Afg Industries, Inc. And Asahi Glass Company, Ltd. v. Cardinal Ig Company, Inc. And Andersen Windows, Inc.
Docket: 00-1285
Court: Court of Appeals for the Federal Circuit; February 5, 2001; Federal Appellate Court
AFG Industries, Inc. and Asahi Glass Company, Ltd. appeal a summary judgment of noninfringement granted to Cardinal IG Company, Inc. by the U.S. District Court for the Eastern District of Tennessee. The Federal Circuit, with exclusive jurisdiction under 28 U.S.C. 1295(a)(1), found that the district court erred in its interpretation of the terms 'layer' and 'interlayer' as used in the relevant patent specification. The court determined that the factual record was insufficiently clear to resolve the infringement issues based on the revised claim construction. Consequently, the Federal Circuit vacated the summary judgment and remanded the case for further proceedings.
The case involves competing manufacturers of windows with low-emissivity coatings, which consist of thin, alternating layers of metals applied to glass. These coatings are designed to allow visible light to pass while reflecting radiant heat, thus improving energy efficiency in homes. Prior to 1987, the use of a single layer of silver for such coatings had been found inadequate due to issues with reflectivity and visibility. The patent in question, U.S. Patent No. 4,859,532, filed by Takuji Oyama and others, describes a coating that employs multiple thin layers of silver interspersed with metal oxides, enhancing the reflective properties of the silver without compromising transparency to visible light.
The diagram referenced illustrates the claimed coating from Cardinal's brief. Oyama's patent application describes 'interlayers' that can be placed between silver and metal oxide layers to enhance durability and adhesivity without significantly altering the optical properties of these layers. The application includes a specification stating that interlayers can be employed at various interfaces, ensuring they do not affect optical properties. Oyama provided eight examples of low-emissivity coatings, none of which mentioned interlayers. The initial application had five claims, with claim 4 allowed as claim 1 of the '532 patent, detailing a coating made of five alternating layers of zinc oxide (ZnO) and silver (Ag), but omitting any reference to interlayers.
Oyama canceled the other claims after they were rejected by the PTO examiner due to prior art, while claim 1 specifically includes multiple metallic layers without detailing the use of zinc oxide. AFG and Asahi jointly own the '532 patent. In contrast, Cardinal's low-emissivity coatings have layers of zinc oxide and silver, with some products featuring multiple sequential zinc oxide deposits and thin titanium dioxide "barrier" layers. Cardinal's process involves sputtering silver onto zinc oxide in an argon atmosphere, followed by a titanium deposit that oxidizes into titanium dioxide to prevent silver oxidation. AFG contends that Cardinal's barrier layers function similarly to the interlayers in the patent and asserts that claim 1 encompasses Cardinal's products, including those with 'top coats.'
On May 23, 1996, AFG initiated a patent infringement lawsuit against Cardinal and Andersen Windows, Inc. in the Eastern District of Tennessee. Cardinal and Andersen filed a counterclaim for a declaratory judgment asserting the invalidity of the '532 patent. The district court subsequently severed and stayed the proceedings against Andersen. Markman hearings, conducted on January 13-14, 1998, aimed to clarify disputed claim terms of the '532 patent and address summary judgment motions. On April 7, 1998, the court granted Cardinal's motion for summary judgment of noninfringement without explicitly construing the claim terms and dismissed the counterclaim as moot. AFG filed a notice of appeal on May 7, 1998. On January 5, 1999, the appellate court vacated the district court's decision and remanded the case for explicit claim construction. The district court ordered further briefing on claim construction on April 9, 1999, and on February 25, 2000, issued a memorandum opinion construing 'layer' and 'interlayer,' again granting summary judgment of noninfringement to Cardinal.
The standard of review for summary judgment is de novo, independently evaluating the evidence to identify any genuine material fact issues. Claim interpretation is also reviewed de novo. Patent infringement analysis involves determining the meaning and scope of the claims and comparing them with the accused device.
Cardinal contended that AFG's patent claim pertains solely to coatings with five metallic layers, rejecting coverage for coatings with additional interlayers. Cardinal interpreted the phrase 'composed of' in claim 1 of the '532 patent as a closed transition phrase, thus limiting the claim to exactly five layers of zinc oxide and silver. Cardinal's own coatings included titanium dioxide in addition to the specified layers, leading to its argument that they could not infringe AFG's claim. The court noted that transition phrases like 'composed of' are critical in determining claim scope, distinguishing between open phrases (which allow for additional elements) and closed phrases (which exclude unrecited elements).
