What Is the Process for Appealing a Japan Patent Office (JPO) Trial Decision (Shinpan) to the Courts?

Japanese Attorney at Law - Bengoshi L.L.

• 11 min read

Decisions rendered by the Japan Patent Office (JPO) in its various trial proceedings (審判 - shinpan), such as invalidation trials, correction trials, or appeals against an examiner's final rejection of a patent application, are not necessarily the final word. Japanese patent law provides a crucial mechanism for judicial review of these administrative actions: the lawsuit to revoke a JPO trial decision (審決取消訴訟 - shinketsu torikeshi soshō). This specialized form of litigation allows aggrieved parties to challenge the legality and correctness of a JPO trial decision before the courts.

Understanding this appeal process is vital for any entity involved in JPO trial proceedings, as it represents the path to potentially overturning an unfavorable administrative outcome.

Introduction to JPO Trial Decisions and Judicial Review

The JPO is responsible for granting and administering patent rights, which includes conducting various quasi-judicial trial proceedings. These trials can be inter partes (between two or more opposing parties), such as:

  • Invalidation Trials (無効審判 - mukō shinpan): Where a third party challenges the validity of an issued patent.
  • Correction Trials (訂正審判 - teisei shinpan): Where a patentee seeks to correct errors or narrow the scope of their granted patent. (Note: Corrections can also be requested within an invalidation trial).

They can also be ex parte (between the applicant/patentee and the JPO), such as:

  • Trials against an Examiner's Decision of Rejection (拒絶査定不服審判 - kyozetsu satei fufuku shinpan): Where an applicant appeals a final rejection of their patent application by a JPO examiner.

If a party is dissatisfied with the final decision (審決 - shinketsu) rendered in one of these JPO trials, their primary recourse is to file a lawsuit to revoke that decision. Article 178(1) of the Japanese Patent Act grants exclusive jurisdiction over these lawsuits to the Tokyo High Court. In practice, these cases are handled by the Intellectual Property (IP) High Court, a specialized division within the Tokyo High Court established to deal with intellectual property matters.

Initiating a Lawsuit to Revoke a JPO Trial Decision (The Filing Stage)

Several key requirements must be met to properly initiate a lawsuit to revoke a JPO trial decision.

1. Appealable Decisions

The lawsuit is specifically for the revocation of a "trial decision" (shinketsu) or a ruling dismissing a request for a trial or retrial. Intermediate procedural rulings by the JPO are generally not directly appealable through this route.

2. Standing to Sue (Plaintiff's Standing - 原告適格 - genkoku tekikaku)

According to Article 178(2) of the Patent Act, the following parties generally have standing to file a lawsuit to revoke a JPO trial decision:

  • A party to the JPO trial (e.g., the applicant in an appeal against rejection, the patentee or the petitioner in an invalidation trial).
  • An intervenor who participated in the JPO trial.
  • A person whose application to intervene in the JPO trial was rejected.

Specific Considerations for Multiple Parties:

The issue of standing can become more complex when multiple parties were involved on one side of the JPO proceeding:

