Japanese Patent FAQs
Q.How long after the expiration of a Japanese patent can a patent owner still bring an infringement suit?
A patent owner can bring an infringement suit within three years from the time when he/she learns of the infringement and identifies the infringer. Additionally, the right to bring an infringement suit expires twenty years after the infringement begins.
Q.Are there any differences procedurally when an infringement suit is commenced after the expiration of a patent?
After the expiration of a patent, only damages can be demanded. That is, you cannot obtain an injunction after expiration.
Q.Does Japan recognize a provisional right to early damages before the patent is granted?
Yes. Regarding pre-grant damages, when a patent is granted, the patentee may exercise the right to demand compensation for an infringer’s acts carried out from the date the patent application was published in Japan to when the application was granted.
Q.What are the requirements for getting provisional rights?
To claim compensation for an infringer’s acts carried out before the issuance of the patent, a warning letter stating the contents of the claimed invention must be sent to an infringer while the application is pending and after the publication of the application.
Q.How much is the compensation for pre-grant damages (provisional right)?
The compensation will be the amount of royalties the patentee would have earned from the use of the claimed invention. It is not possible to claim lost profits.
Q.Is it possible to obtain an injunction to prohibit an infringer’s activity based on provisional rights?
No. The patent owner cannot enjoin an infringer from the activity based on provisional rights.
Q.How long can the patentee take advantage of provisional rights?
If a warning letter is sent to an infringer prior to the issuance of the patent, the patentee can seek compensation for provisional rights as late as three years from the date of registration of the patent.