[Article / European Patents] Differences between Japanese and European patent systems requiring attention (Kazuhiro Nomura, Patent, September 2025)
Updated: 4 hours ago
Article information
Article type: Publication review
Categories: Patents / Europe
Main topics: Claim interpretation / Added matter / Numerical limitations and parameters / Patent drafting and translation
First published on this website: October 1, 2026
Display and classification checked: October 1, 2026 (not a revalidation of the legal analysis)
[Article / European Patents] Differences between Japanese and European patent systems requiring attention (Kazuhiro Nomura, Patent, September 2025)
1. Claims
① Independent claims
Japan: No limit.
Europe: In principle, one per category (Rule 43(2)). Multiple independent claims are disallowed except for cases such as interrelated products (plug and socket) or alternative solutions.
② Categories and use limitations
Japan: Products, methods and methods of producing products. Use limitations (e.g. for combating fatigue) are relatively strongly recognized.
Europe: Physical entities and activities. “Apparatus for ...” merely means “apparatus suitable for ...” and has weak limiting effect. Use claims for non-therapeutic use are therefore recommended.
③ Multiple-dependent-on-multiple-dependent claims
Japan: Restricted since April 2022 (violation of delegated ministerial ordinance requirements).
Europe: Unrestricted, but additional fees apply from the 16th claim.
④ Reference signs
Europe: Inserting drawing reference signs in parentheses in claims is strongly desired (Rule 43(7)).
2. Prior art and publication of earlier applications (self-collision and grace periods)
In Europe, one's own applications can be powerful grounds for rejection, requiring care in filing strategy.
3. Amendment restrictions (Europe's strict gold standard)
European amendment requirements are far stricter than Japan's: disclosure in the original specification must be direct and unambiguous.
Numerical limitations: In Europe, using undisclosed values (e.g. intermediate values of examples) as boundaries is very difficult. Combinations of preferred ranges should be expressly described in advance.
Disclaimers
Japan: Increasingly used to overcome lack of inventive step.
Europe: In principle, allowed only to restore novelty (e.g. avoid conflict with published earlier applications), not to overcome lack of inventive step (G1/03).
4. Parameter inventions
In Europe, specifying inventions through special parameters requires rigorous handling of measurement methods.
Measurement methods are often required in the claims themselves, not just the specification. Citing standards such as ISO without specifying the publication date (year) risks lack of clarity, given possible revisions.
5. Conclusions and proposals
When considering Europe based on a Japanese application:
① Given European independent-claim restrictions, file related inventions on the same day where possible.
② Given limited amendment flexibility, include varied numerical ranges and sets of multiple-dependent claim forms in the specification in advance.
③ To minimize loss-of-novelty risks from disclosure, treat European grace periods as nonexistent in principle.
Original article: https://lnkd.in/gnwj4Xhn
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Updates and corrections
Substantive corrections and additions are recorded separately from classification, related links and display changes.
October 1, 2026: First publication of the author's original LinkedIn text on this website. Article type, categories, topic tags, sources and consultation navigation added.
2026-10-01 | Display maintenance: added case references stated in the original or language-alternate metadata; not a revalidation of legal analysis.
2026-10-01 | Name notation: replaced verified Japanese-script personal names with Roman-letter forms in this English article and its navigation. Legal analysis and original publication date unchanged.
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