In patent prosecution, an examiner often mentions the term "common knowledge" when evaluating a step forward in an invention, as one cannot patent common knowledge. Common knowledge in the IP sense is generally a fact known or ought to be known to one skilled in the art and can be applied by such a person to solve specific technical problems. Common knowledge can also be a technical means that is most likely to be considered and applied by one skilled in the relevant technical field when working on solutions to specific technical problems. As China’s Guidelines for Patent Examination (the "Guidelines") do not provide a clear definition for "common knowledge", the examiner and the applicant or the applicant’s attorney often disagree on what is common knowledge in a particular patent dispute.
Up to the present, no unified view has been formed regarding the scope of "common knowledge" among examiners, patent attorneys and academics in China. According to the Guidelines, common knowledge refers to technical means disclosed in publicly known textbooks or reference books, including technical dictionaries or manuals, and customary means in the art to solve a particular technical problem. It is generally accepted that technical dictionaries, technical manuals and textbooks can be used as evidences for ascertainment of common knowledge. But some believe that the scope of "common knowledge" provided by the Guidelines is too broad and that many technical dictionaries, technical manuals and textbooks should not be regarded as common knowledge although they are highly specialized.
Ascertainment of Common Knowledge
Regarding ascertainment of common knowledge, the majority view is that common knowledge should be "publicly known facts". It is also an established rule that publicly known facts (also known as "prominent facts") do not need to be proved. In general, publicly known facts refer to facts that are indisputable and known to all or most people in a certain region or specialized in a particular field. However, the following elements should be taken into account when one ascertains common knowledge as publicly known facts:
Firstly, publicly known facts do not necessarily be known to the general public but must be well known to those who are specialized in a certain field in a particular temporal and spatial scope. In other words, these facts are general technical common knowledge known to those skilled in the art prior to the filing date of the patent application.
Secondly, according to evidence law, publicly known facts may be introduced into evidence by judicial notice. A court can admit judicial notice of a publicly known fact in a given lawsuit case in any procedure or phase of litigation where it believes necessary or upon the concerned party’s request. Such notice is not subject to the time limit for submitting evidence.
Thirdly, where one party challenges the "common knowledge" asserted by the opponent party or confirmed by the Patent Reexamination Board, the opponent party or the Patent Reexamination Board should furnish pertinent materials and provide sufficient explanations. When one party raises opposition to a judicial notice taken by the court, the court should explain to the party the grounds on which and procedures via which the judicial notice is taken.
Fourthly, where there is counter evidence to overturn the facts confirmed through judicial notice, the party asserting the facts also needs to furnish evidence.
With regard to evidence, some think that common knowledge should be judged in accordance with knowledge of one skilled in relevant art and it is unrealistic to for the parties to adduce evidences for all common knowledge. Common sense in life does not need to be testified, nor does technical common knowledge. An exception is that the Patent Reexamination Board should bear the burden of proof when one party proves the confirmation of technical common knowledge by the Board is erroneous. Another view is that the coverage of common knowledge is wider than publicly known facts, which are not required to be testified, and the Patent Reexamination Board should only bear the burden of proof when a discrepancy exists between scopes of administrative notice and judicial notice regarding a particular fact.
Burden of Proof During Invalidation Procedures
a. A petitioner or the opponent party bears the burden of proof for its assertion that a certain technical means is common knowledge. If necessary, the Patent Reexamination Board can ask the party asserting certain technical means as common knowledge to adduce evidences.
b. Where one party explicitly raises opposition to the other party’s common knowledge assertion, the challenged party bears the burden of proof.
c. The Patent Reexamination Board may ex officio introduce common knowledge in its decision-making process. But the Board may increase its burden of proof in the proceedings by doing so.
During patent prosecution or invalidation proceedings, the examiner, the applicant and the attorney should define the scope common knowledge in the art involved in the patent applicant in question from the perspective of one skilled in the art. Examining and analyzing what facts or technical means should be subject to common knowledge helps to evaluate the inventive step of a patent application in a fair and reasonable manner and avoid abuse of common knowledge in the art.