TOPICS

Japanese Patent Case Summary: 2025 (Gyo-Ke) No. 10074 (Intellectual Property High Court (March 26, 2026)

“Method of Treating a Cutting Tool, and a Cutting Tool“

Overview:

In an appeal against an examiner’s decision of refusal, the JPO’s appeal board dismissed the amendment filed simultaneously with a request for an appeal, on the ground that it failed to satisfy the purpose requirement for amendments under Article 17-2(5) of the Japanese Patent Act, and rejected the appeal on the ground that the claimed invention before amendment lacks novelty over the cited invention. The Intellectual Property High Court upheld that appeal decision.

Issue addressed in this article:

The claimed invention recited before the amendment: “a method … wherein the cutting tool is subjected to shot peening at a temperature of or above 100° C, wherein the shot peening is performed on heated cutting tools”. The applicant revised the recitation to read: “a method… comprising heating the cutting tool to a temperature of 100°C or higher, and performing shot peening on the heated cutting tool”.

The issue is whether this revision qualifies as an amendment made for the purpose of “clarifying unclear statements” under Article 17-2(5)(iv) of the Patent Act.

Court’s reasoning:

(1) Article 17-2(5)(iv) of the Japanese Patent Act stipulates “clarification of an ambiguous description (only the amendment with respect to the matters mentioned in the grounds for the rejection concerned in the Notice of the Reasons for the Rejection)”. Accordingly, an amendment for “clarification of an ambiguous description” is permitted only when the applicant clarifies the relevant claim language with respect to the matters in the claims that the examiner has found to be unclear in the Notice of Reasons for Rejection.

The Court construes this provision as intending to prevent the applicant from amending, under the guise of “clarification of an unclear description,” matters that were not pointed out in the Notice of Reasons for Rejection, thereby altering portions that have already been examined and giving rise to new grounds for rejection. For this reason, “clarification of an unclear description” is interpreted as being limited to matters indicated in the grounds for rejection pointed out in the final notice of Reasons for Rejection.

In the present case, the Decision of Refusal concluded and reasoned that the application should be rejected for the grounds stated in the Notice of Reasons for Rejection, that is, lack of novelty and inventive step. The Notice did not point out that the description of the claimed invention was unclear.

Accordingly, the amendment at issue does not satisfy the requirements set forth in Article 17-2(5)(iv) of the Patent Act since it was not made with respect to the matters indicated in the grounds for rejection in the Notice of Reasons for Rejection, as required by the parenthetical clause of the above-mentioned provision.

(2) The term “ambiguous description” as used in Article 17-2(5)(iv) of the Patent Act refers to defective description, such as one whose meaning is obscure. In particular, when the claims involve an “ambiguous description”, (i) the wording of the claim itself is grammatically or logically unclear; (ii) the claim recitation is inconsistent or unreasonable in relation to other descriptions in the application; or (iii) although the wording of the claim is clear, the invention recited in the claims is not technically identified with sufficient precision and is therefore unclear. The “clarification” in this context means correcting unclear descriptions to clearly convey their intended meaning.

In light of the above, the Court then examined whether the claimed invention contains any “ambiguous description”. The claimed invention is clearly understood to specify that: (i) the object to be treated is a cutting tool including a substrate of cemented carbide or cermet; (ii) as the treatment applied to that cutting tool in (i), shot peening is performed at a temperature of or above 100°C; and (iii) the shot peening in (ii) is performed on the heated cutting tool. Accordingly, it should not be found to contain any “ambiguous description”.

The claimed invention as amended is understood to include that: (i)’ the object to be treated is a cutting tool including a substrate of cemented carbide or cermet; (ii)’ the method includes heating the cutting tool to a temperature of or above 100°C; and (iii)’ the method includes performing shot peening on the cutting tool heated in (ii).

Items (ii) and (iii) of the claimed invention are understood to include that the cutting tool is heated to a temperature of or above 100°C and shot peening is performed on the heated cutting tool. These are in substance the same as what items (ii)’ and (iii)’ of the claimed invention as amended mean.

Accordingly, replacing items (ii) and (iii) of the subject invention with items (ii)’ and (iii)’ of the claimed invention as amended does not “clarify” the originally intended meaning of the claim language. The amendment therefore does not constitute a “clarification.”

For these reasons, the amendment at issue is not regarded as having been made for the purpose of “clarification of ambiguous description”.

Comment:
In this case, the examiner found in the pre-appeal reconsideration report that the claimed invention as amended does not satisfy the independent patentability requirements. In response, the applicant submitted a written statement for a further amendment (hereinafter, the “amended invention proposed in the written statement”). This was seemingly the invention the applicant actually intended.

The present appeal decision held, as primary grounds, that (i) the amendment at issue does not comply with the purpose requirement, and the claimed invention lacks novelty. In the alternative, it also found that (ii) the claimed invention as amended does not meet the independent patentability requirements and further, (iii) the amended invention proposed in the written statement lacks inventive step, taking into account a newly cited reference.

A patent is not invalidated for involving an amendment that does not comply with the purpose requirement; accordingly, the JPO Examination Guidelines indicate that the compliance with the purpose requirement should not be assessed overly strictly. In practice as well, it is rare for an amendment to be dismissed solely for violating the purpose requirement. The fact that the appeal decision also addressed the above findings in (ii) and (iii) appears to reflect these circumstances.

However, the findings in (ii) and (iii) above are merely supplementary determinations provided as part of administrative service; even if the decision had been rendered solely on the basis of (i), that would not have made the decision unlawful.

In this case, had the applicant filed an appeal together with an admissible amendment (e.g., a narrowing amendment) from the outset with the content of the amended invention proposed in the written statement, a Notice of Reasons for Rejection based on the newly cited reference (Reference 2) would likely have been issued, and the applicant would have been given an opportunity to respond and further make amendments. However, by proceeding with an inadmissible amendment and a written statement, the applicant missed that opportunity.

Accordingly, the applicant needs to pay close attention to the purpose requirement for amendments along with other restrictions, when making amendments at stages where the purpose requirement applies, e.g., when a request for an appeal is filed.

Mitsuaki KOBIKI