Are You Aware of Patent Claims Description Requirements in Japan?

This article addresses – by example of an actual utility model dispute case – the handling of “Claims Scope Description Requirements” in Japanese patent practices, for both plaintiff (challenger / demandant) and defendant (patent holder / demandee) regarding the “Requirements For Description” in Japan Patent Office (JPO) trials of invalidation of registration and in the IP High Court.

An SME Client Utility Model Example

An SME (small and medium-sized enterprise) in China had a utility model registration in Japan, and issued a patent damage warning to a large Japanese company. The Japanese company responded by attempting to invalidate the utility model registration, and we were appointed as agent for the SME at this stage. Generally, under such circumstances, the demandant files for an Invalidation Trial in the Japan Patent Office.

The allowable basis for invalidation is “violation of the requirements for describing the claims” (Article 5, Paragraph 6, Item 1 of the Utility Model Law). The specific reason for invalidation argued by the Japanese company side was “The claims only describe the composition, and it is unclear how the functions, actions, and effects can be achieved, and the description is not clear. So it is illegal.”

As the agent for the SME demandee, we chose to fight the large Japanese company, and dispute their claim. In the trial for invalidation at the JPO, a trial decision to dismiss the appeal was issued: the demandee won.

The company, filed an appeal with the IP High Court which was dismissed. They, the demandant, then filed an appeal with the Supreme Court which was also dismissed: the final conclusion being the SME, the demandee, winning case and confirming the validity of their patent.

Background specifics are that the utility model registration is a fitness device, a “vibrator that gives minute vibrations to the user’s body”, and only the components of the vibrator are included in the claims for utility model registration. The components were described, but not how the components cooperated with each other to generate the vibrations. However, there was a detailed description in that regard in the specification. Therefore, those skilled in the art can understand the relationship between the constituent requirements described in the claims by referring to the specification.

A Final Thought

Regarding this point, in the JPO’s “Patent Examination Standards” and also in judgments of past courts, “whether or not they can be clearly understood when referring to the specification and common general technical knowledge” are used as criteria for determining the clarity requirement. Our counter argument was developed based on this, and was accepted by the JPO and the court.

In effect, in this case we were able to win with a grammatical counterargument. It is a long and costly process to reach a Supreme Court decision, however, from a patent practitioner’s perspective, it is probable that such invalidation demands can be blocked as long as the function is well described in the claim of the utility model registration.

From the viewpoint of protecting SMEs, the critical importance of describing the claims at the time of filing must be recognized.


By Takaaki Kimura

Managing Partner and Patent Attorney with over thirty-five years of IP law experience.