Today, there is growing interest in standard-essential patents belonging to patent pools, a distinctive form of standardization consortium, in the fields of business strategy and technology innovation strategy. Existing research has had an insufficient understanding of what knowledge bases these standard-essential patents were created from and what performance outcomes resulted accordingly. This paper examines which types of knowledge search lead to higher innovation performance among standard-essential patents belonging to patent pools. For this purpose, 662 standard-essential patents belonging to competing DVD patent pools (DVD3C and DVD6C) were studied. In this paper, knowledge search types were classified by simultaneously considering the new network boundary of the patent pool—a multi-party strategic alliance—in addition to the conventional organizational boundary, and their relationships with innovation performance were analyzed. The empirical results of this study showed that knowledge search within the same organization and within the patent pool, as well as knowledge search from other organizations within a competing patent pool, had positive effects on performance. In contrast, searching the knowledge of other organizations within the same patent pool had a negative effect on innovation. This study identified knowledge importance as a new knowledge characteristic through which the exploitation of internal organizational knowledge positively affects performance. Furthermore, it suggests that knowledge search from organizations in a coopetition relationship within the same patent pool is detrimental to innovation, whereas knowledge search from organizations in a competitive relationship within a rival patent pool is beneficial to innovation.