특허 분야에서의 부당이득반환 법리의 적용

The doctrine of restitution of unjust enrichment is stipulated as a general provision under Articles 741 through 749 of the Korean Civil Act, but, there are only very few precedents accumulated and discussions held relating to application of the same in patent cases. This appears to be attributable to the fact that patent infringements are regarded as a tort according to the current Patent Act that provides for the presumption of negligence rule and the rule of calculating damages. However, in supplementing the basic principles that underlie contract law or tort law, the restitution of unjust enrichment doctrine may be applicable in such patent cases as where: (i) a patent is invalidated following a patent holder’s execution of a preservative measure; (ii) it is difficult to hold a licensee liable for patent enforcement during a licensing negotiation; and (iii) a licensing contract becomes null and void upon a licensee’s payment of license fee. In view of the fact that the doctrine of restitution of unjust enrichment is not widely applied in practice, this paper sheds light on ways that said doctrine may be applied in diverse patent cases. The research methodology focuses on the legal relationship between an inventor and patent holder centering on the right to claim transfer of a patent right, and between a patent holder and licensee centering on the right to claim restitution of unjust enrichment. The latter part of this paper discusses Supreme Court Decision 2012Da42666, 42673 Decided November 13, 2014. The Court ruled that a patent holder was not obliged to return a license fee upon invalidation of patent. Such decision, however, may encourage unlawful patent infringements as it is more economically reasonable compared to concluding a licensing agreement for those wishing to enforce a patent.