According to its argument, Sage identified an interior part 40 as the first constriction, a second interior part 52 as the second constriction, and the space between them as the elongated slot. Based on this argument, the district court properly found no literal infringement. Even assuming that Sage has identified an elongated slot with a first constriction above it and a second constriction below it, that slot is not "at the top of the container body." Instead, as the undisputed drawing shows, Sage's proposed "elongated slot" on the Devon device lies within the container body. Because this deficiency prevents literal infringement, the district court properly granted summary judgment of no literal infringement.

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. See Pennwalt Corp. v. Durand-Wayland, Inc., 833 F.2d 931, 934-35, 4 USPQ2d 1737, 1739-40 (Fed.Cir.1987) (in banc). A claim element is equivalently present in an accused device if only "insubstantial differences" distinguish the missing claim element from the corresponding aspects of the accused device. Hilton Davis Chem. Co. v. Warner-Jenkinson Co., 62 F.3d 1512, 1517-18, 35 USPQ2d 1641, 1645 (Fed.Cir.1995) (in banc), rev'd on other grounds, --- U.S. ----, 117 S. Ct. 1040, 137 L. Ed. 2d 146 (1997). Although equivalence is a factual matter normally reserved for a fact finder, the trial court should grant summary judgment in any case where no reasonable fact finder could find equivalence. See Warner-Jenkinson Co. v. Hilton Davis Chem. Co., --- U.S. ----, ---- n. 8, 117 S. Ct. 1040, 1053 n. 8, 137 L. Ed. 2d 146 (1997) ("Where the evidence is such that no reasonable jury could determine two elements to be equivalent, district courts are obliged to grant partial or complete summary judgment."). The district court properly discerned that this case falls in that category.

Before the trial court, Sage reasserted its literal infringement argument as a basis for finding infringement as an equivalent. Sage also offered three other views of the accused products that a jury might adopt to find infringement by equivalents. Of Sage's four equivalence arguments, three of them identify element 40 as the accused "first constriction" and element 52 as the accused "second constriction" and place the "elongated slot" somewhere inside the container body.

The district court properly rejected all four of Sage's theories of infringement by equivalents. As the district court recognized, each theory suffers from one of two alternative problems--either the elongated slot is not substantially "at the top of the container body" or there is no first constriction that extends substantially "over said slot." The record does not show that Sage presented any perspective on Devon's accused devices that simultaneously satisfied an insubstantial variation of both of these limitations. Specifically, Sage's first three theories place the location of the "elongated slot" in this accused device far enough within the container body that, as a matter of law, no reasonable juror could find that it is located at substantially the "top of the container." Furthermore, the district court properly found that Sage's fourth theory of equivalence, identifying element 26 from the Devon patent drawing as the "first constriction," fails because element 26 is a hinged member that does not substantially "constrict access" to the slot, if at all.

Unable to conform its claim of infringement by equivalents to the strictures of the claim limitations, Sage essentially argues that having two constrictions below the top of the container is the same, for purposes of infringement, as having one constriction above and one constriction below. According to Sage, the claimed and accused arrangements accomplish substantially the same function, in substantially the same way, to achieve substantially the same result. However, the doctrine of equivalents does not grant Sage license to remove entirely the "top of the container" and "over said slot" limitations from the claim. See Warner-Jenkinson, at ----, 117 S. Ct. at 1049 ("It is important to ensure that the application of the doctrine, even as to an individual element, is not allowed such broad play as to effectively eliminate that element in its entirety."); Pennwalt, 833 F.2d at 936, 4 USPQ2d at 1741 ("[If] even a single function required by a claim or an equivalent function is not performed [by the accused device], the [district] court's finding of no infringement must be upheld."); Dolly, Inc. v. Spalding & Evenflo Cos., 16 F.3d 394, 400, 29 USPQ2d 1767, 1771 (Fed.Cir.1994) ("[T]he concept of equivalency cannot embrace a structure that is specifically excluded from the scope of the claims.").

