Many observers believe that, following the Supreme Court’s explication of the abstract concept exemption, a huge percentage of software-related innovations are no longer patentable.

Novelty (Newness) Requirement

For an invention to be patentable, it must be considered unique or new. According to this condition, an invention cannot be patented if certain public disclosures of the invention have occurred. The laws that define whether a public disclosure has occurred are intricate and frequently necessitate a thorough examination of the facts and the law. However, the most significant condition is that an invention will not typically be patentable if:

• the invention was known to the public before the applicant filed for patent protection;
• the invention was described in a printed publication before the applicant filed for patent protection; or
• the invention was described in a published patent application or issued patent that was filed before the applicant filed for patent protection.

These restrictions are waived for disclosures made by the inventor within one year of filing the patent application. This implies that a patent application must be filed within one year after an inventor’s initial public disclosure or offer for the sale of an invention. This “statutory bar” is merciless, which means that an inventor who fails to file for patent protection on her new invention within the one-year grace period would forfeit all rights to patent protection on the innovation. Anything as benign as displaying the idea to acquaintances without any requirement of confidentiality might set off the one-year clock.

Although the United States provides the one-year grace period indicated above, most other nations do not. As a result, it is nearly always advisable to file a patent application before making the idea public. To facilitate foreign patent filings, most patent attorneys will work hard to file a patent application before any public release or announcement.

The America Invents Act dramatically altered the statute that outlines this uniqueness requirement under US law. Patent applications submitted on or before March 16, 2013, are subject to the prior version of the statute. Public disclosures made by someone less than one year before the patent application was submitted may not be barred under this older version of the revelation that was made after the applicant’s “invention” date.

Useful Requirement

The subject matter must be “useful,” which indicates that the innovation must have a beneficial purpose, according to patent law. In the context of computer and electrical technology, the utility criteria are readily accomplished in most circumstances. When seeking to patent a pharmaceutical or chemical compound, the condition is particularly crucial since it is vital to establish a practical or specific application for the new product.

Nonobviousness Requirement

If innovation is not identical to past items or methods (referred to as “prior art”), it is deemed new. The patent legislation, however, requires that an invention be a non-obvious advance over the prior art for it to be patentable. This assessment is achieved by determining whether the sought-after patentable innovation would have been evident “to a person of ordinary competence in the art to which the claimed invention pertains.” In other words, the invention is compared to the prior art, and whether the changes in the new invention would have been clear to a person of ordinary ability in the sort of technology employed in the invention is determined. The Act requires that the innovation be evident before the filing of the application.

As one might expect, determining whether a certain modification or improvement is “obvious” is one of the most difficult decisions in patent law. To make such a decision, a patent examiner would often study earlier patent papers to identify patents and published patent applications that are the most similar to the invention for which patent protection is sought. If all of the invention’s characteristics can be found in a single patent, the examiner will reject the patent as lacking originality (that is, it is the same as what was previously known and therefore is not new). If no patent has all of the characteristics, the examiner will combine two or more previous patents and look for all of the features in a combination of those prior patents. If the examiner finds such a combination, the invention will often be rejected as an obvious combination of components recognized in the previous art.

Rejections based on the combination of previous art references are quite prevalent in patent applications. To effectively utilize a combination of references to reject a patent application as apparent, the patent examiner must explain some basis for combining the references. Previously, patent attorneys might effectively argue against rejection by demonstrating that the inventors of the previous art references would not have considered combining their innovation with the other invention (s). The Supreme Court’s ruling in KSR International Co. v. Teleflex Inc. in 2007 made it simpler for an examiner to combine two references successfully in obvious denial. The Supreme Court specifically said that if combining two references gives only expected consequences, it would be clear to combine the two references—even if neither reference included an explicit reference to the other reference.