United States Court of Appeals for the Federal Circuit
November 16, 1999
MIDDLETON, INC., PLAINTIFF-APPELLANT,
MINNESOTA MINING & MANUFACTURING COMPANY, DEFENDANT-APPELLEE.
Before Lourie, Clevenger, and Rader, Circuit Judges.
The opinion of the court was delivered by: Clevenger, Circuit Judge.
Middleton, Inc. (Middleton) appeals the decision of the United States District Court for the Northern District of Illinois, granting summary judgment of noninfringement in favor of Minnesota Mining & Manufacturing Co. (3M). See Middleton, Inc. v. Minnesota Mining & Mfg. Co., No. 96-C6781, slip op. at 13 (N.D. Ill. Nov. 24, 1998). The district court determined, based on its claim construction, that no reasonable jury could find that 3M's product--"FloorMinders"--infringes Middleton's U.S. Patent No. 4,944,514, either literally or under the doctrine of equivalents. Because the district court's claim construction was erroneous with respect to the limitation "material for finishing," we vacate on the basis of that limitation and remand the case for further proceedings.
Middleton is the owner of U.S. Patent No. 4,944,514 (the `514 patent), entitled "Floor Finishing Material and Method." The `514 patent discloses the use of an adhesive-backed flexible sheet for finishing smooth floor surfaces, such as athletic courts, bowling lanes, and commercial and residential floors of wood, linoleum, terrazzo and concrete. The specification teaches that appropriate boundary lines, team logos, and other such markings may be applied to the undersurface of the adhesive finishing sheet prior to applying the finishing sheet to the floor. See `514 patent, col. 5, lines 61-68.
The application that matured into the `514 patent is a continuation-in-part of two parent applications, which, in turn, derive from a common grandparent. The grandparent application is primarily directed to a method and product for finishing bowling lanes. That application was abandoned by the applicant in favor of S/N 940,428 (the `428 application) for a bowling lane refinishing material, and S/N 203,617 for a bowling lane refinishing method. The `514 patent essentially incorporates the product and method of the two parent applications, but expands the disclosure beyond the practice of refinishing bowling lanes.
3M manufactures and sells a product called "FloorMinders," which allows advertising, decoration, safety information, and other types of images to be applied directly to a smooth floor surface. FloorMinders is comprised of (1) a base film called Controltac, (2) a graphic image, and (3) a top film called Scotchcal. See Middleton, No. 96-C6781, slip op. at 2, n. 3. Both the top film and the base film consist of a flexible plastic material backed with an adhesive. The top film is clear, and the base film may be either clear or white. FloorMinders is manufactured by sandwiching a customer's logo, message, or other graphic between the adhesive layer of the top film and the nonadhesive layer of the base film. The customer then applies FloorMinders in the desired location by adhering the adhesive surface of the base film to the floor. In its advertising brochures, 3M states that FloorMinders is durable for at least six months.
The only independent claim of the `514 patent at issue in this case is claim 4, which reads as follows:
1. On a floor having a flat top surface and an improved material for finishing the top surface of the floor, the improvement comprising:
at least one elongated sheet including a uniform flexible film of clear plastic material having a thickness between about one mil and about twenty-five mils and
a continuous layer of adhesive material disposed between the top surface of the floor and the flexible film, the adhesive layer releasably adhering the flexible film onto the top surface of the floor. `514 patent, col. 6, line 66 - col. 7, line 10 (emphasis added).
The district court held a Markman hearing to determine the proper scope of claim 4. After hearing arguments from counsel on both sides, the court construed the disputed elements as follows:
Material for finishing: "a material that makes more durable the underlying surface of the floor, and is applied for that purpose."
Uniform flexible film: "the material must be of a uniform thickness, and excludes material in which there are any variations in thickness." See Middleton, Inc. v. Minnesota Mining & Manufacturing Co., No. 96-C6781, slip op. at 1 (E.D. Ill. Feb. 9, 1998) (Markman Ruling and Order).
Following the Markman hearing, 3M moved for summary judgment of noninfringement.
