Saying an "interrogator/reader" does "no transmission," means an "interrogator/reader" does not include a transmitter

RFID Tracker sued a number of retailers (Wal-Mart, Gillette, and Target) for alleging infringing U.S. Patent No. 6,967,563, a patent disclosing an inventory control system which includes radio frequency identification ("RFID") tags attached to the inventory to be managed. Claim 1 includes the following limitation:

an interrogator/reader in communication with the computer and including:

a field generator...; and

a receiver,

The parties disagreed as to the meaning of "interrogator/reader." RFID argued this term required no construction, while Wal-Mart, Gillette & Target construed the term to "a field generator and a receiver, but not a transmitter." The Court adopted Defendant's construction. RFID stipulated to non-infringement, and appealed the construction up to the Federal Circuit.

The Court explained 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).

In response to an obviousness rejection under 35 U.S.C. § 103(a), the applicant had argued that the present invention is "simply a receiver and a field generator in its simplest form," and that the claimed method "requires no polling and no transmission from the interrogator/reader." As such, "RFID cannot now contend that the claimed interrogator/reader is anything more..."

Decision affirmed.

Relevant documents:

• Claim construction order.

RFID Tracker, Ltd. v. Wal-Mart Stores, Inc., Case No. 2008-1412 (Fed. Cir. Aug. 18, 2009) (nonprecedential)