CAFC: The ’108 patent is not related to the ’774 patent, but does disclose a purported improvement to the ’774 patent. While the ’108 patent may incorporate by reference the ’774 patent as prior art, it does not change the fact that the patents are not related.

Those facts don’t also don’t “change the fact” that the sky is blue. But they are certainly facts that are relevant to the construction of a claim term that appears in both patents, where that claim term isn’t expressly defined by the applicant.

More specifically, the the incorporation by reference of an earlier document will always be relevant to the construction of a term that appears in both the patent and the earlier document (at least in those cases where that term is not expressly defined by the patentee to exclude a definition given to the term in the earlier document). Likewise, a statement in the specification that the claimed invention is an improvement to an invention described in a prior document will always inform the construction of a term that appears in both the patent claim and in the description of the improved-upon embodiment in the prior document (at least in those cases where that term is not expressly defined by the patentee to exclude a definition given to the term in the earlier document).

There’s no way around that sort of common sense unless the CAFC is trying to erect some sort of wall around what facts can be considered in construing a claim term that has not been defined expressly or specifically by an applicant/patentee.

The ’108 patent discloses a separate invention, includes a distinct prosecution history, and is supported by a different written description—including Figures 3 and 4 which clearly depict RAM. These distinctions reinforce the well understood notion that claims of unrelated patents must be construed separately.

Those distinctions only “reinforce” the trivial point that differences between documents can lead to different claim constructions. When the same applicant uses the same term in the same technological field to describe some aspect of an invention, there is every reason to believe that the applicant is defining that term in the same way, regardless of the “relationship” between the documents. If there is evidence (other than self-serving boilerplate) to suggest that the applicant is not using the term in the same way then by all means it should be considered.

The key point here is that a requirement that claim terms in “separate” patent be construed “separately” doesn’t mean that the construction of the claim term in the prior patent isn’t relevant or can’t be considered by judges, jurists or potential defendants. That would make no sense whatsoever.

With respect to the collateral estoppel issue, the same considerations apply. Given two patents in “separate families”, collateral estoppel might very well apply to preclude re-litigation of claim construction of a particular term. It depends on the facts (e.g., the similarity between the cases and what the patentee argued in the first case).

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November 19, 2014 at 6:14 pm