[Title of the patent] “(Meth)acrylic acid ester copolymer”

[Key issue] Inventive step (Article 29, paragraph (2) of the Patent Act)

Court rescinded a JPO’s revocation decision, stating that the patent invention could have been easily conceived of by a person skilled in the art based on Cited Invention 1, since there was little motivation to improve Cited Invention 1 to solve the problem of the patent invention because the technical field and the problem are not necessarily the same for the patent invention and Cited Invention 1 and according to the disclosure of Citation 1 (Exhibit Ko 7), there is little reason for a person skilled in the art to select the two kinds of monomers, a monomer containing epoxy groups and a monomer containing hydroxy groups, from among multiple combinations disclosed in Citation 1.