Definiteness of Patent Claim : Claims are heart of the patent application. It is required that the specification of a patent conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor regards as the invention.
Definiteness of Patent Claim
The purpose of the definiteness requirement of claim language is to ensure that the public may be properly informed of the scope of the claims. Also, this requirement provides that any competitor who may want to work in the same domain shall be able to properly understand the boundaries of what constitutes infringement of the patent.
Further, the definiteness requirement of claim language provides a clear measure of what applicants regard as his/her invention. This may be particularly helpful to the Examiner during the prosecution and further to the Courts during claim construction stage, such as in a patent litigation case. The definiteness requirement further allows to determine whether the claimed invention meets all the criteria for patentability and whether the specification meets the criteria of 35 U.S.C. 112(a).
It is now generally accepted that definiteness is to be evaluated from the perspective of a person of ordinary skill in the art, as applies to the rest of the patent specification under 35 U.S.C. 112. Also, it has been generally accepted that for determining the definiteness requirement, the claims are read in light of the specification and prosecution history. Further, it has been widely accepted that the definiteness is measured at the time of filing of the application, and the ability to ascribe at least some meaning to a claim term does not meet the statutory test for precision at the time of the patent application.
It has been held by latest case laws and decisions of various Courts in US that a patent application is invalid for indefiniteness if its claims, read in light of the specification and the prosecution history, fail to inform those skilled in the art about the scope of the invention with reasonable certainty.