For prosecution history estoppel to apply, the patentee must make a “clear and unmistakable” disavowal of claim scope. “The election of an invention in response to an ambiguous restriction requirement in turn cannot be said to provide any guidance forming a basis for narrowing a broadly drafted claim.” That is not to say, however, that an unambiguous election will not be narrowing, and one should therefore take care to address more direct statements by the PTO about the characteristics of an elected species or at least provide a disclaimer as to the PTO’s particular findings.

Background / Facts: The patent here is directed to a “concha-style” headset for transmitting received sounds to the ear of a user (e.g., headsets used with cell phone receivers). The concha is part of the human ear and used by this type of device to stabilize the headset during operation, hence the name concha-style. In this regard, the claims recite a “stabilizer support member” and a “concha stabilizer,” several designs of which are disclosed in the application, ranging from an “elongated” structure to an “arch” structure. While the application that gave rise to the patent initially contained a variety of claims covering numerous structures, the patent itself focuses on the embodiments of figures 1A and 1B due to a PTO-initiated restriction requirement during prosecution in which the patentee was instructed to elect among what the PTO viewed as multiple inventions – identified by the PTO as corresponding to different figures.

Issue(s): Whether the terms “stabilizer support member” and “concha stabilizer” should be given a narrower interpretation as “elongated” members as depicted in figures 1A and 1B of the disclosure on account of the patentee’s election during prosecution to prosecute the species of figures 1A and 1B.

Holding(s): No. For prosecution history estoppel to apply, the patentee must make a “clear and unmistakable” disavowal of claim scope during prosecution to overcome the “heavy presumption that claim terms carry their full ordinary and customary meaning.” Here, the patentee’s “election of species of Figures 1A and 1B did not amount to such a surrender of claim scope. The PTO’s restriction requirement did not suggest that the different inventions it found were based on differences in structure (i.e., ‘elongated’ versus an ‘arch’). Indeed, the PTO found four patentably distinct inventions in the figures of the … patent without providing any reasons why in its view the application presented differing inventions. Likewise, other figures of the … patent depicting other unelected species of the invention also reveal a ‘stabilizer support’ that appears ‘elongated,’ which refutes [the] contention that the restriction requirement was based on that structural difference. The election of an invention in response to an ambiguous restriction requirement in turn cannot be said to provide any guidance forming a basis for narrowing a broadly drafted claim.”

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