Recent Changes in the Handling of “Disclaimer Claims” in Japan－ Impact on Addition of New Matter, Inventive Step, Clarity, Prior User’s Rights, etc.－
The article “Recent Changes in the Handling of Disclaimer Claims in Japan: Impact on Addition of New Matter, Inventive Step, Clarity, Prior User’s Rights, etc.”, co-authored by Mr. Nobuyuki Kashiwa and Mr. Shoji Nieda, was published in the official bulletin of AIPPI Japan Journal (Vol. 51 No. 5 2026).
This article explains operational changes in the handling of disclaimer claims in Japanese patent practice and their practical implications. While taking into account the legal background, such as the Solder Resist case, the authors analyze the background of system changes and recent judicial precedents from various perspectives such as inventive step, clarity, prior user's rights, and international harmonization. The article also comprehensively presents practical countermeasures recommended to applicants, patent owners, and third parties going forward.