The doctrine of equivalents prevents an accused infringer from avoiding infringement by changing only minor or insubstantial details of a claimed invention while retaining their essential functionality. See Hilton Davis, 62 F.3d at 1517, 35 USPQ2d at 1645 ("The Supreme Court in Graver Tank thus made insubstantial differences the necessary predicate for infringement under the doctrine of equivalents." (citing Graver Tank & Mfg. v. Linde Air Prods. Co., 339 U.S. 605, 70 S. Ct. 854, 94 L. Ed. 1097 (1950))); Charles Greiner & Co. v. Mari-Med Mfg., Inc., 962 F.2d 1031, 1036, 22 USPQ2d 1526, 1529 (Fed.Cir.1992) (discussing role of doctrine in preventing "fraud on a patent"); Texas Instruments, Inc. v. United States Int'l Trade Comm'n, 805 F.2d 1558, 1572, 231 U.S.P.Q. (BNA) 833, 842 (Fed.Cir.1986) ("The doctrine of equivalents ... exists solely for the equitable purpose of 'prevent[ing] an infringer from stealing the benefit of an invention.' " (internal citations omitted)). Applied more broadly, the doctrine would conflict with the primacy of the claims in defining the scope of a patentee's exclusive rights. See Warner-Jenkinson, at ----, 117 S. Ct. at 1049 ("[T]he doctrine of equivalents, when applied broadly, conflicts with the definitional and public-notice functions of the statutory claiming requirement."); Charles Greiner, 962 F.2d at 1036, 22 USPQ2d at 1529 (discussing the inherent conflict between the role of the doctrine in preventing "fraud on a patent" and the primacy of the claims in defining the scope of a patentee's exclusive rights). Thus, for a patentee who has claimed an invention narrowly, there may not be infringement under the doctrine of equivalents in many cases, even though the patentee might have been able to claim more broadly. If it were otherwise, then claims would be reduced to functional abstracts, devoid of meaningful structural limitations on which the public could rely. See, e.g., Conopco, Inc. v. May Dep't Stores Co., 46 F.3d 1556, 1562, 32 USPQ2d 1225, 1228 (Fed.Cir.1994) ("The doctrine of equivalents cannot be used to erase 'meaningful structural and functional limitations of the claim on which the public is entitled to rely in avoiding infringement.' " (internal citations omitted)).

Once again, this case raises the question of why the law restricts application of the doctrine of equivalents without further fact finding in some cases, see, e.g., id.; Dolly, 16 F.3d at 400, 29 USPQ2d at 1771, while in other cases the law imposes no such restriction, see, e.g., Hilton Davis Chem. Co. v. Warner-Jenkinson Co., 114 F.3d 1161, 1163-64, 43 USPQ2d 1152, 1154-55 (Fed.Cir.1997) (in banc) (after remand from the Supreme Court; order permitting factual analysis of equivalence to stand). The claim at issue defines a relatively simple structural device. A skilled patent drafter would foresee the limiting potential of the "over said slot" limitation.^* No subtlety of language or complexity of the technology, nor any subsequent change in the state of the art, such as later-developed technology, obfuscated the significance of this limitation at the time of its incorporation into the claim. See, e.g., Pennwalt, 833 F.2d at 938, 4 USPQ2d at 1742 ("[T]he facts here do not involve later-developed computer technology which should be deemed within the scope of the claims to avoid the pirating of an invention."). If Sage desired broad patent protection for any container that performed a function similar to its claimed container, it could have sought claims with fewer structural encumbrances. Had Sage done so, then the Patent and Trademark Office (PTO) could have fulfilled its statutory role in helping to ensure that exclusive rights issue only to those who have, in fact, contributed something new, useful, and unobvious. Instead, Sage left the PTO with manifestly limited claims that it now seeks to expand through the doctrine of equivalents. However, as between the patentee who had a clear opportunity to negotiate broader claims but did not do so, and the public at large, it is the patentee who must bear the cost of its failure to seek protection for this foreseeable alteration of its claimed structure. Cf. Maxwell v. J. Baker, Inc., 86 F.3d 1098, 1108, 39 USPQ2d 1001, 1007 (Fed.Cir.1996), cert. denied, --- U.S. ----, 117 S. Ct. 1244, 137 L. Ed. 2d 327 (1997) (discussing danger of allowing patentee to file and prosecute narrow claims and then, during the course of litigation, expand its exclusive rights under the doctrine of equivalents, thereby avoiding examination of the broad subject matter).

