Recent Developments in Japanese Patent Law – Court Decisions from the Years 2018 and 2019

The Japanese Patent Act has been amended effective 1 April 2020 with respect to the calculation of the amount of damages and the involvement of neutral experts in production sites of an infringer. The amendments which are advantageous for a right owner are explained. Moreover there have been in the last two years again numerous decisions of the Intellectual Property High Court as well as of the district courts in Tokyo and Osaka with regard to patent law. These decisions relate to invalidation defenses in patent infringement law suits, the inventive step, the exhaustion of a patent right, the working of an exclusive license, the belated filing of an examination request, the calculation of damages in the case of patent infringement, the calculation of damages in the case of multiple patentees, the legal effect of a decision by the Japanese Patent Office in joint proceedings, the amendment of a patent application in appeal proceedings as well as the requirements for a divisional application.