CAO Lighting sued Feit Electric for patent infringement regarding a semiconductor light source. The district court granted summary judgment for Feit Electric, based on a claim construction requiring the "first reflective layer" to be an epitaxial layer and different from the substrate. The Federal Circuit reversed, finding the district court's claim construction erroneous because it improperly limited the definition of "reflective layer". The appellate court vacated the summary judgment and remanded the case for further proceedings consistent with its opinion, clarifying that the "first reflective layer" need not be an epitaxial layer distinct from the substrate. The appellate court awarded costs to CAO Lighting.