Plain and Ordinary Meaning Tempered by Application Examples

Posted by Matthew Grady on Jun 20, 2016

In Eon Corp. v. Silver Spring Networks, the Federal Circuit reversed a finding of infringement, identified a failure to construe “portable” and “mobile,” and directed entry of a judgment of non-infringement based on a proper construction of the plain and ordinary meaning of mobile and portable.

What This Means to You

  • Interpretation of plain and ordinary meaning of claim terms is conducted in view of the specification.
  • Ambiguous examples may not support broader claim scope, especially where detailed examples provide support for a narrower interpretation of the claims.
  • Explicitly claim all your embodiments and, if possible, keep continuation applications pending to provide an opportunity to resolve ambiguity.

Case Background

Eon Corp. sued Silver Spring Networks on three patents covering networks for two-way interactive communication. The accused devices were power meters typically installed outside a residential home. At the district court, the jury found infringement and awarded damages of $18.8 million. Silver Spring requested judgment as a matter of law notwithstanding the jury verdict. The district court found one of the three patents not infringed as a matter of law (for reasons unrelated to construction of portable and mobile) and remitted damages to approximately $13 million.

Decision Analysis

On appeal, a panel majority of the Federal Circuit held that no reasonable jury could have found infringement under the proper construction of portable and mobile recited in the claims. Silver Spring’s challenge regarding those words  was two-fold. First, it argued that the district court’s decision not to construe the claims improperly delegated claim construction to the jury. Second, it contended that no reasonable jury could have found infringement based on a proper construction of portable and mobile. The Federal Circuit agreed with Silver Spring on both grounds. 

Referring to O2Micro, the court instructed that “a determination that a claim term ‘needs no construction’ or has ‘plain and ordinary meaning’ may be inadequate when reliance on a term’s ‘ordinary’ meaning does not resolve parties’ dispute.” Silver Spring argued that the claim terms do not cover “fixed or stationary products that are only theoretically capable of being moved.” The Federal Circuit instructed that, by determining only that the terms should be given plain and ordinary meaning, the district court improperly left this question unanswered.

Having determined the district court erred, the Federal Circuit turned to the meaning of portable and mobile in the context of the examples and description recited in the patent. Quoting Phillips v. AWH Corp.,  it stated that the proper construction is not “the meaning in the abstract … but the meaning to the ordinary artisan after reading the entire patent.” The majority found that the patents-in-suit consistently differentiated portable and mobile units from other fixed and stationary units. Further, the patents describe that during movement the units maintain “good synchronous digital communication.” This context precluded reading the claims on Silver Spring’s fixed position power meters. The meters in question are typically installed at a residence and left in place for 10 or more years. Of note, the parties agreed that portable and mobile would have the same meaning and could be construed the same, and foreclosed any argument for a different construction of either term.

In the dissent, Judge Bryson disagreed that the claim construction should be so limited. The dissent noted that examples in the specification contemplate fixed-position devices. However, as the majority explained, the examples are not specific and need not be interpreted as fixed-position devices, but rather could be portable devices for capturing information from fixed-position devices. 


  • Avoid reliance on plain and ordinary meaning wherever possible. Ensure that embodiments you wish to protect are explicitly recited and in your claims.
  • Preserve your arguments whenever possible. Conceding that portable and mobile could be construed with the same meaning may have cost the patentee.
  • When changing terms between related applications, think through the possible meanings of your new selection of terms and the impact those meanings may have on terms in your related cases. Plan your use of terms carefully.

Wolf Greenfield's CAFC Blog

Here, Wolf Greenfield attorneys summarize and identify key takeaways from recent patent law cases decided by the U.S. Court of Appeals for the Federal Circuit. View past case summaries here.

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This blog is intended to promote thought and debate on developing areas of the law. The opinions, commentary and characterizations of cases provided on this blog are not legal advice and do not represent the opinions of Wolf Greenfield or its clients.