특별행정심판인 특허무효심판에서의 무효사유 증명책임

In a patent invalidation trial, which is a special administrative trial, a requester and a requestee (patentee) contest one or more invalidation grounds. This paper discusses the person who may bear the burden to prove one or more invalidation grounds. For the purpose, this paper, firstly, clarifies the issue whether the applicant or the examiner may bear the burden of rejection-reasons proof in the patent prosecution procedure. A commentator differentiates rejection reasons into “right formation requirements” and “right obstacle requirements” and argues that the applicant must prove existence of the former requirements. This paper explains that such arguments are baseless: (1) textual interpretation of Articles 62, 63 and 66 of the Patent Act mandate the examiner to prove all rejection reasons; (2) because a patent decision as an administrative action is a confirmation action and non-discretionary action, if the examiner does not find any rejection reason, he must do patent decision; (3) patent prosecution practices do not differentiate right formation requirements and right obstacle requirements; (4) because an inventor is bestowed the right for a patent when he creates an invention, the examiner bears the burden to deny the right for a patent. In a patent invalidation trial, the “investigation” principle along with the “argument” principle is being applied. However, in the trial, under the normal administration law theory, it should be understood that the argument principle is basically applied and the investigation principle is, upon necessity, added. Especially, in a patent invalidation trial, the necessity for the requester to bear relevant burden is stronger under following reasons: (1) it is necessary to protect “trust interest” of the patentee who has trusted the administrative action of patent; (2) it is necessary to protect stability of other legal relationships made after the patent decision; (3) it is necessary to admit and respect expertise of the Patent Office; (4) a registered property is presumed to be legally registered; (5) to invalidate an administrative action, a relevant mistake must be serious and clear. It is the position of the Korea Supreme Court that the argument principle is firstly applied and, if necessary, the investigation principle is exploited in a trial-review litigation which is a subsequent stage following an invalidation trial. In addition, even though the plaintiff must assert illegality of a trial, a requester of the invalidation trial must still bear the burden to prove existence of an invalidation ground. Under the burden-of-proof jurisprudence in the above invalidation trial, the trial examiner does not decide whether the patent at issue is invalid or not. Because the requester of the invalidation trial bears the proof burden, the trial examiner does decide whether the requester fulfills his burden or not. In other words, the trial examiner may just decide that “because the requester has not fulfilled his burden to prove any invalidation ground, the patent can not be invalidated.”