Patent, Japan: Utilization of Oppositions and Invalidation Trials
The following is an overview of the utilization of patent oppositions and invalidation trials based on data reported in the Japan Patent Office Annual Report 2025 and the Patent Application and Related Statistics Bulletin.
1. Trends in Number of Cases
During 2024, there were 1,264 patent opposition cases in terms of individual rights (down 147 from the previous year), and 186 patent invalidation trial cases (up 102 from the previous year). Trends in the number of cases per month for patent opposition and patent invalidation trials since January 2021 are as shown below in FIG. 1. The number of patent opposition cases has continued to fluctuate. Patent invalidation trials have recorded busy months during which the number of cases has been high, as in November 2024, for example, where the number of cases was 46.
2. Trends in Average Trial Duration
Trends in average trial duration are as shown below in FIG. 2. Concerning invalidation trials, FIG. 2 shows trial durations for both patent invalidation trials and utility model invalidation trials. The average trial duration for an invalidation trial is slightly on the increase, standing at 15.1 months in 2024.
(Prepared using data from Source 2)
3. Trends in Trial Results
The trends in trial results are as follows. Concerning the difference between the proportion of decisions to revoke (decisions to revoke in part) in patent oppositions and the proportion of establishment of a request (establishment in part) for patent invalidation trials (i.e., difference between the proportion of patents revoked by patent oppositions and the proportion of patents invalidated by patent invalidation trials), the proportion of established requests for patent invalidation trials (including those established in part) is greater for every year. Furthermore, that difference exceeded 10 points in 2020, but was under 10 points in all other years.
Sources:
1. Japan Patent Office, “Patent Application and Related Statistics Bulletin”
2. Japan Patent Office, “ Japan Patent Office Annual Report 2025”
Etsuko NAGANO