The term "composed of" is interpreted as synonymous with "consisting of," but may have a broader meaning in patent law under certain circumstances. The Manual of Patent Examining Procedure (MPEP) indicates that "composed of" should be understood in the context of the specification to determine whether claim language is open or closed. Although the authors of the MPEP are not afforded deference in defining claim terms, the interpretation here aligns "composed of" with "consisting essentially of," suggesting it excludes ingredients that materially affect the claimed composition's basic characteristics while allowing unlisted ingredients that do not have a significant impact.
In this case, the invention relates to a coating made of various layers, where interlayers, while crucial for manufacturing, are not significant to the end product's claimed characteristics. The patent specifies that these interlayers, though optically insignificant, serve to protect the primary layers and do not substantially alter optical properties. Evidence presented during the Markman hearing indicates that interlayers, or barrier layers, are commonly used in low-emissivity coatings containing silver, crucial for production but not essential to the final product. Testimony from industry expert Roger O'Shaughnessy confirmed that barrier layers are vital during the manufacturing process, without which the product would be defective and unusable, even if they are not explicitly referenced in documentation.
A barrier layer is inherently included in the layered coating structures described by Cardinal personnel, even if not explicitly mentioned. O'Shaughnessy noted a common practice of omitting barrier layers in descriptions, as they are assumed to be present and their inclusion complicates communication. During the Markman hearing, a Cardinal document identified a coating as having five primary layers, neglecting to mention the multiple barrier layers that exist. The significance of interlayers, or barrier layers, is primarily related to the manufacturing process, and their presence may not materially affect the final product's characteristics. The determination of their materiality is a factual question, referencing a precedent where the impact of a component on product characteristics was assessed by a jury. The case raises the need to clearly define 'layer' versus 'interlayer,' especially given that Cardinal's products include titanium deposits alongside silver and zinc oxide layers. This distinction is crucial for determining potential patent infringement.
The trial court sought to define the terms 'layer' and 'interlayer' based on their ordinary meanings according to Webster's Third New International Dictionary, identifying 'layer' as "one thickness, course, or fold laid or lying over another" and 'interlayer' as "a layer placed between other layers." However, the court indicated that these definitions were merely a preliminary step and didn't finalize its claim construction. The court also referenced caution against relying solely on dictionary definitions, citing concerns that such definitions could lead to absurd interpretations. The court failed to provide an explicit alternative construction for these terms, which is crucial for jury instructions and appellate review.
Furthermore, the use of general dictionaries to define technical terms is discouraged, as these definitions often lack the specificity needed in a technological context. The trial court's adopted definitions blurred the distinction between 'layer' and 'interlayer' as described in the patent, where 'interlayers' have unique physical attributes that do not significantly affect optical properties, contrasting with the dictionary's broader interpretation. An effective construction of technical terms should align with the context of their use in the patent, using scientific principles rather than general definitions, especially when the terms have specific meanings in the relevant technical field. The current dictionary definitions undermine the proper interpretation of 'interlayer' by neglecting its minimal optical impact as outlined in the patent's description.
The trial court's dictionary definitions for the terms 'layer' and 'interlayer' were inconsistent with undisputed testimony from the Markman hearing. AFG's witness, Mr. O'Shaughnessy, testified that barrier layers are essential for the product's operation, stating, "We can't run this product without barrier layers." This indicates that a person of ordinary skill recognizes a significant distinction between 'layers' and 'interlayers' or 'barrier layers,' which should be reflected in the claim construction. Although the patent's brief description of 'interlayers' could lead to ambiguity, the testimony clarified that this distinction is material.
This case contrasts with Vitronics Corp. v. Conceptronic, Inc., where expert testimony contradicted the patent specification. In the current instance, O'Shaughnessy’s testimony supports the written description's distinction between 'layer' and 'interlayer.' Referencing Pitney Bowes, the court noted that consulting reliable extrinsic evidence is appropriate to ensure claim construction aligns with technical understandings. The Supreme Court has historically emphasized the importance of scientific testimony in interpreting technical terms in patent claims, affirming that rejecting such testimony would be erroneous.
Extrinsic evidence plays a crucial role in informing a court's claim construction, as demonstrated by the case at hand. The testimony of O'Shaughnessy, which is largely undisputed, provides reliable evidence that individuals skilled in the art differentiate between "layers" and "interlayers." The trial court erred by not recognizing this distinction, as outlined in the written description of the '532 patent, leading to a flawed claim construction. The court disregarded O'Shaughnessy's testimony and other relevant evidence presented during the Markman hearing that further clarified the difference between these terms. Although the patent's specification might have introduced some ambiguity, the court should have adopted a definition that clearly distinguishes between "layers" and "interlayers."
