등록상표의 구성 중 등록 이후 사용에 의한 식별력을 취득한 부분의 효력(대상판결: 대법원 2014. 3. 20. 선고 2011후3698 전원합의체 판결)

If a registered trademark acquires distinctiveness through use after registration, the issue of validity of a trademark needs to be differently approached in deciding nullity of its registration and in determining whether a certain mark is similar to the registered trademark. In deciding nullity of its registration, if the trademark did not have distinctiveness at all at registration decision, even though it acquired distinctiveness through use after registration, its registration should be nullified. If a registered trademark has distinctiveness as a whole at the registration decision, but its elements devoid of distinctiveness acquired distinctiveness through use after the registration, the registered trademark has no ground for nullity of registration and thus the trademark registration is effective. But whether a mark is similar to the registered trademark should be determined based on whether the similarity between marks creates a likelihood of confusion or mistake to consumers as to origin of products, so the presence and intensity of the registered trademark's distinctiveness are important considerations in the decision. Since the presence and intensity of a mark's distinctiveness is relative and changeable depending on transaction circumstances, etc., the issue of whether there is similarity between marks should be determined at the same criterion time of deciding the presence of similarity between marks. It means that at trial to confirm scope of right the presence and intensity of the trademark's distinctiveness should be decided at the time of the trial decision. In the trademark infringement case, the registered trademark's distinctiveness should be decided at the time of an argument closing or commission of an infringement act. In light of the above legal principle, the subject case as an en banc case declared that in deciding whether a mark is similar to the registered trademark, the presence and intensity of the registered trademark's distinctiveness should be decided at the same criterion time of deciding the presence of similarity between marks. Its holding overruled precedents contrary to the above opinion. Further it held that where an element of the registered trademark acquire distinctiveness through separate use, and it is combined with other elements in the registered trademark, unless the combination makes already acquired distinctiveness of the element reduced or eliminated, the element can be the principal distinctive part of the registered trademark in deciding the presence of similarity between marks at trial to confirm scope of right. With the decision of the subject case, protection of a trademark was extended.