This court recognizes that such reasoning places a premium on forethought in patent drafting. Indeed this premium may lead to higher costs of patent prosecution. However, the alternative rule--allowing broad play for the doctrine of equivalents to encompass foreseeable variations, not just of a claim element, but of a patent claim--also leads to higher costs. Society at large would bear these latter costs in the form of virtual foreclosure of competitive activity within the penumbra of each issued patent claim. Because the doctrine of equivalents blurs the line of demarcation between infringing and non-infringing activity, it creates a zone of uncertainty, into which competitors tread only at their peril. Cf. Markman v. Westview Instruments, Inc., 517 U.S. 370, ----, 116 S. Ct. 1384, 1396, 134 L. Ed. 2d 577 (1996) (discussing the importance of certainty in defining the scope of exclusive rights). Given a choice of imposing the higher costs of careful prosecution on patentees, or imposing the costs of foreclosed business activity on the public at large, this court believes the costs are properly imposed on the group best positioned to determine whether or not a particular invention warrants investment at a higher level, that is, the patentees.

In sum, the '728 patent claims a precise arrangement of structural elements that cooperate in a particular way to achieve a certain result. Devon achieves a similar result--restricted entry to a medical disposal container--but it does so by a different arrangement of elements. Because this issued patent contains clear structural limitations, the public has a right to rely on those limits in conducting its business activities. This court will not effectively remove such a limitation under a doctrine designed to prevent "fraud on a patent." Accordingly, this court affirms the judgment of the district court that Devon does not infringe the '728 patent, either literally or under the doctrine of equivalents.

As a final matter, Sage presents this court with new infringement arguments, raised for the first time on appeal. In short, Sage argues that "elongated slot" really means the three dimensional space that extends from immediately above the claimed container down into its center or alternatively, the "container body" does not extend all the way to the top of Devon's accused device. The arguments show a misunderstanding of the role of this court. This is an appellate court. By and large, it is our place to review judicial decisions--including claim interpretations and grants of summary judgment--reached by trial courts. No matter how independent an appellate court's review of an issue may be, it is still no more than that--a review. With a few notable exceptions, such as some jurisdictional matters, appellate courts do not consider a party's new theories, lodged first on appeal. If a litigant seeks to show error in a trial court's overlooking an argument, it must first present that argument to the trial court. In short, this court does not "review" that which was not presented to the district court. Accordingly, this court declines to consider Sage's novel infringement arguments.

III.

Sage's '849 patent covers a needle removal and disposal device. Figures 1 and 3 of the '849 patent illustrate the claimed device.

NOTE: OPINION CONTAINS TABLE OR OTHER DATA THAT IS NOT VIEWABLE

A container 10 has two baffles 11 and 12 that are used to close the container. Each baffle 11 or 12 has an opening 15 or 16 through which expendable items, such as used syringes, can be deposited. As discussed below, the claim requires that the openings be horizontally offset from one another to minimize the chance of a user coming into contact with previously deposited waste.

Claim 1, the only independent claim of the '592 patent, reads (with emphasis to highlight disputed limitations):

1. A receptacle for receiving expendable items, said receptacle including a container, a first baffle generally closing the top of said container and defining a first opening through said first baffle of such size and shape to receive said expendable items therethrough, a second baffle disposed below said first baffle, said second baffle defining a second opening therethrough of such size and shape to receive said expendable items, said second opening being horizontally displaced from said first opening, said first baffle and said second baffle defining a space therebetween sufficient to allow said expendable items to pass through said first opening, between said first baffle and said second baffle, and through said second opening to be received within said container.

