Emergence of Essential Patents in Technical Standards: Implications of the Continuation and Divisional Application Systems and the Written Description Requirement

The present paper looks into the intersection between technical standard development activities and patenting activities from the perspective of patent prosecution. Specifically, attention is paid to the tendency that the obtainment of patents related to technical standards is often done through the utilization of the systems allowing patent applicants to file new applications (collectively called continuing applications under the US patent system) enjoying the benefit of the filing dates of earlier-filed patent applications. After presenting some empirical evidence to show the tendency (in other words, the relevance of the continuing application system to patenting technical standards), this paper focuses upon the written description requirement as an important factor affecting the patentability of such continuing applications. In this paper, I make concrete proposals for the enhancement of the capacity of the written description requirement to suppress the abusive use of the continuing application system to cover technical standards as well as competitors' products and processes, without prejudice to innovative inventors' opportunities to mine their original disclosure in patent specifications for the exclusive rights they deserve. These proposals of mine include the reduction of burden of proof, to the patent challenger's side, of incompliance of a claim in a continuing application with the written description requirement, when certain conditions are met, and some examples of ways to achieve such reduction of burden of proof. This paper also presents comparative review of the continuing application systems under the European and Japanese patent systems as well as the US patent system. Based upon the review, relevant international harmonization considerations are discussed as well.