The opinion of the court was delivered by: ASPEN
MARVIN E. ASPEN, Chief Judge:
The plaintiffs sued defendant Protel, Inc. in 1997, alleging that Protel's pay telephone monitoring system infringes the Polillo patent. Protel has moved for summary judgment of noninfringement.
Many patents, like the one in this case, describe in their claims a device or system which is composed of not one discrete invention but rather of a number of components, known as elements, which comprise the patented whole. The Polillo patent's claims describe a vending machine monitoring system, the elements of which include a "receptacle collection counter," a "receptacle time-out second counter," and other "registers" which collect information about the machine's operation. Id. at Col. 8, lines 49-51. These elements are at the core of our analysis, for a finding of infringement requires that every element in the claim (or its equivalent, as we discuss in Part B., infra) appear in Protel's accused device. See Warner-Jenkinson Co., Inc. v. Hilton Davis Chem. Co., 520 U.S. 17, 137 L. Ed. 2d 146, 117 S. Ct. 1040, 1049 (1997). Conversely, if it is clear that any elements (or their equivalents) are not found within the accused device, summary judgment for the defendant is appropriate. See 117 S. Ct. at 1053 n.8.
The first step of the literal infringement analysis requires that we construe the patent's claims, which serves to define in clear terms the scope of the patent's coverage. See Markman v. Westview Instruments, Inc., 517 U.S. 370, 116 S. Ct. 1384, 1387, 134 L. Ed. 2d 577 (1996); Lockwood v. American Airlines, Inc., 107 F.3d 1565, 1573 (Fed. Cir. 1997). Our primary focus is on the language of the claims, though we may also consult the patent specifications, the prosecution history, and, if necessary, extrinsic evidence which does not contradict the express provisions of the patent. See Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582-83 (Fed. Cir. 1996).
We need go no further than the language of the Polillo patent's claims in order to construe the element which serves as the sole focus of this opinion, the receptacle collection counter. The first claim (the only independent claim) describes, inter alia, a "monitoring unit . . . having a non-volatile memory and located with and coupled to" a vending machine, and it states that this monitoring unit "has a register bank containing . . . a receptacle collection counter." Polillo, Col. 8, lines 36-49. The seventh claim (a dependent claim) states that this counter "counts the number of times the coin box of the coin machine is removed from the machine," id. at Col. 9, lines 26-28, and the seventeenth claim (another dependent claim) further states that "the coin box register increases by one" for "each time the coin box is removed from the pay phone," id. at Col. 10, lines 45-46. The first claim also describes a "polling and display unit" capable of "interrogating each . . . monitoring unit" to collect this information. Id. at Col. 8, lines 41-44. From all of this it is clear that the Polillo patent describes a vending machine monitoring system in which (1) a device located inside each vending machine counts and stores the total number of times that the collector has removed the coin box from the machine; and (2) a central computer may, at its user's request, collect the accumulated information from the device.
B. The Doctrine of Equivalents and Prosecution History Estoppel
Of course, even if Protel's pay telephones do not literally contain each element of the Polillo patent's claims, Protel is still liable if its monitoring system contains the substantial equivalent of every element. This is the familiar doctrine of equivalents, the validity and vitality of which the Supreme Court reaffirmed just last year. See Warner-Jenkinson, 117 S. Ct. at 1045.
The doctrine does not operate, however, where the patent holder amended the claims during prosecution "to avoid the prior art, or otherwise to address a specific concern -- such as obviousness -- that arguably would have rendered the claimed subject matter unpatentable." Id. at 1049. This "well established limit on non-literal infringement" is known as "prosecution history estoppel" or "file wrapper estoppel." Id. And while application of the doctrine of equivalents to the accused device appears to be a question of fact to be decided by the jury, see, e.g., Hilton Davis Co. v. Warner-Jenkinson Co., Inc., 62 F.3d 1512, 1520-21 (Fed. Cir. 1995) (so holding); see also Warner-Jenkinson, 117 S. Ct. at 1053 (noting that "there was ample support in our prior cases for that holding" but reserving judgment on the question), "legal limitations on the application of the doctrine" such as prosecution history estoppel can justify "complete judgment . . . by the court, as there would be no further material issue for the jury to resolve." Warner-Jenkinson, 117 S. Ct. at 1053 n.8; see also Hoganas AB v. Dresser Indus., Inc., 9 F.3d 948, 952 (Fed. Cir. 1993) ("prosecution history estoppel is a question of law").
We believe that prosecution history estoppel bars the plaintiffs from claiming substantial equivalence as to the receptacle collection counter element. In the original patent application, claim one did not explicitly mention that element, claim seven stated that the "register bank has a storage register to count the number of times the coin box of the coin machine is removed from the machine," and claim seventeen (then numbered claim eighteen) appeared in its present form. The examiner rejected each of the proposed Polillo claims, stating that claims four through eighteen were obvious in light of Patent 4,124,775, also known as the "Zarouni" patent. Examiner's Report p.2 (citing 35 U.S.C. § 103). The Zarouni patent's first claim describes "[a] coin box removal information processing arrangement for a coin telephone station" which contains "circuitry responsive to a removal of said coin box" and an "apparatus responsive to an interrogation signal from the central office during a call from said station." Zarouni, Col. 10, lines 1-19. In plain English, this means that a Zarouni pay telephone notifies the central office at the conclusion of the next telephone call which follows the removal of the coin box. A Zarouni pay telephone does not remember the total number of removals.
The Polillo applicants amended their claims, adding to count one the language stating that the monitoring unit contained the receptacle collection counter and changing count seven to its present form. In addition, the Polillo applicants made ...