In considering 3M's motion for summary judgment, the district court turned first to the question of literal infringement. The court's analysis centered entirely on its construction of the limitation "material for finishing." Because the court construed "material for finishing" to mean a material that makes a floor "more durable," its initial focus was on whether FloorMinders enhances the durability of the underlying floor. 3M argued that the plastic sheets used in FloorMinders were not designed to enhance the durability of the underlying floor, but rather, were designed to (1) display advertising materials on the floor; (2) protect the advertising materials from wear; (3) make subsequent removal of the FloorMinders product easier; and (4) provide slip resistance. See Middleton, No. 96-C6781, slip op. at 6-7. Furthermore, 3M asserted that FloorMinders is marketed solely as an advertising tool and not as a floor finish or floor protectant. See id.
Middleton argued that, regardless of whether FloorMinders is intended to enhance durability of the underlying floor, the floor is nevertheless protected by the two plastic sheets sandwiching the FloorMinders graphics. See id. at 8. On this point, the court acknowledged that FloorMinders--indeed any floor covering--provides some degree of protection to the underlying floor. However, the court distinguished this element of "protection" from the concept of "durability" by stating that:
[t]o `protect' is typically defined as to cover or shield from exposure or injury. But making something more `durable' involves more than merely covering. `Durable' is defined as `able to exist for a long time without significant deterioration.' Id. at 10 (citations omitted).
Furthermore, the court dismissed, as irrelevant, certain evidence offered by Middleton to show that FloorMinders inherently enhances durability. The court held that, "this evidence does not bear on the issue of how consumers are actually using the FloorMinders product . . . ." Id. at 9.
In sum, the district court construed "material for finishing" to require an element of durability and further construed "durability" to require something more than mere "protection." Having adopted this construction of the term "finishing," the court held that "Middleton has offered no evidence that FloorMinders is actually used for the purpose of floor finishing." Id. at 10. The court therefore concluded that, because FloorMinders does not embody every element of claim 4, it cannot literally infringe claim 4 as a matter of law.
The court next addressed the question of whether FloorMinders could infringe the `514 patent under the doctrine of equivalents, again focusing its attention on the "material for finishing" limitation of claim 4. The court acknowledged evidence submitted by 3M that FloorMinders "does not perform substantially the same function, namely, making a floor more durable, as Middleton's claimed product." Id. at 11-12. Finding that Middleton failed to present evidence to the contrary, the court concluded that FloorMinders does not infringe claim 4 of the `514 patent under the doctrine of equivalents.
Middleton appeals the decision granting summary judgment of noninfringement to 3M. We have jurisdiction over this appeal pursuant to 28 U.S.C. § 1295(a)(1) (1994).
Summary judgment is appropriate only when there is no genuine issue of material fact and the moving party is entitled to judgment as a matter of law. See Fed. R. Civ. P. 56(c). We review a grant of summary judgment de novo. See Spectrum Int'l, Inc. v. Sterilite Corp., 164 F.3d 1372, 1378, 49 USPQ2d 1065, 1068 (Fed. Cir. 1998). In doing so, we must draw all reasonable factual inferences in favor of the non-movant. See Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 255 (1986).
In reviewing a grant of summary judgment of noninfringement, as with any infringement inquiry, we must first determine the correct claim scope as a matter of law. See Renishaw PLC v. Marposs Societá per Azioni, 158 F.3d 1243, 1247-48, 48 USPQ2d 1117, 1120 (Fed. Cir. 1998). We then compare the properly-construed claim to the accused device to determine, as a matter of fact, whether all claim limitations are present in the accused device, either literally or under the doctrine of equivalents. See id.
The first issue we must decide is the meaning of "material for finishing." Since that phrase appears in the preamble of claim 4, we must first ask whether "material for finishing" is a claim limitation at all. Whether a statement of intent in a preamble should limit a claim is an inquiry we undertake on a case-by-case basis. As we have previously stated:
No litmus test can be given with respect to when the introductory words of a claim, the preamble, constitute a statement of purpose for a device or are, in themselves, additional structural limitations of a claim. To say that a preamble is a limitation if it gives `meaning to the claim' may merely state the problem rather than lead one to the answer. The effect preamble language should be given can be resolved only on review of the entirety of the patent to gain an understanding of what the inventors actually invented and intended to encompass by the claim. Corning Glass Works v. Sumitomo Elec. U.S.A., Inc., 868 F.2d 1251, 1257, 9 USPQ2d 1962, 1966 (Fed. Cir. 1989).