  • Multiple Requesters in an Invalidation Trial: If several parties jointly filed a request for an invalidation trial (and, for example, the trial decision was unfavorable to them), can one of these parties appeal to the IP High Court alone, or must all of them sue jointly? Since an invalidation request could often be filed individually, the prevailing view is that one of the joint requesters can typically file the revocation lawsuit alone. The IP High Court decision of December 18, 2018 (Hanrei Jihō No. 2412, p. 43, the "2D Code, etc." case or 「二次元コード等」事件) supports the notion that even if the JPO trial involved multiple opposing parties, a revocation lawsuit against the JPO decision might not need to name all of them as defendants if the interests are divisible.
  • Multiple Patentees (Co-owners) as Respondents in an Invalidation Trial: If a patent is co-owned and an invalidation trial decision is issued that adversely affects all co-owners (e.g., invalidating the patent), a critical question is whether one co-owner can appeal this decision alone, or if all co-owners must act jointly. The Supreme Court decision of February 22, 2002 (Minshu Vol. 56, No. 2, p. 348, the "ETNIES (trademark)" case or「ETNIES（商標）」事件), although a trademark case, laid down principles often considered applicable to patents. It suggested that for decisions adversely affecting a shared right, one co-owner can typically file an appeal alone. Such an appeal is seen as an act to preserve the common right, and a successful outcome (revocation of the adverse JPO decision) would benefit all co-owners. The legal relationship is considered to require a unified outcome for all co-owners.
  • Multiple Applicants (Co-applicants) in an Appeal Against an Examiner's Rejection: If a JPO trial decision upholds an examiner's final rejection of a patent application filed by co-applicants, the rule is generally stricter. Patent law requires co-applicants to act jointly for many crucial procedures related to the shared "right to obtain a patent," such as the initial filing (Article 38), withdrawal of the application (Article 14), and filing an appeal against an examiner's rejection (Article 132(3)). Consistent with this principle, the Supreme Court held on March 7, 1995 (Minshu Vol. 49, No. 3, p. 944, the "Magnetic Therapy Device" case or 「磁気治療器」事件), that all co-applicants must jointly file the lawsuit to revoke a JPO trial decision that maintained the rejection of their application.

3. Defendant(s) in the Lawsuit

  • In lawsuits appealing decisions from inter partes JPO trials (like invalidation trials or correction trials where an opposing party exists), the opposing party from the JPO trial is named as the defendant.
  • In lawsuits appealing decisions from ex parte JPO trials (like trials against an examiner's final rejection, where the JPO itself is the decision-maker without an opposing private party), the Commissioner of the JPO is formally named as the defendant. In practice, the JPO's legal team and the relevant appeal examiners will defend the JPO's decision.

4. Time Limit for Filing (出訴期間 - shusso kikan)

There is a strict statutory time limit for filing a lawsuit to revoke a JPO trial decision. Article 178(3) of the Patent Act specifies that the lawsuit must be filed within 30 days from the date on which a certified copy of the JPO trial decision was served on the party. This period is critical, and failure to meet it generally results in the dismissal of the lawsuit as untimely. For parties residing abroad or in remote locations, an additional period may be prescribed by the JPO Commissioner (Article 178(3) referencing Article 4).

Scope of Examination by the IP High Court (The Trial Stage)

Once a lawsuit is properly initiated, the IP High Court will review the challenged JPO trial decision. However, the scope of this judicial review is subject to important limitations.

1. Review Confined to the Legality of the JPO Decision

The primary function of the IP High Court in these lawsuits is to review the legality of the JPO's trial decision. It assesses whether the JPO correctly applied the relevant patent law and procedures and whether its factual findings were supported by the evidence presented during the JPO trial.

2. Restriction on New Issues and Evidence (Principle of Prior JPO Examination - 審判前置主義 - shinpan zenchi shugi)

A fundamental principle governing these lawsuits is that the IP High Court's review is generally limited to the same administrative record that was before the JPO appeal board. This means that parties usually cannot introduce entirely new grounds for invalidity, new prior art references, or substantial new factual evidence for the first time before the court if these were not raised and considered during the JPO trial proceedings.

This principle, sometimes referred to as shinpan zenchi shugi (implying prior examination by the JPO trial board), is rooted in several rationales:

  • Deference to JPO Expertise: The JPO is a specialized administrative agency with technical expertise in patent matters. It is considered appropriate for the JPO to have the first opportunity to examine all relevant technical arguments and evidence.
  • Efficiency and Orderly Procedure: Allowing new issues to be raised freely in court would undermine the JPO's role and could lead to protracted and inefficient proceedings.
  • Statutory Basis: While not a single explicit article, this principle is derived from the nature of the lawsuit as a review of an administrative decision and is supported by provisions like Article 178(6) which allows the court to revoke a decision if it violates laws or regulations (implying review of the JPO's adherence to its own scope).

The Supreme Court decision of March 10, 1976 (Minshu Vol. 30, No. 2, p. 79, the "Knitting Machine" case or 「メリヤス編機」事件), is a landmark authority establishing that new grounds of invalidity based on prior art not considered by the JPO cannot be newly asserted in the revocation lawsuit as reasons for overturning the JPO's decision.

