In In re Tanaka, the Federal Circuit held that the reissue process can be used to make the sole change of adding dependent claims to a granted patent. The ability to file a reissue application to add dependent claims to hedge against the risk that originally granted claims will be held invalid could salvage a patent from being inoperative or invalid under evolving legal standards, such as more stringent written description, enablement or patent eligibility requirements.
The statute at issue is 35 USC § 251:
Whenever any patent is, through error without any deceptive intention, deemed wholly or partly inoperative or invalid, by reason of a defective specification or drawing, or by reason of the patentee claiming more or less than he had a right to claim in the patent, the Director shall, on the surrender of such patent and the payment of the fee required by law, reissue the patent for the invention disclosed in the original patent, and in accordance with a new and amended application, for the unexpired part of the term of the original patent. No new matter shall be introduced into the application for reissue.
37 CFR § 1.175 prescribes requirements for the reissue oath or declaration:
(a) The reissue oath or declaration in addition to complying with the requirements of § 1.63, must also state that: (1) The applicant believes the original patent to be wholly or partly inoperative or invalid by reason of a defective specification or drawing, or by reason of the patentee claiming more or less than the patentee had the right to claim in the patent, stating at least one error being relied upon as the basis for reissue; and (2) All errors being corrected in the reissue application up to the time of filing of the oath or declaration under this paragraph arose without any deceptive intention on the part of the applicant.
Further, if any other "errors" are corrected during prosecution of the reissue application, the applicant must submit a supplemental oath or declaration pertaining to those errors.
Tanaka originally filed a reissue application in order to broaden the scope of independent claim 1 of his patent. During prosecution, however, Tanaka dropped this strategy and pursued the originally granted claims and a new dependent claim.
Tanaka submitted a supplemental reissue declaration stating that "because I did not fully appreciate the process of claiming according to U.S. practice, I did not realize that I had claimed more or less than I was entitled to claim" and that "the originally presented claims did not adequately define the invention because they were more specific than necessary."
The Examiner rejected the claims, based on non-compliance with the reissue statute:
[T]he error specified in the oath . . . is not an error correctible by a reissue. The Applicant has not specified an error that broadens or narrows the scope of the claims of [the] issued patent . . . . The original claim 1 remains in the current reissue application, therefore the broadest scope of the patent remains the same.
The Board of Patent Appeals and Interferences (an expanded panel of seven judges) issued a precedential opinion affirming the rejection. The Board framed the issue as whether
the presentation of a narrower claim in a reissue application that still contains all of the original patent claims . . . present[s] the type of error correctible by reissue under 35 USC § 251.
The Board did not identify any controlling precedent, but held that the statute does not permit "reissue applications that simply add narrow claims . . . when no assertion of inoperativeness or invalidity for the reasons set forth in § 251 can be made by the patentee." In affirming the rejection, the Board noted that "Tanaka was impermissibly seeking an additional claim on reissue 'in order to hedge against the possible invalidity of one or more of the original claims.'"
The Federal Circuit reviewed the issue de novo, and found that "the Board’s determination is contrary to longstanding precedent of this court and flies counter to principles of stare decisis."
The court cited a "half century" old case, In re Handel, 312 F.2d 943 (CCPA 1963), that it found to be directly on point:
Nearly a half century ago, our predecessor court, the Court of Customs and Patent Appeals, clearly stated that adding dependent claims as a hedge against possible invalidity of original claims "is a proper reason for asking that a reissue be granted."
The court acknowledged that the discussion in Handel might be dicta, but noted other cases that likewise permitted reissue applications that added dependent claims without altering the scope of the originally granted claims. Thus, the court determined:
Even though the rule that adding a dependent claim as a hedge against possible invalidity is a proper reason to seek reissue has seemingly never been formally embodied in a holding of this court or its predecessor, articulation of the rule in Handel was not simply a passing observation—it was a considered explanation of the scope of the reissue authority of the PTO in the context of a detailed explanation of the reissue statute. Based on this court’s adoption of that rule and its adherence to the rule in both Muller and Hewlett-Packard, this court rejects the Board’s contrary ruling.
(Is the court saying that "half century old dicta," like Supreme Court dicta, holds a certain cachet?)
Addressing the reissue requirement that the original patent be "wholly or partly inoperative or invalid," the court discussed the independent rights associated with each claim of a patent, and explained that "the omission of a narrower claim from a patent can render a patent partly inoperative by failing to protect the disclosed invention to the full extent allowed by law."
Thus, the court directly and expressly followed the "rule" set forth in Handel:
"[T]he narrow rule relating to the addition of dependent claims as a hedge against possible invalidity has been embraced as a reasonable interpretation of the reissue statute by this court and its predecessor for nearly fifty years without any obvious adverse consequences. To deviate from that long-standing interpretation would be contrary to the doctrine of stare decisis and is unwarranted."
Judge Dyk dissented from the majority decision which was authored by Judge Linn and joined by Judge Bryson.
Judge Dyk agreed with the Board that no prior decisions "squarely addressed or decided whether seeking to include narrower claims while retaining the original claims is a proper basis for reissue under § 251."
According to Judge Dyk:
By retaining the original claims without alteration or amendment, the applicants have admitted that there was no error in the original patent. The fact that no error is being corrected here . . . makes reissue unavailable in this case.
The Federal Circuit decision here underscores the importance of reissue as an option for addressing "defects" that are discovered after a patent is granted. This option may be increasingly important in the context of biotech and pharmaceutical patents, where the legal requirements for written description, enablement and even patent-eligibility are in flux. The ability to file a reissue application to add dependent claims to hedge against the risk that originally granted claims will be held invalid under a more stringent written description requirement or under a new patent-eligibility requirement could salvage a patent from being inoperative or invalid under evolving legal standards.