Here, the `514 specification makes clear that the disclosed invention is a material and method for applying "a replaceable finish of uniform thickness onto a floor." `514 patent, col. 1, lines 67-68 (emphasis added). Furthermore, during prosecution of the `514 patent and its parents, the applicant amended what subsequently became the preamble of claim 4 several times to avoid prior art. Specifically, the applicant added the term "refinishing," which was later changed to "finishing," and argued to the examiner that "finishing" a bowling lane is patentably distinct from replacing the top of a bowling lane with a thick laminate material. Thus, based on the entirety of the `514 patent and its prosecution history, we conclude that the district court correctly read "material for finishing" as a claim limitation.
Having determined that "material for finishing" is a claim limitation, we must now decide what that limitation means. We begin, as we must, with the language of the claim itself. Terms in the claim are to be given their ordinary and accustomed meaning, within the context of the claim, unless a different meaning is clearly set forth in the written description or the prosecution history. See Johnson Worldwide Assoc., Inc. v. Zebco Corp., 175 F.3d 985, 989, 50 USPQ2d 1607, 1610 (Fed. Cir. 1999); Renishaw, 158 F.3d at 1249, 48 USPQ2d at 1121.
The text of claim 4 leaves little ambiguity as to the meaning of "material"--namely, at least one elongated sheet of a uniform flexible film of clear plastic having a thickness between about one and about twenty-five mils. What remains in dispute is the precise meaning of the phrase "for finishing." In the context of claim 4, "finishing" clearly refers to providing a clear, uniform layer on the top surface of a floor. Significantly, there is no indication in claim 4 as to what level of durability, if any, the "finish" layer must have. Thus, claim 4 implies a broad meaning for the term "finishing," which is consistent with the dictionary definition of "finish." See, e.g., Webster's Ninth New Collegiate Dictionary 464 (1984) (defining "finish" as "the final treatment or coating of a surface," but not identifying any specific properties).
The district court construed "material for finishing" to mean "a material that makes more durable the underlying surface of the floor." We have held that, absent a clear indication in the specification to the contrary, it is improper for a court to add a narrowing characteristic to an otherwise general term that stands unmodified in a claim. See Bell Communications Research, Inc. v. Vitalink Communications Corp., 55 F.3d 615, 621-22, 34 USPQ2d 1816, 1821 (Fed. Cir. 1995). Thus, we now look to the specification of the `514 patent to determine whether the applicant gave a meaning to "finishing" that would require an element of durability to be read into claim 4. See Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582, 39 USPQ2d 1573, 1577 (Fed. Cir. 1996) ("[I]t is always necessary to review the specification to determine whether the inventor has used any terms in a manner inconsistent with their ordinary meaning.").
The specification of the '514 patent contains numerous instances of the words "finish" and "finishing." Most refer to the material of the invention itself; e.g., "the flexible sheet finishing material of the present invention." `514 patent, col. 3, lines 56-57 (emphasis added). However, the applicant also used "finish" or "finishing" to refer to various other materials. For instance, the applicant noted that wooden playing floors "are finished with clear varnish or urethane applied in liquid form." Id., col. 1, lines 22-23 (emphasis added). Also, the applicant explained that, to facilitate sliding movement on bowling lanes, "a very light oil finish" could be applied to the surface. Id., col. 3, line 43 (emphasis added). Finally, the applicant described the use of his invention on "floors of wood, terrazzo, marble, or other smooth finish material." Id., col. 4, line 40-41 (emphasis added). In sum, the applicant's use of the words "finish" and "finishing" are consistent with the ordinary meaning of those terms--namely, a general reference to the top coat, layer or surface on a floor, whether it be varnish, oil, marble, or terrazzo.
3M argues that the '514 specification touts improved durability from the outset and that "material for finishing" must therefore be construed to mean a material that enhances durability. We disagree. Although the specification describes the invention as providing both durability and wear resistance, this does not necessarily mean that durability must be read into claim 4 as a limitation.
