Nagata Kentaro, Kuboyama Tetsuji
IPSJ SIG Notes, 2009(11) 31-38, Feb 6, 2009
A patent is an intellectual property which possesses legal uncertainty and it has the risk of patent invalidity at the stage of exercising the rights, e.g. license negotiation, demand for injunction, etc. In this study, we tried to search the factors which increase or decrease the risk, namely, the factors correlated to the validity of a patent. To be concrete, our analysis starts from selecting patents held valid or invalid by the Tokyo High Court (presently the IP High Court), terminated during the period of 2000-2006, and we set up an assumption if a patent is held valid in the court, the patent possesses high validity (difficult to be held invalid). Then, by using the method of machine learning for feature selection, we conducted a survey of the factors based on filing documents and the prosecution history. As a result, we found there existed several effective factors correlated to the validity of a patent in court level.