Chapter §21.06 Reexamination Compared to Reissue

• Jurisdiction: United States

§21.06 Reexamination Compared to Reissue

The reexamination and reissue procedures differ in fundamental respects. Reexamination is narrower than reissue in the sense that reexamination cannot be used to correct defects other than anticipation and obviousness based exclusively on the content of the prior art references.²⁹⁷ Reexamination is broader than reissue, however, in the sense that anyone can request reexamination,²⁹⁸ while only the owner of the patent in question can seek to reissue it.²⁹⁹

The most important difference between the two procedures is likely the fact that, unlike reissue, reexamination cannot be used to broaden the claims of an issued patent.³⁰⁰ There is no broadening reexamination. For example, in Quantum Corp. v. Rodime, PLC,³⁰¹ the accused infringer brought a declaratory judgment action seeking a declaration that a previously reexamined patent, directed to a micro hard-disk drive system suitable for use in personal computers, was invalid and not infringed. The validity challenge was based on the facts that as originally issued, the claims of the patent recited a track density of "at least 600 concentric tracks per inch," but that during reexamination, the patentee amended the claims to recite "at least approximately 600 concentric tracks per inch," and the USPTO issued a reexamination certificate confirming the patentability of these amended claims. The accused infringer thus contended that the amendments made by the patentee during the...