균등론 제5요건의 ‘특단의 사정’의 적용범위 ― ‘옥사롤사건’ 일본최고재판소판결의 분석과 시사점 ―

Abstract

This article is based on the judgment of the Supreme Court of Japan in the case of the “Maxacalcitol case”, and have considered the discussion of Korean law after introducing and analyzing Japan's discussion on materials and technologies that are already available at the time of patent application and are easily replaceable by the person skilled in the art (hereinafter referred to as “the same effect material at the time of filing”) in relation to the scope of application of the, “special circumstances”, the fifth requirement of the five requirements of the doctrine of equivalence. In patent infringement litigation, the defendant can dispute plaintiffs' alleged infringement by proving the “special circumstances” of the fifth requirement. In Korea and Japan, most of the time when the fifth requirement proves to be an issue is in the case where the behavior in the post-patent application process is evaluated, for example, when the scope of the patent claim is reduced due to the amendments in the patent application process. However, it is known that this issue, the same effect material at the time of filing, is reported to be unusual in foreign countries including Korea. The Court finding for the present case was that there is a case where an equal infringement is established for the same effect material at the time of filing, and the same effect material at the time of filing, which can be easily considered as a case corresponding to the “special circumstances”, is not specifically stated as a result of recognizing that there is a substitution of the composition described in the patent claims from an objective and external viewpoint. This judgment can be regarded as the establishment of a boundary line in which the disclosure function of the claim scope of the patent and the protection of the trust of a third party are emphasized and a judgment can be made by a third party. Predicting all forms of infringement at the time of filing a patent and requiring a complete patent claim is a socially ineffective solution from a prospective point of view. However, in Korea as in Japan, it is necessary to carefully formulate the appropriate patent claims through the search of prior art when filing a patent, and in particular, it is necessary to pay close attention to the same effect material at the time of filing taking the cue from the Court finding for the present case. According to the history in which the equal infringement has become recognized, or the Supreme Court precedent in Korea, if a case similar to the present case occurs in Korea, the Korean court is expected to make the same judgment as the judgment. The present court ruling is expected to be in helpful in Korea, which has similar legal systems to Japan, in relation to examining patent litigation practice, patent application practice and interpretation direction of Korean law.