For purposes of summary judgment, the parties have focused their dispute on the highlighted portions of the claim, specifically, the requirements (1) that the first and second openings pass "through" the first and second baffles, and (2) that the first and second openings be horizontally displaced from one another so that deposited waste travels laterally as it passes through the space between the two baffles. On these points, the district court properly interpreted the claims.

First, the claim requires that the first and second openings pass "through" the first and second baffles. The district court properly construed this term to mean that each opening extends from one side of the baffle to the other. See Webster's Third New International Dictionary (1981) (defining "through" as "into at one side or point and out at another, especially the opposite side of") (quoted by district court). Although there are other possible meanings for "through," including one cited by Devon that means something more like "allowing passage," these definitions are not used in connection with an "opening through" another structure, such as a baffle. Thus, the ordinary meaning of the claim term "through," which controls in the absence of an extraordinary usage by the patentee, see York Prods., 99 F.3d at 1572, 40 USPQ2d at 1622, requires that the first and second openings pass from one side of each baffle to the other.

The written description confirms this straightforward construction of the claim language. There, the patentee shows openings that pass "through" the baffles--that is from one side of each baffle to the other. See '592 patent, figures 1-6. Also, in describing the operation of the claimed receptacle, the written description says that "an item can be placed through the opening 15 as shown by the arrows [in Figure 3]." See id., col. 3, lines 39-41. The arrows shown in Figure 3 demarcate a path passing from one side of baffle 15 through the baffle to the other side of baffle 15. Finally, the written description also teaches forming the openings by "cutting" the baffle. See id., col. 3, lines 1-2. Such "cutting" would not be needed if, as Devon avers, "through" merely meant "past."

Finally, the prosecution history does not show any unique usage of the word "through" that would contradict its plain meaning. Rather, during the prosecution of the application leading to the '592 patent, the applicant referred to each baffle as a "flap having a hole therethrough." Amendment, filed August 3, 1981, p. 3 (emphasis added). That is, the applicant used the word "hole" as a synonym for "opening," thereby clearly indicating that an "opening through [a] baffle" extends from one side of the baffle to the other.

The district court also properly construed the claims to require a horizontal offset between the first and second openings, so that deposited waste passes through the first opening, then through a space between the baffles in which it must travel laterally, and finally through the second opening. In this regard, the claim requires that the "second opening be[ ] horizontally displaced from said first opening."

Under that correct construction, Sage's products do not infringe. The parties agree that the preferred embodiment of the '728 patent accurately depicts Sage's accused products. That embodiment, altered to show Devon's infringement allegations, is shown below:

NOTE: OPINION CONTAINS TABLE OR OTHER DATA THAT IS NOT VIEWABLED.Ct. Mem. & Order (Sept. 14, 1994), p. 29.

Even if a jury found that Sage's first and second curved cowls (labeled 18 and 20) are "baffles" as required by the claims of the '592 patent, no reasonable jury could find that the second baffle has an opening that passes "through" it. At best, the second opening identified by Devon on the above figure is "adjacent" the accused baffle, whereas the claim requires that the opening go through the baffle. Moreover, even accepting Devon's identification of first and second openings (as labeled above), there is no horizontal displacement between the first and second accused openings such that deposited material must move sideways before falling through the second opening. Rather, the "first opening" identified by Devon overlies entirely the "second opening." Without the claimed horizontal displacement between the two openings, a needle dropped at the center of the arc formed by Sage's cowls would pass directly through the first and second openings identified by Devon without ever traveling in a horizontal direction. Thus, the district court properly concluded that Sage's accused products do not literally infringe the '592 patent.