3. Exceptions and Nuances to the Restriction on New Matters

While the general rule restricts new issues and evidence, there are important exceptions and nuances:

  • Evidence of Common General Knowledge (周知技術 - shūchi gijutsu or 慣用技術 - kan'yō gijutsu): Parties are generally permitted to submit evidence to establish the level of common general knowledge or conventional technical understanding of a Person of Ordinary Skill in the Art (PSITA) at the relevant time, even if such specific evidence (e.g., textbooks, handbooks) was not formally submitted to the JPO. This is because JPO examiners and appeal examiners are presumed to possess such knowledge, and it implicitly forms the background of their technical assessments. Presenting such evidence in court helps the judges (who may not have the same specialized technical background) understand the context. (See Supreme Court, January 24, 1980, Minshu Vol. 34, No. 1, p. 80, the "Food Packaging Container" case or 「食品包装容器」事件).
  • Arguing Different Legal Conclusions from the Same Factual Record: If the underlying factual basis (e.g., a specific prior art document) was properly before the JPO and considered in its decision, a party might be able to argue in court that the JPO drew the wrong legal conclusion from those facts. For example, if the JPO considered prior art reference X only in the context of inventive step (Article 29(2)), the appellant might argue that reference X actually destroys novelty (Article 29(1)) based on the same disclosure. This is generally permissible as it involves a re-evaluation of the legal effect of evidence already on record, rather than introducing entirely new factual grounds. (See, e.g., IP High Court, July 25, 2007, 2006 (Gyo-ke) 10247).
  • Limits on "Common General Knowledge" as a Guise for New Art: The exception for common general knowledge cannot be used as a backdoor to introduce what are effectively new prior art references or substantial new technical arguments that were not before the JPO. If the "common general knowledge" evidence effectively constitutes a new primary basis for challenging patentability that the JPO never had an opportunity to consider, it will likely be excluded. (See, e.g., Tokyo High Court, December 27, 1990, Mutaishū Vol. 22, No. 3, p. 879).

4. Prohibition of "Substitution of Reasons" by the JPO (in ex parte appeals)

In appeals against ex parte decisions (e.g., a JPO trial decision upholding an examiner's rejection of a patent application), where the JPO Commissioner is the defendant, the JPO cannot attempt to defend its decision in court by raising entirely new grounds for rejection or citing new prior art that was not part of its formal trial decision. This is known as the prohibition of "substitution of reasons" (理由の差し替え - riyū no sashikae). Allowing such substitution would be unfair to the applicant, as they would have been deprived of the opportunity to respond to these new reasons at the JPO level, for instance, by amending their claims or submitting counterarguments. (See Tokyo High Court, July 31, 1990, Mutaishū Vol. 22, No. 2, p. 457).

Effect of the IP High Court's Judgment (Post-Judgment Stage)

The judgment rendered by the IP High Court can either uphold the JPO's trial decision or revoke it.

1. Judgment Upholding the JPO Trial Decision (Dismissal of the Lawsuit)

If the IP High Court dismisses the plaintiff's lawsuit (請求棄却判決 - seikyū kikyaku hanketsu), it means the JPO's trial decision is affirmed. This decision becomes final and binding unless a further, limited appeal is successfully made to the Supreme Court (appeals to the Supreme Court in IP cases are generally restricted to significant errors of law or procedure).

  • Once final, a JPO decision upheld by the court (e.g., an invalidation decision or a decision dismissing an invalidation request) can have res judicata-like effects (一事不再理効 - ichiji fusairi kō) for the parties involved concerning the same facts and evidence, as per Article 167 of the Patent Act. This prevents them from re-litigating the same invalidity grounds based on the same evidence in a subsequent JPO trial.

2. Judgment Revoking the JPO Trial Decision (Revocation Judgment)

If the IP High Court finds that the JPO's trial decision was unlawful (e.g., based on an error of law, a clearly erroneous factual finding, or a procedural violation), it will issue a judgment revoking the decision (取消判決 - torikeshi hanketsu).

