Eyeglass Glass with Composite Antireflection Layer

The patent divides the single thick gold layer into multiple thinner layers (first precious metal layer, second precious metal layer) separated by a dielectric layer. This segmentation allows each layer to be optimized for specific functions: the first layer provides metallic appearance, the dielectric layer controls reflection through its refractive index, and the second layer enhances the overall effect. The total gold thickness is reduced while maintaining aesthetic quality.

The patent creates a composite structure combining precious metal layers with a dielectric layer having specific refractive index properties. This composite approach allows the dielectric layer to act as an optical intermediary that reduces reflection through impedance matching, while the thin precious metal layers provide the desired metallic appearance. The combination achieves both aesthetic and optical performance that neither material could achieve alone.

The patent segments the precious metal application into multiple thin layers rather than one thick layer. The first precious metal layer is applied to the substrate, followed by a dielectric layer, then a second precious metal layer. This segmentation allows the total precious metal thickness to be reduced (improving light transmission and reducing cost) while the dielectric layer maintains the optical integrity and metallic appearance through its refractive index properties.

The dielectric layer acts as an intermediary between the two precious metal layers. It has a refractive index specifically chosen to reduce reflection and enhance the metallic appearance. This intermediary layer allows thin precious metal layers to achieve the visual effect of a thick layer while actually using less precious metal, thus resolving the contradiction between appearance quality and material quantity.

The patent applies segmentation by dividing the coating into three distinct layers deposited in sequence: first precious metal layer, dielectric layer, and second precious metal layer. Each layer is deposited using standard vacuum deposition techniques, making the process manufacturable. The segmentation enables control over reflection and appearance that a single layer cannot achieve, while remaining compatible with existing manufacturing capabilities.

The patent changes the optical parameters of the structure by introducing a dielectric layer with a specific refractive index (between 1.3 and 2.6) and controlling the thickness of each layer. These parameter changes optimize the optical performance for metallic appearance and reduced reflection. The thicknesses are specifically controlled: first precious metal layer (5-20 nm), dielectric layer (50-200 nm), second precious metal layer (5-20 nm), creating a structure that balances manufacturing feasibility with optical performance.