Prosecution Disclaimer: Another Reexamination Trap

by Dennis Crouch

Grober v. Mako Products (Fed. Cir. 2012)

In 2006, David Grober won an academy award for the best technical achievement of the year for his “perfect horizon” camera stabilization head.  The camera head is designed to compensate for motion during land, air, and sea operations of a camera.  Grober’s patent No. 6,611,662 covers the camera head and is the subject of this appeal.

This case is like many that involve parallel legal proceedings.  Grober filed an infringement action in 2004, Mako then filed an inter partes reexamination request – asking the USPTO to take a fresh look at the patent.  The district court stayed the litigation until 2006. At that time, the court became antsy and reopened the case.  After claim construction, the district court ruled that the accused products did not infringe the asserted claims and dismissed. Later, during the course of the appeal, the USPTO finally decided the reexamination by confirming the patentability of the asserted claims.

The primary issue on appeal is the construction of the claim term “payload platform.”  The district court narrowly construed the term as limited to a “horizontal surface” and that consequently led to a non-infringement holding.   To reach its conclusion, the district court highlighted Grober’s statements made to the PTO in the pending reexamination.

In reviewing the claim construction de novo, the appellate panel agreed that statements made in an ongoing, pending reeexamination were relevant to the claim construction.  See Krippelz v. Ford (Fed. Cir. 2012). In this case, however, the Federal Circuit held that the reexamination statements were not direct enough to constitute prosecution disclaimer.

Grober’s statements were not an unambiguous disavowal that clearly and unmistakably disclaims claim scope or meaning. In this instance, the reexamination history did not define or limit, let alone clearly and unmistakably disclaim, claim scope.

The appellate court’s approach here looked particularly to the words used by to the patentee in the reexamination to identify any actual limitations or disclaimers and refused to read-between-the-lines to find implied disclaimers.  In this sense, the decision supports the long-held prosecution strategy of keeping the prosecution history file thin. 

The Federal Circuit then offered its own broader construction of the term and remanded the case for reconsideration.

Comment: Although Grober may have escaped, this case highlights one of many ways that a parallel reexamination can serve as a trap for a plaintiff-patentee.  These traps go well beyond the straightforward risk of having claims cancelled or narrowed.