On June 4, 2025, the 54th Subcommittee on the Patent System, part of the Intellectual Property Committee of Japan’s Industrial Structure Council, convened to discuss key issues related to artificial intelligence (AI) and patent law.
As AI technology continues to evolve, its use in research and development is expanding rapidly. AI tools are now capable of producing large volumes of technical outputs in short periods of time, raising questions about how such results should be treated under the current patent system.
The Subcommittee identified three areas that warrant early consideration:
Patentable Subject Matter
Under Article 2 of the Japanese Patent Act, an “invention” is defined as a “highly advanced creation of technical ideas utilizing natural laws.”
Currently, even if a natural person uses AI tools to generate an invention, such an output can still qualify as a patentable invention—provided it meets the legal definition. However, the increasing capabilities of AI are beginning to substitute certain parts of the inventive process, challenging traditional assumptions.
In the near future, AI may become more deeply involved in ideation, problem-solving, and solution design. As a result, the degree of human contribution in the inventive process may diminish. There is growing need to clarify whether AI-assisted inventions, or even so-called autonomous AI-generated inventions, should still be considered “inventions” under the law.
Inventorship
While Japan’s Patent Act does not explicitly define “inventor,” case law indicates that an inventor must be a natural person who makes a creative contribution to the technical features of the invention.
When filing a patent application for an AI-assisted invention, it is unclear who qualifies as the inventor:
- the developer of the AI system (e.g., the one who selected training data),
- the user of the AI tool (e.g., who provided prompts), or
- the individual who validated the results.
If no human is found to have creatively contributed to the technical features of the invention, the application could be rejected for lack of a legitimate inventor under Article 36. Ironically, the more intensively AI is used, the more likely it becomes that no human inventor can be identified, potentially leading to the rejection of applications despite genuine innovation.
This raises a broader policy question: Should the definition of inventorship be revisited to ensure that creators who actively utilize AI still receive proper legal protection and incentives?
Use of AI-Generated Publications as Prior Art
AI now enables the rapid generation and publication of large volumes of technical content. However, some of this content may be unclear, unverifiable, or even fictitious. If such AI-generated documents are routinely treated as prior art, they may be used to reject otherwise valid applications—discouraging innovation.
To address this, the Subcommittee stressed the importance of clarifying whether AI-generated documents should qualify as prior art, and what standards they must meet in order to be used for assessing novelty or inventive step.
Conclusion
With AI becoming an integral part of innovation, Japan’s patent system faces the urgent need to review how such technologies intersect with traditional legal concepts like “invention,” “inventor,” and “prior art.” The discussions from the June 2025 Subcommittee meeting highlight the importance of developing clear and predictable rules to maintain legal certainty and support future R&D efforts involving AI.
