In re NTP, Inc.

The patent application that would eventually become issued as U.S. patent no. 6,317,592 (the ’592 patent) was filed by NTP, Inc. (plaintiff) in December 1999 and claimed a priority date of May 20, 1991, through a series of continuation applications from an original application filed in September 1998 (the parent application). The claimed invention was an electronic-mail system that transmitted an email from an originating processor to a destination processor through a data-transmission network; the email message was transmitted using a gateway switch and an interface switch and, upon reaching a destination processor, was transmitted to a wireless device and then to a mobile processor. During reexamination proceedings, the patent-office examiner rejected all the ’592 patent’s claims as anticipated, obvious, lacking written description, or lacking enablement. The examiner found that the written description of the parent application did not support a “destination processor” that could retransmit the contents of an email, as was claimed in the ’592 patent. As a result, NTP was not entitled to a 1991 priority date. Furthermore, a prior-art reference, Lazaridis, had a filing date of May 29, 1998, and undisputedly anticipated all the claims of the ’592 patent unless the ’592 patent could claim an earlier priority date. The priority issue depended on the construction of “destination processor.” Before the board of patent appeals and interferences (the board) (defendant), NTP argued that “destination processor” could include gateway and interface switches and that, so construed, the parent application enabled the patented invention. The board construed destination processor as an “end node device” that allowed for immediate and direct physical access to email, distinct from gateway and interface switches. NTP appealed.