Applicants commonly provoke an interference by copying into their application (the "host application”) a claim from someone else’s pending application or issued patent. As the interference progresses, the other party may challenge the applicant’s right to do this by contending that the copied claim lacks written description in the host application under 35 USC § 112, or that the claim is unpatentable to the applicant as anticipated or obvious under 35 USC §§ 102 or 103 by virtue of the prior art.

In Koninklijke Philips Electronics NV v Cardiac Science Operating Co (590 F3d 1326 (Fed Cir 2010)) the Federal Circuit explained that the specification used to construe a copied claim depends on the purpose of the construction. Specifically, the copied claim is:

  • Construed based on the originating application when the question is whether the claim has written description support in the host application (the Spina rule, after In re Spina, 975 F2d 854 (Fed Cir 1992)).
  • Construed for the purposes of determining patentability over the prior art based on the host application (as would be the case in prosecution).

Although the court has stated these rules of construction before, their illustration here is notable because both constructions were required in the same case. This is because the copied claims were attacked both on written description grounds and on prior art grounds, requiring the use of different constructions to resolve the separate grounds of attack.

Owen, the applicant, provoked an interference by copying claims from a patent issued to Koninklijke Philips Electronics NV. The Board of Patent Appeals and Interferences formulated one count for the interference, corresponding to one of the claims that Owen copied from Philips.

Philips contended that Owen could not make the count because Owen’s specification did not provide written description support when the claim used to formulate the count was construed in view of the Philips specification. Philips also argued that if the claims were construed based on Owen’s specification, they were unpatentable over the prior art.

The board rejected Philips’ written description challenge, stating that the Philips patent was irrelevant to construction of a claim that would (if allowed) be in a patent to Owen. In doing so, it relied on 37 CFR 41.200(b), which requires claims in an interference to be given their broadest reasonable construction based on the specification in which they appear (without regard to the grounds of challenge). (The board’s decision is available at https://acts.uspto.gov/ifiling/PublicView.jsp under Interference 105,451.)

According to the board, the US Patent and Trademark Office (USPTO) had authority to promulgate Section 41.200(b) in 2004, effectively overruling the Spina rule (dating from 1992), because of the Federal Circuit’s intervening decision in Rowe v Dror (112 F3d 473 (Fed Cir 1997)), which endorsed construction of a copied claim based on the host application. Unlike in Spina, however, the copied claim in Rowe was challenged on prior art grounds (Rowe, 112 F3d at 479). Although the court observed in Rowe that its holding was consistent with the USPTO’s then existing Interference Rule 633(a), the predecessor of Section 41.200(b), it noted that the USPTO had no authority to overrule precedent by rulemaking and rejected the USPTO’s statement that it had administratively set aside Spina by promulgating Rule 633(a) (112 F3d at 479 n 2).

In Philips the Federal Circuit rejected the board’s reliance on Section 41.200(b) and explained that Rowe was inapplicable because it involved a challenge to a copied claim based on prior art. The court noted that despite the distinction between Rowe and Spina, “some parties still misunderstand when the Spina rule should apply” (590 F3d at 1335). It further held that the board had (again) erred in believing that the USPTO could effectively negate Spina by rulemaking, reminding the USPTO that the agency lacks substantive rulemaking authority and must resolve conflicts between controlling precedent and its rules in favour of the precedent (id at 1337).

To patent lawyers raised on the doctrine that claims must be construed consistently for purposes of infringement and validity, a doctrine requiring different constructions of the same claim may seem anomalous. Perhaps this seeming inconsistency also troubled the board and influenced its decision to disregard the Spina rule and construe the copied claim based on the host application (as the claim would be construed in ex parte prosecution and in an interference to determine its patentability over the prior art). However, the Spina requirement to construe a copied claim for written description purposes based on the originating application makes sense because the fundamental issue in an interference is which party has the right to the claimed invention. If a copied claim is not supported by the application into which it is copied, that application does not belong in an interference with the application or patent from which the claim was copied. Because the copied claim must have the same meaning to both parties when this threshold issue is addressed, it is construed based on the originating application or patent.

If this threshold is crossed, the inquiry becomes whether the copied claim is patentable in the host application over the prior art. For that purpose, the claim must be construed based on the host application (as in ordinary prosecution), because if the copied claim issues in a patent from the host application, it will be construed based on that application.