When filing a patent, a patent application must include one or more claims which particularly point out and distinctly claim the subject matter which the applicant regards as his or her invention. Patent claims serve two functions. First, they define the invention for the purpose of applying the conditions of patentability, the statutory bars, and the disclosure requirements. Second, they define the invention for the purpose of determining infringement.
Claims must be particular and distinct. The primary purpose of this requirement of definiteness in claims is to provide clear warning to others as to what constitutes infringement of the patent. Another purpose is to provide a clear measure of the invention in order to facilitate determinations of patentability.
On occasion courts have failed to distinguish the definiteness requirement, which claims must meet, from the enablement requirement, which the specification disclosures must meet. However, the two requirements are distinct. A patent specification may sufficiently teach how to make and use the invention yet fail to claim it with sufficient particularity.
The definiteness standard is one of reasonableness under the circumstances. It is whether, in the light of the teachings of the prior art and of the particular invention, the claims set out and circumscribe a particular area with a reasonable degree of precision and particularity. A clear claim can be rejected as for something other than what the applicant ”regards” as his or her invention only if some material submitted by the applicant, other than the applicant’s specification, shows that the claim does not correspond in scope with what the applicant regards as the invention.