Opinion ID: 772056
Heading Depth: 3
Heading Rank: 2

Heading: this court's construction of layer and interlayer

Text: 51 The parties' proposed definitions for the term layer are not much in disagreement. AFG asserts that a layer is a thickness of a material of uniform chemical composition. Although Cardinal now seeks a simple affirmance of the trial court's construction, it originally proposed that a layer should be a thickness of a material of uniform chemical composition bounded by a material of a different chemical composition. Under Cardinal's original approach, two adjacent deposits of the same material would consist of only one layer. 52 Cardinal appears to have advocated applying this further limitation so that a prior art patent, U.S. Patent No. 4,943,484 to Goodman (that appears to disclose sequential deposits of zinc oxide/silver/zinc oxide/zinc oxide/silver/zinc oxide), would constitute a five layer coating and thus anticipate the asserted claim. However, the specification of the '532 patent nowhere limits the term layer to a deposit bounded by a material of a different chemical composition. We thus decline to include such a limitation in our construction of the term layer. 53 The parties both suggest that to constitute a layer, a deposit must have a uniform chemical composition. AFG suggests that because the titanium deposits in Cardinal's products appear to have incorporated silver and zinc oxide molecules from adjacent layers, that the titanium deposit cannot itself constitute a layer. However, focusing on the chemical uniformity of a deposit, rather than its optical properties, constitutes a departure from the disclosures and teachings of the patent. Nowhere does the patent refer to chemical uniformity as a characteristic of a layer or interlayer. While we do not doubt that a metallic deposit must be substantially uniform to constitute a layer, we do not think that the incorporation of trace amounts of silver or zinc oxide into a titanium deposit would disqualify that deposit from constituting a layer. Accordingly, we hold that the chemical composition of a layer must only be substantially uniform, rather than uniform. 54 The definition of layer, as discussed above, must also distinguish between layers and interlayers. The written description of the '532 patent distinguishes between these two terms by stating that interlayers have a thickness not to substantially affect the optical properties. Consistent with the specification, we conclude that layer should be interpreted as: a thickness of material of substantially uniform chemical composition, but excluding interlayers having a thickness not to substantially affect the optical properties of the coating. When determining whether a deposit is optically significant, the focus should be on whether the thickness and composition of the material itself is optically significant, rather than whether the absence of that material would lead to oxidation and discoloration of adjacent layers. Moreover, we make no determination as to whether a chemical compound that has been deposited in multiple separate, sequential applications, without intervening layers or interlayers, constitutes a single layer. This is a matter for the trial court to resolve in a manner consistent with our claim construction. 55 3. How should the remaining disputed claim terms be construed? 56 The parties contest the meaning of several other terms found in claim 1 of the '532 patent. Following is the court's resolution of these remaining terms. 57 a. comprising 58 The parties dispute whether the asserted claim reads on a five-layer coating that is covered by an additional top coat or overcoat, which may be a thin deposit used to improve the durability of the coating. AFG notes that the claim recites a transparent laminated product comprising a substrate and a coating, and argues that this claim is open to the presence of additional elements, such as a top coat. 59 Although neither party has offered a definition of a top coat, we note that AFG's expert, Professor Roy Gordon, testified during the Markman hearing as to how one skilled in the art would understand the top coats. He stated: You can put additional layers on top of the five layered transparent coating for the purpose of protecting them, and that's commonly done in the industry. Similarly, Robert Bond, the Operations Manager at one of Cardinal's facilities, testified for Cardinal that he found that applying a thin layer of zinc oxide on top of their coatings rendered them remarkably hard and chemically resistant to acidic washes. In light of the testimony offered by both parties on this subject, we think that a chemical deposit on top of a coating that is primarily used to protect the stack would constitute a top coat, and that a product with such a top coat would fall within the scope of claim 1 of the '532 patent. Because the parties did not focus on this issue in their briefing, and the trial court did not directly address it, the trial court may choose to set forth additional criteria on remand for determining what constitutes a top coat, as distinguished from a layer. 60 b. formed on 61 The parties dispute whether the claim language requires that each successive layer be formed on the prior layer in such a way that nothing is interposed between each layer. As described above, however, the court has determined that the claim language and the specification permit the presence of interlayers between layers. Notably, the claim does not state that each layer is formed directly on the preceding layer. Accordingly, we determine that formed on does not mean directly in contact with.