The Evolution of English Patent Claims as Property Definers

Abstract:     
A claim is a concise unilateral written expression of patent scope made by the patentee at the time of application. Claims are contained within a patent specification in which the patent applicant also provides a full written disclosure of the new invention. The invention publicly disclosed should provide a basis to support any claim made. This essay outlines how it was that patent claims in English law came to define the subject-matter scope of any particular patent. The essay traces this evolution from the time of the 1623 Statute of Monopolies to Lord Hoffmann's 2004 decision in Kirin-Amgen v Hoechst Marion Roussel. Claims emerge in patent custom as a response to the judicial development of patent law. Of particular importance were the recognition of incremental invention and the obligation that the patent fully discloses the invention, which together were the catalyst for the emergence of the English patent claim. Viewed within their timeline, two key insights about claims emerge. The first is that the precise ascertainment of patent scope has been something required of claims more in theory than in practice. While the trends have varied, the dominant English tendency has been for courts to determine patent scope ex post, and to not too strictly require that claims delineate scope ex ante. The other insight from the essay is that claims have only been unambiguously accepted as the source of patent scope in relatively recent times, and the recency of this acceptance may suggest a more critical eye should be cast over claim construction methodologies.

Number of Pages in PDF File: 39

Keywords: Article 69, Patent, European, property, define, English, law, claim

JEL Classification: K11

Accepted Paper Series