Interpretation Of Means-plus-function: Practice And Reference Of The United States

Judge Giles of US Federal Court takes patent system as “A Game of Claim”,from which the importance of claim in patent system is becoming obvious. However,the claim is presented via language, which may cause ambiguity of the subject mattertrying to be protected by patent system, as language is two-dimension while theclaimed invention is multi-dimension. Thus, the interpretation of a claim, whichactually is the interpretation of elements that constitute the claim, is pretty important.Furthermore, one element is able to be expressed in the form of “what the element is”or “what the element does”, wherein element expressed in the later form is calledmeans-plus-function.According to the regulation of “Guidelines for Patent Examination”,means-plus-function is not recommended in China. Even so, claims withmeans-plus-functions are very common especially patent applications from UnitedStates because of the influence of United States and the development of signalprocessing, computer and communication technology, where means-plus-functions arefrequently used.However, regulations in China for governing functional claim are imperfect. Onone hand, interpretations of the scope covered by means-plus-function between patentgranting procedure and infringement determination process are different from eachother, which result in uncertainty of the patent right scope and bring confusion to thepatent owner and the public. On the other hand, application of regulations that relatedto means-plus-function is defective.Correspondingly, in United States debates on functional claim could date back to the year of1840, and particular law about it was provided in the year of1952, thatwas,35U.S.C112§6. Through more than60years development, regulations onmeans-plus-function had been gradually improved. Thus, from analysis of the UnitedStates’ approach, comprehensive understanding of means-plus-function is able to beobtained. Based on this, through further discuss of the development history ofmeans-plus-function in United States, basis of and reasons for35U.S.C112§6willbe illustrated.This article comprises three parts, the first part introduced problems related to thesubject under research and intended to be solved via a plurality of judicial cases inChina. The second part is the main part of this article, which centered around UnitedStates’ approach on Means-plus-Function. Wherein, first section of this part detailedthe35U.S.C112§6,thus clarified what kind of functional limitation was applicable tothis regulation, and illustrated how to put this regulation into practice. Second sectionof this part illustrated the reasons and basis of35U.S.C112§6via analysis of itsformation history. The third part is the core of this article, wherein research methodsmainly including theoretical analysis and historical analysis had been used. On onehand, the development of claim as part of the specification to define the protectionscope under patent system, and different roles of claim and description are illustrated,from which the conclusion that disclosure given by description can be used tointerpret claim but it can’t be imported into the claim as a limitation is obtained. Onthe other hand, from analysis of the formation history35U.S.C112§6, it can be seenthat the interpretation of means-plus-function regulated by35U.S.C112§6is basedon judicial strategies and intuition of functional claim that taking claims limited byfunctional language as too broad, thus it can be concluded that strict interpretation ofmeans-plus-function claim does not have good reasons and solid basis. Then practicalproposes suitable for China’s current situation were given so as to improvement thepatent system in China.This article not only illustrated approaches towards means-plus-function inUnited States, but also analyzed the development history of it, which is the innovationpoint of this research.