Turning to the doctrine of equivalents, this court must determine whether the claim elements literally missing from the accused products may nonetheless be present by equivalents. See Warner-Jenkinson, at ----, 117 S. Ct. at 1049. Sage's accused products do not literally infringe the '592 patent because (1) the second opening is not "through" the second baffle, and (2) the displacement between the first and second openings does not necessarily cause deposited waste to travel horizontally on its fall into the receptacle. The prosecution history of the application that led to the '592 patent reveals the importance of these limitations and reveals why, as a matter of law, there can be no infringement in this case.

The examiner rejected all claims of the application, as originally filed, over U.S. Patent No. 4,121,755 (the Meseke prior art patent). See Examiner's Action (May 6, 1981). The examiner also cited two other references that showed relevant features, U.S. Patent Nos. 1,603,024 (the Childs prior art patent) and 3,226,007 (the Thies prior art patent). Id. To distinguish the cited art, the applicant amended the claims to require that the second baffle have an opening therethrough, that the first and second openings be horizontally displaced from one another, and that there be a space defined by the baffles. The applicant then explained:

It is thought that claim 1 now precisely claims the truly novel aspect of the device of the present invention since claim 1 claims the container having two baffles, or box flaps, closing the top of the box, each of the flaps having a hole to receive items to be placed into the box, but the holes are offset and there is a space between the two flaps to allow the items to pass through the first hole, sideways, and through the second hole.

[The Meseke prior art patent] discloses two flaps closing the top of the box only when the box has been filled and the flaps permanently close the opening. Thus, there can be no arrangement as is now claimed in claim 1.

[The Childs prior art patent] discloses two flaps across the top of a box, but the flaps are contiguous and the holes through the two flaps are aligned. Thus, [the Childs prior art patent] does not disclose the arrangement claimed in claim 1.

Amendment (Aug. 3, 1981), p. 3-4 (emphasis added).

This passage shows that the applicant surrendered some claim scope in exchange for issuance of the '592 patent. Specifically, before the examiner's required amendments, the claims covered containers that used a second baffle without an opening. However, the claim amendments specifically added this requirement, making it clear that one could not infringe the claim without an opening through the second baffle. Likewise, the original claims covered containers with a first opening directly overlying a second opening. However, the applicant surrendered that coverage in order to overcome prior art rejections, and limited the claims to containers with a horizontal offset between the first and second openings.

A patentee is not free to retrade or renege on a deal struck with the PTO during patent prosecution. See Mark I Marketing Corp. v. R.R. Donnelley & Sons, Co., 66 F.3d 285, 291-92, 36 USPQ2d 1095, 1099-1100 (Fed.Cir.1995), cert. denied, 516 U.S. 1115, 116 S. Ct. 917, 133 L. Ed. 2d 847 (1996). When an applicant distinguishes prior art by surrendering some previously-claimed subject matter, the patentee may not later seek to recover that surrendered subject matter by the doctrine of equivalents. See id.; see also Warner-Jenkinson, at ---- - ----, 117 S. Ct. at 1049-50. The '592 patent can only reach Sage's accused products if waste being deflected by, as opposed to passing through, a baffle is within a legally permissible range of equivalents. As set out by the prosecution history above, it is not. By the same token, the '592 patent can only reach Sage's accused products if having a first opening directly above a second opening, as opposed to horizontally displaced, is within a legally permissible range of equivalents. Again, it is not. Thus, the district court properly determined that there could be no infringement under the doctrine of equivalents.

V.

In accordance with this opinion, this court affirms the district court's summary judgment of non-infringement on all three patents.

COSTS

Each party shall bear its own costs.

AFFIRMED.

* This court does not imply that Sage's representation before the Patent and Trademark Office was inadequate. To the contrary, it appears that the claim precisely defines the structure elaborated in the written description and drawings. The public record reflects a manifest intention to claim this structure and no more. Whether actual or constructive, that intention now binds Sage.