특허침해소송에 있어서 선사용과 공연실시의 항변

Even a first inventor, i.e. an inventor who first devised an invention, infringes the patent right of another if he/she works the invention after the patent has been applied for. In contrast, if the first inventor was preparing to work the invention, or worked the invention, before the patent was applied for, the first inventor is entitled to a free nonexclusive license as an exception to the enforcement of the patent right. The prior use system, under which the free nonexclusive licenses are granted, is being used as one measure by which a first developer, who did not file a patent application, can be protected against an attack from a patentee. The first inventor can claim a prior use right if he/she was developing business in order to work his/her invention or has worked his/her invention. If the invention was in a state in which it could be publicly known while the first inventor was preparing to work the invention or was working the invention, it is more appropriate to argue for the invalidation of the patent right by asserting that the patented invention was publicly used rather than claiming the prior use right. This is because the argument based on the prior use right only grants a free nonexclusive license to one who infringes on a patent right, whereas the argument for the invalidation of the patent right allows completely unrestricted working of the invention in the future since the patent right can be invalidated. This research focused on the legal procedures that a person who has prepared to conduct business or who has conducted business in order to work an invention, acquired from a first inventor or another inventor, should take in order to prepare an argument based on prior use or public use. In addition, the evidences and facts that need be proved will be analyzed in light of precedents by comparing the two types of argument with each other. Based on such analysis and comparison, schemes for utilizing the prior use system and the public use system, which Korean companies can use in order to actively cope with patent disputes, will be proposed.