Addressing the issue of permissibility of adding a subject matter from its ancestor application back into the issued patent during its reexamination, the U.S. Court of Appeals for the Federal Circuit upheld the finding of the Board of Patent Appeals and Interferences (Board) that it is impermissible to do so without showing that the subject matter was inherently present in the continuation-in-part application for the patent. In re Reiffin Family Trust, Case No. 08-1544 (Fed. Cir., July 27, 2009) (Bryson, J.) (non-precedential).

In 1982, Martin G. Reiffin filed a patent application that disclosed an invention for providing compilation of a software program concurrently as the program is being entered or edited by the programmer. The application disclosed the compiler function of the system is interrupted in favor of the editor function, but not vice versa. The application also disclosed the compiler that performs “lexical, syntactic and semantic analyses of the source code” and informs the programmer if the sequence of symbols violates a syntactic or semantic rule.

In 1990 and 1994, Reiffin submitted two continuation applications that ultimately issued, respectively, U.S. Patent Nos. 5,694,603 and 5,694,604. The ’604 patent is directed to a “preemptive multithreading computer system with clock activated interrupt” and some of the claims are directed to the spell-checking and grammar-checking functions. Although syntactic and semantic analyses performed by the compiler are included in the 1982 application, Reiffin omitted the material in his 1994 application.

In 1998, Reiffin sued Microsoft Corporation alleging that the operating system and the spell-checking and grammar-checking features of Microsoft’s Word program infringed his ’604 patent. The district court ruled that the ’603 patent was invalid for failing to comply with the written description requirement and that the ’604 patent was not entitled to claim priority to a filing date of 1990 or earlier. Reiffin then voluntarily requested re-examination of the ’604 patent, arguing that he had disclosed “multithreading” in his 1982 application and that the ‘604 patent is entitled to a 1982 priority date. The examiner found that the 1982 application did not describe multithreading and the Board agreed with the examiner in finding that “multithreading” requires all threads to be interruptible, but the 1982 application did not disclose the editor to be interruptible. The Board found that the ’604 patent was entitled to 1994 priority date and held most of the claims invalid as anticipated or obvious by a 1988 prior art.

The Board also rejected the ’604 patent claims directed to the spell-checking and grammar-checking functions for lack of written description. Although a continuous chain of copending applications allows the applicant to add matters from an earlier application to be added through amendment to a continuation-in-part application, the Board found that Reiffin’s decision to omit the relevant material in his 1994 application created a break in the chain of disclosures when he let the ’604 patent issue without amending its application; the break cannot be cured by an amendment during reexamination of the patent.

In affirming the Board’s findings, the Court reasoned that although a patentee is permitted to amend both the claims and the specification of his patent on reexamination, he is not allowed to do so in a manner that has the effect of enlarging the scope of the patent’s claims. The Court acknowledged that Reiffin did not directly seek to broaden the scope of claims in question, but the amendment he sought would have had the same effect and broadened the scope of the invention and expanded the universe of potentially infringing products. The Court went on to apply the rule of Dart Industries, Inc. v. Banner, which had a similar facts involving reissue application instead of reexamination. The Dart court also concluded that continuity was lost when the continuation-in-part application was filed without the material from its prior application. When the patent issued from the continuation application, the applicant’s “failure to maintain a continuity of disclosure of [the feature in question] became uncorrectable.”

Practice Note: This case highlights the importance of maintaining the continuity of disclosure when filing subsequent copending patent applications. A thorough analysis of prior applications’ disclosure to ascertain continuity is vital as it will no longer be correctable once the patent issues