Functional method claim : CAFC Alert

Make Sure Patent Claims Do Not Contain an Impossibility

| March 12, 2021

Synchronoss Technologies, Inc., v. Dropbox, Inc.

February 12, 2021



       Synchronoss Technologies appealed the district court’s decisions that all asserted claims relating to synchronizing data across multiple devices are either invalid or not infringed. The Federal Circuit affirmed the district court’s judgments of invalidity under 35 U.S.C. § 112, paragraph 2, with respect to certain asserted claims due to indefiniteness. The Federal Circuit also found no error in the district court’s conclusion that Dropbox does not directly infringe by “using” the claimed system under § 271(a). Thus, the Federal Circuit affirmed on non-infringement.


       Synchronoss sued Dropbox for infringement of three patents, 6,757,696 (“’696 patent”), 7,587,446 (“’446 patent”), and U.S. Patent Nos. 6,671,757 (“’757 patent”), all drawn to technology for synchronizing data across multiple devices.

       The ’446 patent discloses a “method for transferring media data to a network coupled apparatus.” The indefinite argument of Dropbox targets on the asserted claims that require “generating a [single] digital media file” that itself “comprises a directory of digital media files.” Synchronoss’s expert conceded that “a digital media file cannot contain a directory of digital media files.” But Synchronoss argued that a person of ordinary skill in the art “would have been reasonably certain that the asserted ’446 patent claims require a digital media that is a part of a directory because a file cannot contain a directory.” The district court rejected the argument as “an improper attempt to redraft the claims” and concluded that all asserted claims of the ’446 patent are indefinite.

       The ’696 patent discloses a synchronization agent management server connected to a plurality of synchronization agents via the Internet. The asserted claims of the ‘696 patent all include the following six terms, “user identifier module,” “authentication module identifying a user coupled to the synchronization system,” “user authenticator module,” “user login authenticator,” “user data flow controller,” and “transaction identifier module.” The district court concluded that all claims in the ’696 patent are invalid as indefinite. The decision leaned on the technical expert’s testimony that all six terms are functional claim terms. The specification failed to describe any specific structure for carrying out the respective functions.

       The asserted claim 1 of ‘757 patent recites “a system for synchronizing data between a first system and a second system, comprising …” The district court found that hardware-related terms appear in all asserted claims of ‘757 patent. The hardware-related terms include “system,” “device,” and “apparatus,” all that means the asserted claims could not cover software without hardware. Dropbox argued that it distributed the accused software with no hardware. The district court granted summary judgment of non-infringement in favor of Dropbox.


i. The ‘446 Patent – Indefiniteness

       The Federal Circuit noted that the claims were held indefinite in circumstances where the asserted claims of the ’446 patent are nonsensical and require an impossibility—that the digital media file contains a directory of digital media files. As a matter of law under § 112, paragraph 2, the claims are required to particularly point out and distinctly claim the invention. “The primary purpose of this requirement of definiteness of claim language is to ensure that the scope of the claims is clear so the public is informed of the boundaries of what constitutes infringement of the patent.” (MPEP 2173)

       Synchronoss argued that a person of ordinary skill would read the specification to interpret the meaning of the media file. However, the Federal Circuit rejected the argument since Synchronoss’s proposal would require rewriting the claims and also stated that “it is not our function to rewrite claims to preserve their validity.”

ii. The ‘696 Patent – Indefiniteness

       The ‘696 patent was focused on whether the claims at issue invoke § 112, paragraph 6.  The Federal Circuit applied a two-step process for construing the term, 1. identify the claimed function; 2. determine whether sufficient structure is disclosed in the specification that corresponds to the claimed function.

       However, the asserted claims were found not to detail what a user identifier module consists of or how it operates. The specification fails to disclose an “adequate” corresponding structure that a person of ordinary skill in the art would be able to recognize and associate with the corresponding function in the claim. The Federal Circuit held that the term “user identifier module” is indefinite and affirmed the district court’s decision that asserted claims are invalid.

iii. The ‘757 Patent – Infringement

       The ‘757 patent is the only one focused on the infringement issue. Synchronoss argued that the asserted claims recite hardware not as a claim limitation but merely as a reference to the “location for the software.” However, the Federal Circuit affirmed the district court’s founding that the hardware term limited the asserted claims’ scope.

       The Federal Circuit explained that “Supplying the software for the customer to use is not the same as using the system.” Dropbox only provides software to its customer but no corresponding hardware. Thus, the Federal Circuit affirmed the district court’s summary judgment of non-infringement.


  • Make sure patent claims do not contain an impossibility
  • Supplying software alone does not infringe claims directed to hardware.
  • “Adequate” structures in the specification are required to support the functional terms in the claims.

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