특허권 침해에 대한 손해배상액 산정: 미국의 기여도(apportionment ratio) 법리

The apportionment principle has evolved when calculating damages for patent infringement. In other words, the apportionment ratio has been considered as being more and more important, especially in the context of the multi-component product. The proper measure of damages for patent infringement has been in controversy and continues to be a contentious legal issue in the U.S. under the recognition over high damages awards for patent infringement. In response to that concern, the U.S. Court of Appeals for the Federal Circuit (CAFC) has repeatedly turned its attention to the apportionment principle when calculating damages and has issued decisions to give some guidelines regarding the challenging issue of how one should estimate the value of the asserted patented invention. Thus, it is necessary to scrutinize the apportionment jurisprudence of the U.S. in detail. This article first attempts to describe in detail the two most important apportionment principles in the U.S., which are the Entire Market Value Rule (EMVR) and the Smallest Salable Patent-Practicing Unit (SSPPU) approach. Then, it will analyze the relationship between the EMVR and the application of the apportionment ratio when calculating damages based on the value of the entire infringing product. Additionally, this article will attempt to explain the relationship between the SSPPU approach and the application of the apportionment ratio, and will suggest that the value of the patented invention may be theoretically higher than the entire value of the identified SSPPU, depending on the situation of each case. This article coins such rule as “SSPPU expansion rule”. Importantly, this suggestion may be for the first time. Lastly, this article addresses some cases, which are dealing with the challenging issue of how to apply the apportionment ratio when calculating damages in the context of lost profits damages, infringer’s profits and reasonable royalty damages.