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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
Patent Index | Patent Applications
Subject Matter Eligiblity
Section 101 of the Patent Act states that processes, machines, articles of manufacture, and compositions of matter are patentable. At first blush, this wording appears to cover every conceivable type of invention. To a large extent, this is true. Under this statute, the United States has one of the broadest standards for what constitutes patentable subject matter in the entire world. Inventors of physical devices generally do not have to worry about whether their inventions are non-statutory. However, there are certain inventions that are more likely to be challenged as to whether they fall within Section 101, including software inventions and inventions relating to certain types of medical tests and diagnostics. Inventions that do not meet the requirements of Section 101 are considered to fail the "subject matter eligiblity" requirement for patent protection, and cannot receive a valid US patent even if they meet the other requirements for patentability (i.e., even if the invention is new, useful, and non-obvious). See 35 U.S.C. 101; and MPEP Sections 2104 and 2106
The language of Section 101 identifies four types of inventions that are patentable, namely processes, machines, articles of manufacture, and compositions of matter. If an invention does not fall within one of these four categories, the invention is not patentable. For example, data structures that are not claimed in combination with a computer or some type of computer-readable media are clearly outside of these four categories. So is nonfunctional descriptive material, such as music, literary works, and compilations or arrangements of data. It is also clear that electromagnetic waves or signals do not fit into any of these categories, and therefore are 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 also fall outside the four statutory categories and therefore would not be patentable. In order to avoid this problem, most experienced patent attorneys will take care never to claim software in the abstract, but will only claim software in the context of a computing machine or a process. See MPEP Section 2106
In addition to falling within one of these four statutory classes, an invention must also avoid a judicially created "exception" to patentable subject matter if it is to be considered a patentable type of invention. Recent case law has identified three different exceptions, namely abstract ideas, laws of nature, and natural phenomenon. The Supreme Court in Alice Corp. v. CLS Bank International analyzed these three exceptions in some detail. The "abstract idea" exception to patentable subject matter is particularly important for patents relating to software, mobile-device apps, and the Internet. Many observers are of the opinion that a large precentage of software-related inventions are no longer patentable after the Supreme Court's explanation of the abstract idea exception. See BitLaw's Section 101 Index and MPEP Section 2106 for more details
Novelty (Newness) Requirement
In order for an invention to be patentable, the invention must be considered to be new or novel. This novelty requirement states that an invention cannot be patented if certain public disclosures of the invention have been made. The statute that explains when a public disclosure has been made (35 U.S.C. Section 102) is complicated and often requires a detailed analysis of the facts and the law. The most important rule, however, is that an invention will not normally 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.
There is an exception to these requirements for disclosures made by the inventor less than one year before the patent application was filed. This means that there is a one year period after the first public disclosure or offer for sale of an invention by an inventor during which a patent application must be filed. This "statutory bar" is unforgiving, which means that an inventor who does not file for patent protection on her new invention within this one year grace period will lose all right to obtain patent protection on the invention. In fact, it is possible that this one-year clock may start "ticking" by something as innocuous as showing the invention to friends without any obligation of confidentiality. See 35 U.S.C. 101 and MPEP Section 2153.01(a)
Although the United States grants the one year grace period described above, most other countries do not grant such a period. Therefore, it is almost always preferable to file a patent application before any public disclosure of the invention. Most patent attorneys will try diligently to file a patent application prior to any public release or announcement in order to allow international patent filings.
The statute that describes this novelty requirement under U.S. law was significantly revised by the America Invents Act. Patent applications that were filed on or before March 16, 2013 fall under the earlier version of the statue. Under this earlier version, public disclosures made by another less than one year before the patent application was filed may not bar an application if the disclosure was made after the applicant's "invention" date. See 35 U.S.C. 102
The patent law specifies that the subject matter must be "useful." This means that the invention must have a useful purpose. In most cases, the usefulness requirement is easily met in the context of computer and electronic technologies. The requirement is more important when attempting to patent a pharmaceutical or chemical compound, as it is necessary to specify a practical or specific utility for the new compound. See MPEP Section 2107
If an invention is not exactly the same as prior products or processes (which are referred to as the "prior art"), then it is considered novel. However, in order for an invention to be patentable, the patent statute also requires that the invention be a non-obvious improvement over the prior art (35 U.S.C. Section 103). This determination is made by deciding whether the invention sought to be patented would have been obvious "to a person having ordinary skill in the art to which the claimed invention pertains." In other words, the invention is compared to the prior art and a determination is made whether the differences in the new invention would have been obvious to a person having ordinary skill in the type of technology used in the invention. The statute requires that the invention be obvious at a time before the application was filed. See 35 U.S.C. 103 and MPEP Section 2141
As can be imagined, the determination of whether a particular change or improvement is "obvious" is one of the most difficult determinations in patent law. In order to make such a determination, an examiner in the patent office will normally review previous patent documents to find those patents and published patent applications that are closest to the invention for which patent protection is sought. If all the features of the invention can be found in a single patent, the examiner will reject the patent as lacking novelty (that is, it is exactly the same as what was previously known and therefore is not new). If no patent contains all of the features, the examiner will attempt to combine two or more prior patents, and attempt to find all of the features in a combination of those prior patents. If the examiner is successful in finding such a combination, the examiner will generally reject the invention as an obvious combination of items known in the prior art. See MPEP Section 2143.01
Rejections made by combining prior art references are very common in patent applications (see BitLaw's discussion on patent prosecution). For a combination of references to be successfully used to reject a patent application as obvious, the patent examiner must provide some reason to combine the references. In the past, patent attorneys could successfully argue against a rejection by proving that the inventors of the prior art references would not have looked to combine their invention with the other invention(s). The Supreme Court's 2007 decision in KSR International Co. v. Teleflex Inc. made it easier for an examiner to successfully combine two references together in an obviousness rejection. In particular, the Supreme Court said if the combination of two references yields only predictable results, it would be obvious to combine those two references--even if neither reference contained an explicit reference that it could have been combined with the other reference. See MPEP Section 2143