The appeal is dismissed.

The costs of appeal are assessed against the Plaintiff.

The grounds of appeal are examined.

1. Regarding ground of appeal No. 2

A. (1) The main sentence of Article 133(1) of the former Patent Act (amended by Act No. 11654, Mar. 22, 2013; hereinafter the same) provides that “an interested party or examiner may file a petition for an invalidation trial in any of the following cases.”

The term "interested person" refers to a person who has a direct and realistic interest in the extinguishment of a patent right because the existence of the right to the patented invention in question has suffered or is likely to suffer any legal disadvantage due to the existence of the right to the patented invention, and includes a person who manufactures and sells, or manufactures and sells, the same kind of product as

According to such legal principles, barring any special circumstance, a patent licensee’s interest in filing a petition for a trial on invalidation is not deemed extinguished solely on the ground that the licensee is not or is not likely to be contested by the patentee.

(2) The reasons are as follows.

In general, the licensee of a patent is subject to various restrictions, such as the payment of a license fee or the scope of license. As such, the licensee may escape from such restrictions by obtaining a trial decision on invalidation of a patent through an invalidation trial.

In addition, even if there are grounds for invalidation of a patent, the patent right remains valid until a final and conclusive decision on invalidation is rendered, and its existence cannot be denied without permission, and a considerable time and cost is required until a final and conclusive decision on invalidation is rendered even if a petition is filed for a trial for invalidation

For this reason, even a person who wants to implement a patent without being granted a license may first obtain a license from a patentee and implement a patented invention at a later stage. Therefore, he/she would not dispute the invalidity of a patent on the ground that he/she has been granted a license.