Patents
In the context of the proceedings at the European Patent Office, third parties may dispute the validity of a granted European patent by filing a post-grant opposition under the European Patent Convention (EPC).
In Germany, third parties may dispute the validity of a pending German patent application under German patent law.
Under United States patent law, an opposition proceeding is called a reexamination. Post-grant review provisions of the new patent law may affect a potential patent infringement defendant’s strategies in filing a declaratory judgment action. Under the new Leahy-Smith America Invents Act, any third party can challenge the validity of an issued patent using either post-grant review under 35 U.S.C. § 321 or inter partes review under 35 U.S.C. § 311. Both proceedings are effective September 16, 2012.
In Japanese patent law, opposition procedure after an examiner's decision to grant a patent was abandoned in 2003; trial for invalidation serves as the alternative.
Read more about this topic: Opposition Proceeding