Tokyo District Court, Case No. 2024 (Wa) 70460

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Article information

Article type: Case note

Display and classification checked: 2026-09-30

Categories: Patents

Topics: Claim interpretation / Doctrine of equivalents

Published on this website: 2026-09-29

Tokyo District Court, Case No. 2024 (Wa) 70460

[Widening structure for a shield tunnel] (Presiding Judge Nakajima)

*Claim requirements not satisfied (the doctrine of equivalents also not established).

In interpreting the claim wording "filling a temporary filling case with filling material," the court held that "temporary filling case" means a container to be "filled" with "filling material," while "filling material" means raw material for filling gaps or voids. The "temporary filling case" and "filling material" are therefore physically separate and independent members.

The protective piece of the product at issue is a single member integrated by welding, so it cannot be said to possess configurations corresponding to a "temporary filling case" and "filling material."

(Quoted wording is translated.)

https://lnkd.in/gptU677n

https://lnkd.in/g-A_GyWn

https://lnkd.in/gDWmUbvi

hanrei-pdf-95403.pdf — courts.go.jp

Originally posted on LinkedIn: https://www.linkedin.com/feed/update/urn:li:activity:7510141686673498112/

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Updates and corrections

This log starts on 30 September 2026. Display and classification checks are distinct from a review of the legal analysis.

2026-09-30 — Presentation update: added the article type, this change log and a link to consultation options. The existing article text was preserved.

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