균등 판단 시 공지기술의 참작

Abstract

After the Supreme Court 2017 Hu 424 decision and 2018 Da 267252 decision in 2019, it seems to be a clear trend that prior art is actively taken into account for determining infringement under the Doctrine of Equivalents (hereinafter ‘DOE’). However, an analysis of recent court decisions shows that the method of taking into account prior arts not described in the specification (the extrinsic prior art) in applying the equivalent in value test is different case by case. Therefore, it is confusing how to consider prior arts in the context of the equivalent in value test of the DOE. In order to solve this problem, it is necessary to reconsider what the object of equivalence determination is and the reason for taking into account the extrinsic prior art. The determination of equivalence is applied on an element-by-element basis and each requirement of the DOE is a means for assessing the difference between an element of the patented invention and the corresponding element of the accused product or process. Although the context of the invention as a whole should be considered in this determination, it should be noted that the determination of equivalence is ultimately an assessment of the difference. The reason that the extrinsic prior art is taken into account in applying the equivalent in value test is to objectively assess the value of the patented invention (the degree of contribution to technological advancement). The determination of equivalence should be applied on an element-by-element basis. The reason for objectively assessing the value of the patented invention is to define the range of equivalence according to the degree of contribution of the patented invention. Therefore, it is appropriate to consider the extrinsic prior art in determining whether to allow the extended protection beyond the literal wording for the element in question about equivalence and the scope of the extended protection. In addition, the extrinsic prior art should be considered only in the direction of narrowing the range of equivalence to provide legal certainty to third parties. The essence of the invention should be finally defined after taking into account the extrinsic prior art since both the specification and the extrinsic prior art, if any, need to be considered in this process. It is not appropriate to first determine the essence of the invention only with the specification and then apply two different tests when examining the identical effect, depending on whether or not the essence of the invention was publicly disclosed before the filing date. Rather, it is appropriate to first determine, based on the specification, the possibility of allowing the extended protection for the element in question about equivalence and then finally determine, in consideration of the extrinsic prior art, whether to allow the extended protection and, if so, the scope of the extended protection. Since the patent law protects the invention defined by the claim, not the underlying principles of the invention, it is important not to overly generalize the claimed solution. It is necessary to view the solution equivalent in value test not as a matter of yes or no, but as a matter of degree. In recent court decisions, there have been a lot of arguments from the parties that the essence of the invention was publicly disclosed before the filing date and equivalence determination tends to depend on whether or not the essence of the invention was publicly disclosed before the filing date. In order to solve this problem, the solution equivalent in value test should be applied on an element-by-element basis and the extrinsic prior art should be considered in defining the range of equivalence. In addition, applying two different tests when examining the identical effect, depending on whether or not the essence of the invention was publicly disclosed before the filing date, should be reconsidered.