Narrow Disclosure Limits Claim Scope

American Calcar v. American Honda (decided 6/27/11

By: Gerald B. Hrycyszyn

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What This Means to You

  • When drafting patent applications, be aware that a narrow disclosure can limit claim terms that are otherwise broad on their face.
  • Similarly, when defending against allegations of infringement, look for narrow disclosures that might limit the claim scope.
  • Do not define the “invention" narrowly; provide a broad disclosure with numerous examples where possible.
  • The doctrine of claim differentiation is not conclusive – a narrow specification will override its effect.

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Overview

In American Calcar, Inc. v. American Honda Motor Co., the US Court of Appeals for the Federal Circuit (Federal Circuit) relied on a patent’s narrow disclosure and descriptions of the “invention” to limit the scope of claim terms.

The Federal Circuit also applied its new standard for proving inequitable conduct as set forth in its Therasense case (click here for our analysis of this case). The district court analyzed the allegations under pre-Therasense law and, therefore, did not make the necessary findings to support inequitable conduct under the new requirements. The Federal Circuit remanded the issue.

Case Background

American Calcar Inc (ACI) sued Honda alleging infringement of nine patents directed to various aspects of car computer systems.

The inventors all worked for ACI’s predecessor, Calcar, which developed car manuals. Honda was a Calcar customer. The inventors drove Honda’s Acura 96RL and obtained a copy of the user manual for its navigation system. Shortly after their test ride, the inventors hired a patent attorney and started working on the patent applications at issue. During litigation, an inventor admitted that Honda’s Acura 96RL navigation system was the basis for their invention. The PTO was not provided with details—such as the user manual—on the Acura 96RL navigation system, which was only generally noted in the background of the patents.

The district court found three of the nine patents unenforceable due to inequitable conduct. Only one of the nine asserted patents was found valid and infringed.

Decision Analysis

The Federal Circuit relied on narrow disclosures and descriptions of the invention to limit the scope of claim terms. For example, the Federal Circuit found that the term “messages” must include an address in the format “<vehicle-id>@<domain>” because, inter alia, the specification states “in accordance with the invention, a C-mail address is in the format of <vehicle-id>@<domain>.” (“C-mail” designates a specific car instead of a person.)

The fact that a dependent claim added such a specific limitation to “messages” did not sway the court. It held that the doctrine of claim differentiation is not conclusive; a narrow specification will override the effect of the doctrine. The court used similar logic to limit the scope of several other terms.

The Federal Circuit also held that the facts noted above and a district court finding that the inventors were not credible, were not enough to support an inference of intent to deceive. It remanded the intent to deceive issue for further proceedings.

Takeaways

In drafting specifications, strive to write broad descriptions with numerous examples, where feasible. Applicants should avoid limiting the description of the invention to specific embodiments in the specification, because the claims might be limited to those embodiments even if the claim language seems broader.

Applicants should also remember that the doctrine of claim differentiation has its limits. It is not a conclusive basis for construing claims, and a specification can override its benefit.