The Patent Prosecution Process: How Patentability Is Examined

Once an invention has been developed to the point where patent protection is to be pursued, the first step is the filing of a patent application. This may take the form of a provisional application, a United States national application, or an international application under the Patent Cooperation Treaty (PCT). Regardless of the initial filing route, however, any application that seeks patent protection in the United States must ultimately proceed through the same examination process before the United States Patent and Trademark Office.

After a United States national application is filed, or a PCT application enters the United States national stage, the Patent Office reviews the application to determine whether all formal requirements have been satisfied and assigns the case to a patent examiner. The examiner then evaluates the claims against several established legal requirements for patentability.

The first of these is patent eligibility. Patent eligibility is distinct from patentability and must be satisfied before the remaining patentability requirements are considered. It serves as a threshold inquiry into whether the subject matter is of a type that may receive patent protection under statutory and judicial standards.

The examiner must also consider prior art requirements. In order to be patentable, a claimed invention must be new, meaning that it was not previously known or described before the effective filing date the application. In addition, it must be non-obvious, that is, it must be sufficiently different from what came before that it would not have been obvious to a person working in the relevant technological field.

A third set of requirements concerns the disclosure requirements of the application itself. Patent eligibility, novelty, and non-obviousness depend largely on the characteristics of the invention, whereas the disclosure requirements depend heavily on how well the invention is described in the application. These disclosure requirements include written description, enablement, utility, and best mode.

Under the written description requirement, the application must describe the invention sufficiently to demonstrate that the inventors were in possession of the complete invention as claimed. Under the enablement requirement, the application must disclose the invention in sufficient detail to allow a person of ordinary skill in the relevant technology to make and use the invention without undue experimentation.

The invention must also satisfy the requirement of utility, meaning that it must have a substantial and real-world use at the time the application is filed. That utility must either be apparent or adequately supported by the application. Finally, although the application must disclose the best mode known at the time of filing, current law does not permit a patent claim to be invalidated in litigation solely because the best mode requirement was not satisfied.

A further issue that may arise during examination is double patenting. Double patenting prevents an applicant from obtaining a second patent that would improperly duplicate or extend rights already granted in a related patent or application. It includes both statutory double patenting, which bars two claims to the same invention, and nonstatutory or obviousness-type double patenting, which bars claims that are not patentably distinct from earlier ones.

After reviewing the claims in light of these requirements, the examiner will typically issue a written communication indicating whether the claims are allowed or rejected. If claims are rejected, the Office Action will explain the reasons, and the applicant may respond by amending the claims, presenting arguments, or both. This process then continue through until an agreement is reached, the rejections are appealed, or the application is abandoned.

Patent prosecution is therefore not simply an administrative process, but a substantive and  iterative examination in which the scope and strength of a patent are shaped over time. Understanding how that process works provides an essential foundation for evaluating patentability and developing a sound patent strategy.

Disclaimer: This piece is provided for general informational purposes only and does not constitute legal advice. Patent issues are often complex and highly fact-specific, and no one should act on general information of this kind without consulting qualified patent counsel regarding the particular circumstances involved.