Patent Law

Disclaimed

By Gary Odom and Jordan Kuhn

RFID Tracker sued Wal-Mart and others for infringing 6,967,563, claiming an RFID reader. The district court judge construed the claim to exclude the RFID reader from also being a transmitter, owing to prosecution disclaimer. Hence, the defendants could not be tagged for infringement, because their reader included a transmitter. RFID Tracker trekked to appeal.

RFID Tracker v. Wal-Mart Stores and Gilette and Target (CAFC 2008-1412) non-precedential

Technology background -

The '563 patent, issued on November 22, 2005, discloses an inventory control system that includes radio frequency identification ("RFID") tags attached to inventory items, an interrogator/reader, and a computer. The interrogator/reader generates a radio frequency ("RF") field sufficient to activate every RFID tag within the field range. Once activated, the RFID tags, which contain anti-collision capabilities, communicate their unique code to the interrogator/reader. The interrogator/reader communicates the unique code to the computer. The computer includes a list of identifiers for each inventory item, unique codes for each RFID tag, and an item status for each inventory item. It sets the item status to true or "present" for inventory items associated with received unique codes and sets the item status to false or "absent" for inventory items from which the computer does not receive unique codes.

The gospel on prosecution disclaimer -

The prosecution history must be reviewed when interpreting a claim to "exclude any interpretation" that was "disclaimed or disavowed during prosecution." Computer Docking Station Corp. v. Dell, Inc., 519 F.3d 1366, 1374-75 (Fed. Cir. 2008); ZMI Corp. v. Cardiac Resuscitator Corp., 844 F.2d 1576, 1580 (Fed. Cir. 1988). "A patentee may limit the meaning of a claim term by making a clear and unmistakable disavowal of scope during prosecution." Computer Docking, 519 F.3d at 1374.

If the applicant unequivocally disavows claim scope, the doctrine of prosecution disclaimer applies even if the disclaimer results in a negative claim limitation. See N. Am. Container, Inc. v. Plastipak Packaging, Inc., 415 F.3d 1335 (Fed. Cir. 2005) (affirming district court's construction of claim term "generally convex" to require "a majority of convex points along the inner wall and no concave points," as the applicant's statements in the prosecution history disclaimed coverage of an inner wall with any concavity). Prosecution disclaimer may also arise from an applicant's statements in a parent patent application if the parent application relates to the same subject matter as the claim language at issue. Ormco Corp. v. Align Tech., Inc., 498 F.3d 1307, 1314 (Fed. Cir. 2007).

The CAFC's claim of disclaimer -

The applicant differentiated its claims from this prior art on the ground that the claimed interrogator/reader was simple, unlike the complex readers of the prior art that contained and used a transmitter to send commands to the tags.

In light of these statements during prosecution, RFID cannot now contend that the claimed interrogator/reader is anything more than "simply a receiver and a field generator in its simplest form." See Computer Docking, 519 F.3d at 1376-70 ("portable computer" limitation in preamble of claim determined to mean "a computer without a built-in display or keyboard" due to prosecution statements distinguishing prior art as "requiring a portable display and keyboard," whereas the invention did not require a built-in display and keyboard); Innovad Inc. v. Microsoft Corp., 260 F.3d 1326, 1332 (Fed. Cir. 2001) (despite lack of explicit claim limitation prohibiting device from having a keyboard, devices with keyboard were beyond scope of the claims due to disclaimer in specification).

Affirmed.

Full post as published by The Patent Prospector on August 19, 2009 (boomark / email).