The Claims Interpreted Report

“At Least One Piece” Can Mean the Whole Thing

By Chris Francis

Categories: The Claims Interpreted Report

The Federal Circuit held that the broadest reasonable interpretation of “at least one piece” of a computer file can include the entire computer file in the absence of further limitation in the claim or definition in the specification. AC Technologies v., Inc. (Appeal No. 218-1433; Decided January 9, 2019).

The patent at issue is directed toward storing copies of data across a network to improve data integrity and reduce network lag. To accomplish this, the system copies data redundantly across the network.  The relevant claim at issue reads:

1. A data management system comprising:

at least one computer unit that stores at least one complete file, each file including a plurality of individual pieces, the pieces containing parts of the files, wherein at least one piece is stored in a redundantmanner in the at least two data storageunits;


In the underlying IPR, which was appealed in this case, the patent holder argued that the claim must be properly construed to require redundantly storing file pieces, not the complete file.  The Board reasoned that because the independent claim recites “at least one piece,” the claims contemplate copying and storing more than one piece of a file, including up to an entire file.  Since the prior art disclosed copying entire files on more than one host, the Board invalidated claim 1 using this interpretation. 

The Federal Circuit affirmed the Board, first looking at the claims themselves and noting that “the claims impose no limit on how the system stores or copies pieces and they do not require storing or copying pieces on an individual basis or prohibiting it storing or copying pieces ‘contiguously with other pieces on the same file.’”  In other words, the claims do not limit how many pieces of the file the system may copy and store. 

Next looking to the specification, the Federal Circuit noted that the specification discloses “distribution of the entire data,” not merely specific pieces.  The specification does disclose storing pieces of data but notes that those disclosures are directed to particular embodiments and the specification never disclaims whole-file storage.  In this light, the Court declined to import a limitation from the specification into the claims in accordance with In re Van Geuns, 988 F.2d 1181(Fed. Cir. 1993).