Contradictory Positions Render Claims Indefinite
Before Prost, Clevenger, and Taranto. Appeal from the U.S. District Court for the District of Delaware.
Summary: Contradictory positions taken during prosecution and reexamination regarding the scope of the claims render the claims indefinite.
Infinity sued Oki Data in the District of Delaware asserting infringement of four related patents directed to using a fax machine as a printer or a scanner for a personal computer. Particularly, the claims include a connection between the computer and fax machine via a “passive link” without any intervening circuitry. The district court found that “passive link” was indefinite and entered final judgment of invalidity. Infinity appealed to the Federal Circuit.
The Federal Circuit agreed with the district court and found that Infinity’s contradictory positions during prosecution and during reexamination rendered the term “passive link” indefinite. During prosecution, Infinity distinguished a prior art reference by arguing that a fax machine connected to a device housed within a computer did not constitute a “passive link” between the fax machine and computer because the computer would receive a signal processed by the intervening device, rather than an uninterrupted signal from the fax machine. Later during ex parte reexamination of a continuation-in-part of the earlier application, Infinity sought to antedate a prior art reference by claiming priority to the parent application. In contrast to its original position, Infinity argued that the parent application’s depiction of a fax machine connected to a device housed within a computer did disclose a “passive link.” The Court concluded that the intrinsic evidence would leave a person of ordinary skill in the art without reasonable certainty as to the term “passive link” and thus affirmed the finding of indefiniteness.
Editor: Paul Stewart