권리범위확인심판 및 침해소송에서의 공지기술의 항변 및 자유실시기술의 항변

This paper analyzes the “free-to-work technology defense”, which is often raised in patent right scope declaration trials. Regarding the defense, in practices, “prior art defense” being used with similar meaning, this paper differentiates that prior art defense is related to novelty determination and that free-to-work technology defense is related to inventive step determination. So far the Korean jurisprudence, without recognizing the difference between literal infringement determination and equivalents infringement determination, has applied the free-to-work technology defense to both determinations. With regard to it, relevant jurisprudence of Germany, Japan and the United States have been analyzed. Under such analysis, this paper finds that the free-to-work technology defense should not be allowed in literal infringement determination and be allowed only in equivalents infringement determination. In determining equivalents infringement, positive requirements and negative requirements are applied, and one of the negative requirements is free-to-work technology defense. The same theory may apply in an infringement lawsuit. Therefore, in an infringement lawsuit as well, the free-to-work technology defense (regarding inventive step) should not be allowed in determining literal infringement. Without reasonably necessary research, this paper provisionally proclaims that the prior art defense (regarding novelty) should also not be allowed in a patent right scope declaration trial or a patent infringement lawsuit. On the proclaim, further research is necessary.