Even if the plaintiffs had standing, the defendant is still
entitled to summary judgment dismissing the action on the ground
that the defendant's system does not infringe the asserted
claims. Infringement analysis is a two-step process: "The first
step is determining the meaning and scope of the patent claims
asserted to be infringed. The second step is comparing the
properly construed claims to the device accused of infringing."
Markman v. Westview Instruments, Inc., 52 F.3d 967, 976
(Fed.Cir. 1995) (en banc) (citation omitted), aff'd
517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996).
Claim construction, the first step in infringement analysis, is
a matter of law. "The interpretation and construction of patent
claims, which define the scope of the patentee's rights under the
patent, is a matter of law exclusively for the court." Id., at
970-71. When the court interprets a patent, "[c]laims are to be
read and construed in light of the specification and the
prosecution history of the patent." ACS Hosp. Systems, Inc. v.
Montefiore Hosp., 732 F.2d 1572, 1577 (Fed.Cir. 1984). See also
Markman, 52 F.3d at 980. When possible, claims should be
construed in a manner that sustains their validity. See ACS
Hosp. Systems, 732 F.2d at 1577. In particular, "claims should
be read in a way that avoids ensnaring prior art if it is
possible to do so." Harris Corp. v. IXYS Corp., 114 F.3d 1149,
1153 (Fed.Cir. 1997). When construing a patent claim, a court may
consider extrinsic evidence, including "expert and inventor
testimony, dictionaries, and learned treatises," so that the
court may come "`to a correct conclusion' as to the `true meaning
of the language employed' in the patent." Markman, 52 F.3d at
980 (quoting Seymour v. Osborne, 78 U.S. (11 Wall.) 516, 546,
20 L.Ed. 33 (1870)).
The plaintiffs allege that the defendant is liable for patent
infringement under several theories. First, the plaintiffs allege
that the defendant has directly infringed the patents at issue.
Direct infringement is barred by 35 U.S.C. § 271(a), which
provides that "whoever without authority makes, uses, offers to
sell, or sells any patented invention, within the United States .
. . during the term of the patent therefor, infringes the
patent." To be liable for literal, direct infringement, a
defendant must duplicate each element of a patent claim exactly.
"Literal infringement requires that the accused device contain
each limitation of the claim exactly; any deviation from the
claim precludes a finding of literal infringement." Litton
Systems, Inc. v. Honeywell, Inc., 140 F.3d 1449, 1454 (Fed.Cir.
1998). See also Johnston v. IVAC Corp., 885 F.2d 1574, 1580
(Fed.Cir. 1989) ("Where a claim does not read on an accused
device exactly, there can be no literal infringement.").
In the alternative, the plaintiffs rely on the judicially
created "doctrine of equivalents." "A device that does not
literally infringe a claim may nonetheless infringe under the
doctrine of equivalents if every element in the claim is
literally or equivalently present in the accused device." Sage
Products, Inc. v. Devon Industries, Inc., 126 F.3d 1420, 1423
(Fed. Cir. 1997) (citing Pennwalt Corp. v. Du-rand-Wayland,
Inc., 833 F.2d 931, 934-35 (Fed.Cir. 1987) (en
banc)). To infringe under the doctrine of equivalents, the
accused device must "contain each limitation of the claim or its
equivalent." Overhead Door Corp. v. Chamberlain Group, Inc.,
194 F.3d 1261, 1269 (Fed.Cir. 1999) (citing Warner-Jenkinson Co.
v. Hilton Davis Chem. Co., 520 U.S. 17, 40, 117 S.Ct. 1040, 137
L.Ed.2d 146 (1997)). "An element in the accused product is
equivalent to a claim element if the differences between the two
are `insubstantial' to one of ordinary skill in the art." Id.,
194 F.3d at 1269 (quoting Warner-Jenkinson, 520 U.S. at 39-40,
117 S.Ct. 1040).
In order that patents retain their public notice function,
certain limits have been placed on the doctrine of equivalents.
See K-2 Corp. v. Salomon S.A., 191 F.3d 1356, 1366-67 (Fed.Cir.
1999); Sextant Avionique, S.A. v. Analog Devices, Inc.,
172 F.3d 817, 831 (Fed.Cir. 1999); Ethicon Endo-Surgery, Inc. v.
U.S. Surgical Corp., 149 F.3d 1309, 1316 (Fed.Cir. 1998). Thus,
under the so-called "all-elements" rule, "the doctrine of
equivalents must be applied to individual elements of the claim,
not to the invention as a whole." Warner-Jenkinson, 520 U.S. at
29, 117 S.Ct. 1040. Similarly, the concept of prosecution history
estoppel limits the range of possible equivalents. "Prosecution
history estoppel prevents operation of the doctrine of
equivalents from expanding a claim limitation to include subject
matter surrendered during the patent's prosecution." Elkay Mfg.
Co. v. Ebco Mfg. Co., 192 F.3d 973, 981 (Fed.Cir. 1999).
By force of prosecution history estoppel, "a patentee is
estopped from recovering through equivalency that which was
deemed unpatentable in view of the prior art." Pall Corp. v.
Micron Separations, Inc., 66 F.3d 1211, 1219 (Fed.Cir. 1995).
"In other words," the Court of Appeals has explained,
when an applicant, in response to an examiner's prior
art rejection, amends a claim by substituting one
limitation for another, the applicant cannot later
assert that the original limitation is an equivalent
of the substituted limitation. Thus, the doctrine
prevents the applicant from completely recapturing
the subject matter rejected by the examiner. In
addition, when an applicant narrows a claim element
in the face of an examiner's rejection based on the
prior art, the doctrine estops the applicant from
later asserting that the claim covers, through the
doctrine of equivalents, features that the applicant
amended his claim to avoid. . . . In addition, . . .
an applicant's arguments may constitute a clear and
unmistakable surrender of subject matter. Such
arguments preclude recapture of that subject matter.
Litton Systems, 140 F.3d at 1462. "Whether estoppel applies is
a question of law." Wang Laboratories, Inc. v. Mitsubishi
Electronics America, Inc., 103 F.3d 1571, 1578 (Fed.Cir. 1997).