Previously, I introduced a case in which a Canadian Federal Court admit to correct the inventor in the patent after its registration. On the other hand, is it possible to correct inventor in Japan? I would like to briefly discuss this below.
1. Before Registration
To answer the question of whether "inventor" of a patent can be corrected in Japan, the first point is what document "inventor" is listed in the patent application. In patent applications, "inventor is listed in the "Application Form". Therefore, the time when the "Application Form" can be corrected is the time when the inventor can be corrected.
On the other hand, certain restrictions are placed as shown in the following Handbook of Formalities relased from Japan Patent Office (JPO). The addition or deletion of inventor requires a reason and a written declaration, and the correction of certain errors also requires a reason and a written declaration. If you are unable to contact some of inventors after a certain period of time has passed since filing the application, you may find yourself in a situation where there is nothing you can do. It is important to keep in touch with the inventors listed in such patent application filed. In particular, such problems may become apparent after a long time has passed since the application was filed!
Handbook of Formalities 21．50
2. After Registration
The situation is different after the registration of the patent right. In this case, the description in the application is allowed to be corrected, but the application is not subject to correction in Correction Trial under JPO. At the moment, there seems to be no procedure at the JPO that allows for the correction of inventor after the registration ofthe patent right. In fact, in the Q&A of the JPO, it is stated that "After the registration of establishment, no amendment or correction of the inventor is allowed. Inventor's amendment is possible only while the application is pending before the JPO."
In conclusion, inventor's corrections can only be allowed in Japan when the patent application is pending before the JPO, and must be made in accordance with the Handbook of Formalities. It is important to note that the JPO does not currently allow inventor's corrections after the registration of a patent right.