Classification of optical microscopes used in quality control, inspection, and research and development in manufacturing. These are magnification observation devices utilizing visible light, used for metal structure observation, surface defect inspection, dimensional measurement, and foreign matter analysis. Includes main equipment such as biological microscopes, metallurgical microscopes, toolmaker's microscopes, polarizing microscopes, and phase contrast microscopes, as well as accessories including objective lenses, eyepieces, illumination systems, stages, and measurement attachments. Unlike electron microscopes or digital microscopes, this covers conventional microscopes that perform magnified observation through optical lens systems, specialized for material evaluation, quality inspection, and defect analysis in manufacturing environments.