Critical study on patent infringements and presumption of negligence


Presumption of negligence in finding liability of patent infringements was introduced in the Korea Patent Act of 1974 by imitating the Japanese Patent Act amendment of 1959. Interestingly, the Japanese amendment was motivated by the UK Patent Act of 1949 which exempted the monetary liability of an innocent infringer. This was a misunderstanding of the purpose of the UK Patent Act and the law of liability for wrongdoing. Throughout comparative legal analysis of treaties and national laws, it is hard to find similar examples that provide both the principle of negligence liability and the statutory exception of the principle by switching a burden of proof.

Fifty years after the introduction of the presumption of negligence, the rule now becomes an assumption rule. The court, regardless of the type of infringing activities, does not recognize the reversal of presumption of negligence, and takes the attitude that the negligence is naturally assumed not only for direct infringement but also for indirect or equivalent infringement. An alleged infringer is unable to escape from the presumed liability even when it trusts the court’s judgment on the validity or scope of patent rights. The predictability and avoidability of patent infringement, contrary to the idea and expectation of legislators, require highly expensive efforts, putting an excessive burden upon technology users. Now, it is time to seek balanced institutional changes that impose cautionary duties on patent holders to prevent an accidental infringement as well, and to reform courts’ practices.

This article published in Industrial Property Rights Vol. 66, Korea Intellectual Property Society, January 2021, is downloadable (Full text is in Korean)