Construing Claims as of their Effective Filing Date

A short aside from Dennis Crouch

In Phillips v. AWH, the en banc Federal Circuit included an oddball statement regarding PHOSITA perspective in claim construction.  The court wrote that the focus is on the meaning to PHOSITA “at the time of the invention, i.e., as of the effective filing date of the patent application.”  I call the statement odd because it incorrectly states that the time-of-the-invention is the same as the patent application’s effective-filing-date. The difference can be critical — although word-meaning changes slowly over time, recent invention is an important trigger for rapid definitional change.

Regardless of whether the Phillips statement is correct, going forward for Post-AIA patents, the court should now eliminate “the time of the invention” from its claim construction process.  Under the statute, all of the focus now is on the effective filing date with invention shifted to a mere historic element of the patenting process.

Stepping Back: One problem with any time-of-the-invention analysis is that the traditional legal definition of invention involves a potentially wide temporal expansion.  Remember, invention begins with conception but is not completed until the invention is reduced to practice.  The patent courts added further to this by finding the filing of a patent application to be a constructive reduction to practice that completes the invention process. Because most patent applications are filed prior to a complete reduction to practice, for most patented inventions the time of invention completion is the same as the effective filing date of the patent at issue.