Amendments bridging the gap between the PTO’s broadest reasonable interpretation standard and the court’s narrower Phillips claim construction standard do not represent a substantial alteration of claim scope. Here, for example, amendments during reexamination clarifying that an “acoustic noise level” specifically corresponds to a “seek acoustic noise level” were found to be insubstantial for the purpose of intervening rights because the specification and original prosecution history already compelled this interpretation. “In the intervening rights analysis, our task is to interpret the scope of the claims per the Phillips standard.” It may therefore be helpful to couch amendments made during reexamination as merely conforming to the otherwise appropriate interpretation under the Phillips claim construction standard.

Background / Facts: The patents being asserted here are directed to reducing acoustic noise generated by the movement of a disk drive’s arm and read/write head, i.e., the seek process. The claims recite controlling a “seek acoustic noise level” of a data storage device. The word “seek” was added during an earlier reexamination to overcome a prior art rejection raised by the examiner under the PTO’s broadest reasonable interpretation of the claimed “acoustic noise level.”

Issue(s): Whether the added word “seek” substantially alters the scope of the claims so as to deprive the patentee of any intervening rights and corresponding damages between issuance of the original and reexamined claims.

Holding(s): No. “On their face, the original claims recite only ‘acoustic noise,’ which could encompass any manner of acoustic noise, including that generated from the spindle. But when read in conjunction with the remaining claim limitations and in light of the specification and prosecution history, a person of ordinary skill in the art would understand the claims to be limited to seek acoustic noise.” While the PTO may have “[a]ppl[ied] the broadest reasonable interpretation” during reexamination and “focused exclusively on the language of the claims at the expense of the clear language in the specification and prior examination history,” “[i]n the intervening rights analysis, our task is to interpret the scope of the claims per the Phillips standard.” “Thus, the examiner’s finding under the broadest reasonable interpretation that the claims are not limited to ‘seek acoustic noise’ cannot be dispositive,” and to the contrary “we conclude that the addition of the term ‘seek’ before ‘acoustic noise’ did not alter the scope of the claim.”

Full Opinion