In In re Tanaka, 98 USPQ2d 1331 (Fed. Cir. 2011), Yasuhito Tanaka is the inventor of U.S. Patent No. 6,093,991 (the ‘991 patent), which relates to a one-way clutch which improves the efficiency of an alternator. Tanaka filed reissue application Serial No. 10/201,948 (“the ′948 application”) in which he attempted to broaden the claims. After having the broader claims rejected, Tanaka revised the claims to correspond to the original claim scope, and added a new dependent claim.
To support this new claim, Tanaka indicated in a substitute reissue declaration that he “did not fully appreciate the process of claiming according to U.S. practice,” “did not realize that I had claimed more or less than I was entitled to claim” and “the originally presented claims did not adequately define the invention because they were more specific than necessary.” The Examiner rejected the new claim since the Tanaka under 35 U.S.C. §251 since he did not identify an error on which reissue could be based since none of the claims were broader than the original claims, and since the new depending claim did not narrow the scope of the original claims.
The Board of Patent Appeals and Interferences did not find any controlling authority on this precise issue, and found that 35 U.S.C. §251 did not allow new depending narrowing claims as a source for error needed to allow a reissue application.
On appeal, the Federal Circuit found that the Board was incorrect in finding that there was no controlling authority, and therefore the decision was contrary to principles of stare decisis. Specifically, the Federal Circuit reviewed 35 U.S.C. §251, and noted that the statute allows correction where an error is made that “wholly or partly” renders the original patent invalid by claiming “more or less than he had a right to claim in the patent.”
Citing to In re Handel, 312 F.2d 943, 946 n. 2 (CCPA 1963), the Federal Circuit noted that the 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.’” In that case, Judge Rich had found that the reissue statute allowed an error where the inventor had claimed “less” by not including enough depending claims to hedge against potential invalidity of the independent claims. A similar decision was found in In re Muller, 417 F.2d 1387 (CCPA 1969), as well as in Hewlett–Packard Co. v. Bausch & Lomb, Inc., 882 F.2d 1556, 1564 (Fed.Cir.1989). While acknowledging that the issue has not been expressly stated by the Federal Circuit, this interpretation was assumed in these prior decisions. As such, the court formally adopted this interpretation of “less” as binding precedent for purposes of 35 U.S.C. §251.
The Federal Circuit similarly rejected the suggestion of the USPTO that the addition of new depending claims did not cure an error which rendered the original patent at least partially invalid as also required under 35 U.S.C. §251. Specifically, the Federal Circuit noted that new depending claims are themselves viewed as separate inventions having a distinct scope and purpose. Further, such depending claims can cure issues relating to claim interpretation under the doctrine of claim differentiation so as to clarify an independent claim that otherwise might be found invalid. The Federal Circuit also noted that such narrower claims have a purpose in hedging against potential invalidity. Thus, the addition of the new depending claim can correct an error in that the disclosed invention is not protected to the fullest extent allowed by law, which renders the original patent at least partially inoperative. As such, the Federal Circuit reversed the Board and found that the inclusion of a new depending claim can be the basis of a reissue application under 35 U.S.C. §251.
Significance for Patent Owners
Before Tanaka, where a patent owner believed the independent claims to be valid but wanted an insurance policy through new depending claims, the patent owner could only file these claims during a patent-owner-initiated ex parte reexamination. In this manner, the patent owner could include new claims, and defend the existing claims. However, the problem with this method is that the examination is confined within the limitations under the ex parte reexamination system, which does not allow for continuations and requests for continued examination as does regular examination. Tanaka indicates that patent owners now have the ability to add these new depending claims using the much more flexible reissue process, which does allow for continuations and requests for examination. Thus, where patent owners are looking to improve the odds in having the new claims thoroughly and properly examined, patent owners should elect to use the reissue process consistent with what was done in Tanaka.