이행불능 유형 구별 기준에 관한 비판적 고찰- 대법원 2014. 11. 13. 선고 2012다42666, 42673 판결을 중심으로 -

Abstract

Article 133 (3) of the Patent Act stipulates that when a patent invalidation trial is confirmed, the patent right shall be deemed to be invalid from the beginning. In other words, the invalidity of the patent has a retroactive effect. However, the Supreme Court found that even if a patent which is a subject of a patent license agreement is invalidated retrospectively, it is not possible to obtain the restitution of the royalty already paid by the agreement, as the performance under the license agreement is not regarded as an initial impossibility and a subsequent impossibility only. Before the Supreme Court decision concerned(the “Decision”), the majority of the theoretical opinions and the cases of German and Japan were in the same position with the Decision. In the United States, however, such discussions have been made in the view of the license estoppel and the binding power of a contract. The position of the Decision seems unreasonable: it is contrary to the Article of the Patent Act which acknowledges the retroactive effect of an invalid patent; overly conscious of the so-called “initial impossibility theory”, and on the other hand, recognizing that there is a realistic need to grant the binding power of a patent license agreement, it set a misleading distinction between an initial impossibility and a subsequent impossibility. The precedent have thoroughly pursued the ineffectiveness of the patent invalidation between the patentee and the infringer. It is inconsistent with this conventional attitude to restrict the retroactive effect only in relation to licensee. Rather, it could hinder the stability of the legal relationship through the conclusion of the patent license agreement. Moreover, the type of the impossibility is divided into an initial and a subsequent depending on when it became impossible as well as into a total and partial depending on its extent. An initial total impossibility, an initial partial impossibility, a subsequent total impossibility and a subsequent partial impossibility are different from each other in their treatment. However, as in some part of the ruling, it explained as if the case were about a partial impossibility, and on the contrary, it assumed as if the case were about a total impossibility. the Decision is appropriate neither in the classification of the impossibilities nor in the logical process.