[Article / Patents] Examination of the limits of claims with disclaimers (Kenji Tanaka et al., Patent, June 2025)
更新日：10月9日
Article information
Content type: Publication review
Categories: Patents
Issues: Disclaimer claims / Inventive step / Added matter / Clarity / Support requirement
First published on this site: 2026-10-03
Display and classification checked: 2026-10-03
[Article / Patents] Examination of the limits of claims with disclaimers (Kenji Tanaka et al., Patent, June 2025)
1. Analysis of JPO decision trends
A survey of FY2021 examination and appeal cases found that inventive-step arguments using disclaimers were unsuccessful in approximately 12% of cases.
2. Four categories in which inventive step is denied
① Design matters: The technical difference at the excluded boundary was small and within changes a skilled person could make as appropriate.
② New references: The initial reference was avoided, but another prior-art reference led to rejection.
③ Insufficient exclusion: The overlap with the cited invention was not completely excluded.
④ Not an essential feature of the reference: Only an optional feature was excluded, and omitting it was readily conceivable.
⇒ Claims excluding an essential feature of the primary cited invention are more likely to be recognized as inventive.
3-1. “Added matter” arising from disclaimers
Using boundary values absent from the original specification, such as values from a reference, risks introducing new technical matter.
3-2. “Lack of clarity” arising from disclaimers
Functional or abstract exclusions such as “not falling within ...” may be found to prevent unambiguous understanding of the scope.
3-3. “Lack of support or enablement” arising from disclaimers
The remaining scope after exclusion may lack concrete embodiments or substantiation in the specification.
4. Guidelines for using disclaimers
① What to exclude: Prioritize essential features of the primary reference—elements without which its problem cannot be solved.
② Drafting: Instead of copying unclear language from the reference, define the excluded scope clearly in light of common general technical knowledge.
③ Written arguments: Do not merely say that overlap was excluded. Explain logically how the exclusion makes the difference in technical concepts clear.
④ Preparation at filing: Treat disclaimers as a last resort. Include diverse subordinate concepts and alternative configurations in the original specification to preserve options for ordinary narrowing amendments.
Original article: https://lnkd.in/gD2CU3aM
Original source shown in the LinkedIn preview: https://jpaa-patent.info/patent/viewPdf/4660
Originally posted on LinkedIn: https://www.linkedin.com/feed/update/urn:li:activity:7511584835253989376/
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Update and correction history
Dated entries are added for corrections, supplements, classification, display, and related-article changes, separately from the first publication date.
2026-10-03: First publication on this site from the LinkedIn original.
Consultation guide by purpose: https://www.takaishihideki.com/en/single-post/consultation-guide-en