  • Remand to the JPO: Crucially, the IP High Court does not substitute its own decision on the merits of patentability or validity. It does not, for example, grant the patent itself or issue its own declaration of invalidity. Instead, upon revocation, the case is remanded to the JPO for further proceedings consistent with the court's judgment (Patent Act, Article 181(2)).
  • Binding Effect of the Revocation Judgment (拘束力 - kōsokuryoku): The IP High Court's judgment, including the essential reasons for its conclusion, is binding on the JPO in the subsequent remanded proceedings (Administrative Case Litigation Act, Article 33(1)). The JPO appeal board must reconsider the case in light of the court's ruling.
  • Scope of the Binding Effect: This is a complex area. The JPO is clearly bound not to repeat the specific error of law or fact identified by the court. However, the extent to which the JPO is precluded from reaching the same ultimate conclusion (e.g., still finding a patent invalid, or still rejecting an application) on remand using different reasoning or different evidence (if permissible to consider) has been subject to debate.
    • If the court revoked a JPO decision that found a patent invalid based on prior art A, the JPO on remand cannot simply reassert invalidity based on prior art A using the same flawed reasoning. However, it might be able to consider prior art B (if properly part of the record or newly admissible under specific rules) or even re-evaluate prior art A using a different line of reasoning that addresses the court's criticisms, provided this does not directly contradict the court's explicit findings.
    • The Supreme Court decision of April 28, 1992 (Minshu Vol. 46, No. 4, p. 245, the "High-Speed Barrel Polishing Method" case or 「高速旋回式バレル研磨法」事件) touched upon the binding effect, but its precise scope and how it applies in varied factual scenarios continue to be interpreted by the IP High Court. There's an ongoing tension between ensuring the JPO adheres to the court's specific ruling (the "judgment effect" theory or 判断効説 - handan kō setsu) and allowing the JPO some flexibility on remand versus a broader preclusive effect that might severely limit the JPO's options (the "preclusion effect" theory or 遮断効説 - shadan kō setsu).
  • Impact of Patent Correction (Amendment) During or After Judicial Review: If the patent claims at issue are corrected (e.g., narrowed) through a separate JPO correction procedure while the revocation lawsuit is pending or after a remand, this can significantly alter the subject matter of the dispute. If a JPO invalidation decision was based on the original claims, and those claims are subsequently validly corrected, the original JPO decision might become moot or its legal basis might change. In such cases, the court may revoke the original JPO decision and remand the case for the JPO to consider the validity of the corrected claims (this is sometimes referred to as the "automatic revocation" or 当然取消 - tōzen torikeshi principle, supported by Supreme Court precedents like the decision of March 9, 1999, Minshu Vol. 53, No. 3, p. 303, the "Large-Diameter Square Steel Pipe Manufacturing Method" case or 「大径角型鋼管の製造方法」事件).

Finality of the Lawsuit and Relationship with Retrial (再審 - saishin)

A final, unappealable judgment from the IP High Court (or the Supreme Court if an appeal is taken and decided) concludes the judicial review of that specific JPO trial decision. As mentioned earlier in the context of infringement litigation (Article 104-4 of the Patent Act), there are specific rules limiting the possibility of retrying a concluded court judgment based on a subsequent, different JPO administrative decision (e.g., a patent being invalidated by the JPO after an infringement court found it valid and infringed). The grounds for retrying a judgment in a lawsuit to revoke a JPO trial decision itself are primarily governed by the general provisions for retrial in the Code of Civil Procedure (e.g., discovery of conclusive new evidence that was previously unavailable, fraudulent acts by a party).

Conclusion

The lawsuit to revoke a JPO trial decision provides an essential avenue for judicial oversight of the JPO's quasi-judicial functions in patent matters. This process, governed by specific rules regarding standing, timeliness, and the scope of review, ensures that JPO decisions are legally sound and factually supported by the record before the agency. While the IP High Court generally defers to the JPO's technical expertise by restricting the introduction of entirely new issues or evidence on appeal, it rigorously examines the JPO's application of patent law and procedure. The interplay between the court's judgments and subsequent JPO proceedings on remand, particularly concerning the binding effect of judicial rulings and the impact of any intervening patent corrections, highlights the dynamic and often complex nature of patent dispute resolution in Japan.