The '514 specification recites several objects of the disclosed invention. Some of these pertain to improved durability, but others contain no reference to durability whatsoever. See `514 patent, col. 1, line 62 - col. 2, line 12. The specification alternates between touting the improved durability of the invention and other characteristics that do not involve durability (e.g., simplicity of application, uniformity of thickness, etc.). Thus, there is nothing in the specification that requires "durable" to be read into claim 4 as a modifier of "finishing." See Renishaw, 158 F.3d at 1249, 48 USPQ2d at 1121 ("Where a specification does not require a limitation, that limitation should not be read from the specification into the claims." (citations omitted)).
In addition to considering the language of the claim and the specification, we may also look to the prosecution history of the patent, where relevant, to determine the proper meaning of claim limitations. See Vitronics, 90 F.3d at 1582-83, 39 USPQ2d at 1577. 3M argues that the prosecution history of the `514 patent and its parent applications sheds light on the meaning of "material for finishing."
During prosecution of the `428 application (one of the parents of the `514 patent), the applicant was forced to overcome U.S. Patent No. 4,221,620, issued to Milne. The Milne patent discloses the use of 1/8-inch thick flexible panels to "refinish" a bowling lane. The applicant sought to distinguish his invention from that of Milne on the basis that the present invention utilizes a finish film, rather than a 1/8-inch thick panel. To that end, the applicant explained to the examiner, in an Amendment After Final Rejection, dated July 6, 1988, that his invention "essentially duplicates the characteristics of a conventional liquid varnish." 3M asserts that this argument was made in an attempt to distinguish the claimed invention from the prior art on the basis of enhanced durability. According to 3M, the prosecution history requires that "durability" be read into the claim as a limitation. We disagree.
In making this statement, the applicant was clearly not referring to durability as a distinguishing characteristic. Indeed, the 1/8-inch think panels taught by Milne are themselves quite durable and, thus, durability would not have been a distinguishing characteristic of the claimed invention. Instead, in equating his invention with varnish, the applicant was apparently referring to varnish's characteristic of providing a protective coating without transforming the physical and aesthetic properties of the underlying floor. See Amendment After Final Rejection at 6 ("Being only a finish film, [the claimed invention] does not change the physical characteristics of the wood floor . . . . By contrast, the one-eighth inch thick floor covering materials described by MILNE can modify the physical characteristics, such as resilience and hardness, of a wood bowling lane."). It was this characteristic--preserving the physical attributes of the underlying floor--that successfully distinguished the applicant's invention from that of Milne.
Having reviewed the language of claim 4, the specification of the `514 patent, and the relevant prosecution history, we conclude that the district court erred in reading "material for finishing" to require an element of durability. We recognize, as did the district court, that some degree of protection will be afforded by any type of floor covering, whether it be varnish, plastic, or marble. Middleton's claimed product provides some degree of protection, which varies depending on the thickness of the sheet (1 - 25 mils). Likewise, 3M's FloorMinders provides some degree of protection to the underlying floor. However, to the extent that the court drew a distinction between FloorMinders and the claimed invention on the basis of "durability," we must disagree. Durability is simply not a limitation of claim 4.
The district court interpreted the limitation "uniform flexible film" to mean that, "the material must be of a uniform thickness, and excludes material in which there are any variations in thickness." Middleton, No. 96-C6781, slip op. at 1 (Markman Ruling and Order). Ultimately, the court's infringement analysis did not turn on this limitation because the court found that 3M's FloorMinders product was not a "material for finishing," either literally or under the doctrine of equivalents.
We understand the district court's interpretation to mean that the film must have the same thickness throughout, except that normal manufacturing tolerances are allowed. Thus, while the film cannot have a thickness of 1 mil at one location and 25 mil at another, it may have variations in thickness due solely to the practical realities of the film manufacturing process. We note that at oral argument, the parties did not appear to dispute this reading of the district court's claim construction.
The district court erred in construing "material for finishing" to mean "a material that makes more durable the underlying surface of the floor." In the context of claim 4, "finishing" is a broad term that does not require any particular degree of protection, durability, or longevity. Because the district court granted summary judgment based solely on this erroneous claim construction, we vacate that ruling and remand the case for further proceedings not inconsistent with this decision.
© 1999 VersusLaw Inc.