Regarding the definitions proposed by the parties, AFG defines a "layer" as a thickness of material with uniform chemical composition, while Cardinal initially suggested a more restrictive definition that required a layer to be bounded by material of different chemical composition. This latter definition aimed to argue that a prior art patent anticipated the asserted claim by classifying multiple deposits as one layer. However, the '532 patent does not impose such a limitation. The parties agree that a "layer" must exhibit chemical uniformity, but AFG contends that impurities from adjacent layers disqualify a deposit from being considered a layer. The court finds that while a metallic deposit must be substantially uniform, minor incorporations of other materials do not disqualify it from being a layer, thereby adopting the definition that a layer's chemical composition must be "substantially uniform."
The definition of 'layer' must differentiate it from 'interlayers.' The '532 patent specifies that 'interlayers' do not significantly affect optical properties due to their minimal thickness. Consequently, 'layer' is defined as a material thickness of uniform chemical composition, explicitly excluding interlayers. Assessing whether a deposit is optically significant should focus on its thickness and composition rather than potential oxidation effects on adjacent layers. The court refrains from deciding whether multiple sequential applications of a chemical compound without intervening layers constitute a single 'layer,' leaving this to be resolved by the trial court.
Regarding additional disputed claim terms, the parties contest the interpretation of 'comprising,' particularly whether a five-layer coating can include a 'top coat' for durability. AFG asserts that the claim allows for additional elements like a top coat, supported by expert testimony indicating that industry practice includes applying protective layers over coatings. Thus, a protective chemical deposit qualifies as a 'top coat' under claim 1, and the trial court may establish further criteria for distinguishing 'top coat' from 'layer' on remand.
The term 'formed on' is also disputed, with concerns about whether it necessitates direct contact between layers. The court clarifies that the claim and specification do not require each layer to be formed directly on the preceding one, allowing for interlayers, and thus defines 'formed on' as not necessarily implying direct contact.
At least some of Cardinal's accused products have titanium deposits of 50 angstroms or more. The trial court referenced expert testimony indicating that prior art coatings had interlayers of only 5 or 6 angstroms, which were deemed to have negligible impact on optical properties. The court inferred that AFG contended that thicknesses significantly greater than this would be optically significant, leading to the conclusion that the titanium deposits in Cardinal's products qualify as 'layers.'
However, the record does not clearly establish AFG's stance on what constitutes an optically significant thickness. Expert Roy Gordon indicated that while 100 angstroms would be significant, thicknesses around 20 angstroms would not. Additionally, a patent cited by Gordon suggests that thicknesses up to 40 angstroms might also lack significant optical effects. The appellate court found the trial court’s appraisal of AFG's position to be incorrect based on these clarifications.
Gordon’s later declaration noted that a 35 angstrom layer would significantly affect optical properties, but this statement was not previously examined during the summary judgment hearing, raising uncertainty about its relevance and AFG's position on the matter. Consequently, the appellate court expressed discomfort in relying on this statement as a basis for affirming the trial court's noninfringement ruling.
Due to the ambiguities in the evidence and the revised claim construction, the appellate court vacated the trial court’s noninfringement judgment and remanded the case for further proceedings. On remand, the trial court may determine that Cardinal is entitled to summary judgment for noninfringement or invalidity, or both. It is noted that the trial court had not addressed Cardinal's motion for summary judgment of invalidity based on prior art, which must also be resolved on remand. The court may grant summary judgment of noninfringement if it finds no genuine dispute regarding Gordon's assertion about the significant impact of a 35 angstrom titanium dioxide layer.
The titanium deposits in Cardinal’s products are determined to be thick enough to be optically significant. The trial court has the option to proceed based on the existing record or to allow additional evidence in light of the revised claim construction. The term "composed of" is interpreted as "consisting essentially of," allowing claim 1 of the '532 patent to encompass coatings with interlayers or barrier layers, provided their thickness does not significantly affect optical properties. The definitions of "layer" and "interlayer" were incorrectly construed by the trial court, as the distinction in the written description and supporting extrinsic evidence was not maintained. Specifically, "layer" is defined as material of substantially uniform chemical composition, excluding interlayers that do not significantly affect optical properties. The term "comprising" is defined to allow the claim to include coatings with a "top coat" or "overcoat," and "formed on" is clarified to not mean "directly in contact with." Due to the adoption of this new claim construction and the unclear record from the trial court, the judgment is vacated and remanded for further proceedings, with each party bearing its own costs. O'Shaughnessy’s testimony is considered reliable for understanding the terms "layer" and "barrier layer," despite inconsistencies in internal documents regarding the thickness of titanium deposits in Cardinal’s products, which are noted to be either 50 angstroms or 20 angstroms thick based on conflicting evidence.
