Soothing headaches surrounding the issue of common knowledge

In patent examination practice in China, particularly when the issue of the inventiveness of a patent is involved, there is disagreement between examiners and applicants as to whether certain distinguishing technical features (or combinations of features) are “common knowledge”, causing great headaches for applicants.

Regarding common knowledge, examiners will often use “commonly used technical means”, “conventional choice” and “conventional design”, which essentially mean the same thing. However, there is no definition of common knowledge to be found in the Patent Law or its Implementing Rules, with only the following few instances provided in the Patent Examination Guidelines.

In a substantive examination. Part 2, substantive examination, of the guidelines specifies that an examiner can determine the inventiveness of a claim by bringing in “common knowledge” and taking into account the reference documents. Furthermore, chapter 8 of part 2 of the guidelines specifies that the common knowledge of the art in the office action by the examiner should be accurate. When the applicant objects to the common knowledge cited by the examiner, the examiner should be able to explain their reasons or provide supportive pertinent evidence.