TIPS^®  Taiwan Intellectual Property Special

Admissibility of Affidavit Evidence in the Patent Disputes

The legal systems in the world can be divided into common law and civil law jurisdictions. Common law jurisdictions were developed in England and tend to be found in her former colonies and territories, such as the U.S., Canada, Australia, New Zealand, Hong Kong, Singapore, Malaysia, and India. Civil law has developed from Roman Law, and is utilized in many western European countries, as well as in Japan, Korea and Taiwan. For inter partes dispute resolution, in general, there is no discovery procedure available for the parties in the civil law countries. The differences between the systems can affect the outcome of patent opposition, invalidation, and litigation. For example, whether an affidavit is admissible as evidence may be determinative in a patent trial.

One of the fundamental principles of Taiwan civil proceedings is that the courts only deal with those facts put forward by the parties. However, in an administrative proceeding, the administrative body or the court should conduct an ex offiicio investigation of the facts, an evaluation of the evidences presented by the parties. An affidavit is an ex parte written statement made under oath before a notary public and is often used along with evidences to prove prior sale or prior arts to invalidate a patent. Notwithstanding, it is a private document whose creditability has long been questioned in Taiwan under the legal principles of civil laws.

According to the Guidelines of the Patent Examination, a private document is one form of evidences. Although the parties in an inter partes procedure always raise arguments against admission of private documents, a private document is admissible as evidence as long as it is authentic and relevant to the disputes. In other words, if an affidavit is authentic and relevant for proving the disputed facts, it may be admissible as evidence. Therefore, the creditability of an affidavit should not be denied simply because it is a private document. Particularly, if it is proved to be a clear and convincing evidence by linking undisputed documents.

Nevertheless, the Guidelines of the Patent Examination are not the binding law, but a reference for examining the patent prosecution and invalidation. Whether the Committee of Administrative Appeals or the judges at the Administrative Courts or regular courts will follow the Guidelines is totally upon their discretion, and, sometimes, the discretion has a decisive influence on the outcome of the case.