The Patent Act protects and uses inventions in order to encourage inventions and contribute to industrial development. Businesses, inventors, patent teams, investors, and researchers consult it when checking what counts as an invention, how applications are filed and examined, when patent rights arise, and what remedies or trials are available. This article covers selected core provisions of the Act and does not cover patent office fee schedules, claim drafting strategy, foreign filing strategy, or validity opinions for a specific invention.
Inventions, Implementation, and Patent Management
The general provisions define the technical subject matter and procedural frame for patents. Articles 1, 2, 3, 8, 17, and 17-2 are useful entry points before the substantive patentability rules.
Article 1 states the Act's purpose: to encourage inventions by protecting and utilizing inventions and thereby contribute to industrial development. Article 2 defines an Invention as the highly advanced creation of technical ideas using the laws of nature. Article 2 also defines a Patented Invention and defines Implementation of an invention by categories, including producing, using, assigning, exporting, importing, or offering to assign a product invention; using a process invention; and using, assigning, exporting, importing, or offering to assign a product made by a patented production process.
Article 3 sets rules for calculating periods under the Act, including exclusion of the first day in ordinary cases and extension when the last day falls on an administrative agency holiday. Article 8 requires a person without an address or residence in Japan to act through a Patent Administrator in Japan for patent procedures and litigation challenging administrative dispositions, except where Cabinet Order provides otherwise.
Article 17 allows correction of procedures while the case is pending before the Japan Patent Office, subject to detailed exceptions. Article 17-2 governs amendments to the description, claims, or drawings attached to an application. It allows amendments before transmittal of a certified copy of the examiner's decision to grant a patent, but limits amendments after a notice of reasons for refusal to the cases and purposes stated in that article.
Patentability and Applications
The Act then states who can obtain a patent and what the application must contain. Articles 29, 29-2, 30, 32, 36, 37, 38, 39, 41, and 43 are the main provisions for patentability, application content, unity, joint applications, prior applications, and priority.
Article 29 provides the central patentability rule. A person who has made an invention industrially applicable may obtain a patent, except for inventions publicly known in Japan or abroad, inventions publicly worked in Japan or abroad, inventions described in distributed publications or made publicly available through telecommunications lines before filing, and inventions that a person ordinarily skilled in the art could easily make based on those prior matters. Article 29-2 contains a prior-application publication rule for inventions described in an earlier application that is later published, subject to the article's conditions.
Article 30 provides exceptions to loss of novelty in specified cases where an invention became public before filing, if the statutory requirements are met. Article 32 excludes inventions likely to harm public order, morality, or public health from patentability. Article 36 requires a patent applicant to submit a written application stating prescribed matters and attach a description, claims, drawings where necessary, and an abstract. The description and claims must satisfy the disclosure and clarity requirements stated in Article 36.
Article 37 requires unity of invention, meaning the application must relate to one invention or a group of inventions satisfying the statutory technical relationship. Article 38 requires joint application where the right to obtain a patent is jointly owned. Article 39 provides the first-to-file rule for identical inventions. Article 41 provides domestic priority rules, and Article 43 provides procedures for priority claims under the Paris Convention.
Examination, Publication, and Grant
A patent application does not automatically proceed to substantive examination. Articles 48-2, 48-3, 49, 50, 51, 64, 66, and 67 explain the path from filing to publication, examination, and establishment of the patent right.
Article 48-2 states that examination of a patent application is conducted only after a request for examination. Article 48-3 allows any person to request examination within the statutory period after the filing date, and provides consequences when no request is made within that period. Article 49 requires an examiner to issue a decision of refusal where the application falls within listed refusal grounds, including lack of patentability, violation of claim or description requirements, or other statutory defects.
Article 50 requires the examiner to notify the applicant of reasons for refusal and give an opportunity to submit a written opinion before issuing a decision of refusal, except in specified cases. Article 51 requires a decision to grant a patent when no reasons for refusal are found. Article 64 requires publication of the application after the statutory period from filing, except in the cases stated there.
Article 66 states that a patent right is established by registration of its establishment. Article 67 sets the duration of a patent right at twenty years from the filing date of the patent application, while also providing special extension-registration systems in specified cases. These provisions separate application publication from the creation of an enforceable patent right.
Patent Rights, Licenses, and Infringement Remedies
After registration, the Act defines the exclusive right and remedies for infringement. Articles 68, 69, 77, 78, 79, 100, 101, 102, 103, and 104 are the main provisions for right scope, licenses, limitations, and civil enforcement.
Article 68 gives the patent right holder the exclusive right to work the Patented Invention as a business. Article 69 limits the effect of the patent right in specified cases, including working an invention for experiment or research and other listed acts. Article 77 allows creation of an Exclusive License, and Article 78 allows creation of a Non-exclusive License. Article 79 provides a prior-use Non-exclusive License where a person, without knowing the content of another's invention, made the invention independently or learned it from someone who did so and was working or preparing to work the invention in Japan at the time of the patent application.
Article 100 allows a patent right holder or Exclusive Licensee to demand cessation or prevention of infringement against a person infringing or likely to infringe the patent right or Exclusive License. The same article allows demand for destruction of infringing articles, removal of facilities used for infringement, or other measures necessary for preventing infringement.
Article 101 lists acts deemed to constitute infringement, including specified production, assignment, import, or possession of products used exclusively for working a patented invention. Article 102 provides rules for presuming or calculating damages, Article 103 presumes negligence of a person who infringes a patent right or Exclusive License, and Article 104 provides a production-process presumption for a product that was not publicly known in Japan before filing.
Opposition, Trials, and Appeals
The Patent Act includes post-grant and appeal procedures within the Japan Patent Office system. Articles 113, 121, 123, 126, 134-2, 167, 178, and 179 are key procedural landmarks.
Article 113 allows any person to file an opposition to grant of patent within the statutory period after publication of the patent gazette, on listed grounds such as lack of patentability or violation of disclosure requirements. Article 121 allows a person who received an examiner's decision of refusal to request a trial against the decision within the statutory period.
Article 123 provides for a trial for patent invalidation on listed grounds, including violation of patentability requirements, improper amendment, lack of entitlement, or treaty violation. Article 126 allows the patent right holder to request a trial for correction of the description, claims, or drawings for purposes such as claim restriction, correction of errors, or clarification of unclear statements, subject to the statutory limits.
Article 134-2 allows correction requests by a patentee in invalidation-trial proceedings. Article 167 limits repeated invalidation trials after a final and binding trial decision under the conditions stated there. Article 178 provides for actions to rescind trial decisions and specified rulings, and Article 179 states that the Commissioner of the Japan Patent Office is the defendant in specified rescission actions, while other cases use the parties stated in that article.