A mask pattern includes a main pattern to be transferred through exposure and an auxiliary pattern that diffracts exposing light and is not transferred through the exposure. The low emissivity panels can also include NiNbTiOx as a barrier layer. When the 2-to-1 selector is controlled to supply the address decoder with a repair address signal, the address comparator is controlled to have a repair signal information holding section, which is installed in the address comparator, hold the repair address decoded by the address decoder. The interferometric system provides the processor with information relating to wear of the optical fiber, and the processor determines wear of the seal, rate of wear and remaining useful life of the seal based on the information relating to wear of the optical fiber.