If a patent owner has disclosed, but not claimed some embodiments of the invention, resort to the doctrine of equivalence to protect such unclaimed embodiments may be lost through the doctrine of prosecution history estoppel. Let’s assume, for sake of argument, that the patent application that led to the patent contained no claims to the genus covering the species set forth as separate embodiments of the invention and the prosecution history of the patent contained no arguments applicable to the unclaimed embodiments. Consequently, if the patent is less than two years old, the patent owner may seek to correct this error in claiming less than she was entitled to claim through the filing of a broadened reissue application claiming the previously unclaimed embodiments of the invention. The doctrine of impermissible recapture in such circumstances would not apply. In accordance with MPEP § 1412.01: Claims presented in a reissue application are considered to satisfy the requirement of 35 U.S.C. 251 that the claims be “for the invention disclosed in the original patent” where: (A) the claims presented in the reissue application are described in the original patent specification and enabled by the original patent specification such that 35 U.S.C. 112 first paragraph is satisfied; and (B) nothing in the original patent specification indicates an intent not to claim the subject matter of the claims presented in the reissue application. The presence of some disclosure (description and enablement) in the original patent should evidence that applicant intended to claim or that applicant considered the material now claimed to be his or her invention. **** **>One should understand<, however, >that< the mere failure to claim a disclosed embodiment in the original patent (absent an explicit statement in the original patent specification of unsuitability of the embodiment) would not be grounds for prohibiting a claim to that embodiment in the reissue. Filing a reissue application to claim previously unclaimed embodiments of the invention must be filed within two years of the issuance of the original patent, if claims to the previously unclaimed embodiments would read on something which the original claims do not. This would presume that no claims to the genus covering all the embodiments of the invention existed in the original patent. The test for a broadening reissue is whether the reissue patent claims would be infringed without infringing the original patent claims. This gambit will avoid the loss of potentially valuable patent rights where the patent owner did not file a voluntary divisional application to seek protection for the previously unclaimed embodiments of the invention before issuance of the original patent.
