Optical 3D scanners are devices that irradiate laser or LED light onto objects and analyze reflected light to measure and digitize three-dimensional shapes with high precision in a non-contact manner. In manufacturing, they are utilized for dimensional inspection of machined parts, mold shape measurement, assembly quality control, and reverse engineering applications. Various models are available according to usage including handheld, stationary, and robot-mounted types, achieving measurement accuracy from tens of micrometers to several micrometers. They support CAD data comparison inspection, 3D printer data creation, and shape change tracking in process management, enabling measurement of complex shapes and soft materials that are difficult with conventional contact-type measuring instruments. They contribute to quality assurance and productivity improvement in precision manufacturing sites for automotive parts, aircraft components, medical devices, and electronic components.