Industrial sensor that uses light to detect the presence, position, and distance of objects in a non-contact manner. It emits infrared or laser light from the light-emitting section and detects reflected light or light interruption at the light-receiving section to perform part detection, positioning, counting, and quality inspection on manufacturing lines. Available in various detection methods including through-beam, reflective, retro-reflective, and diffuse reflective types, compatible with various materials such as metal, resin, and glass. Used in wide applications including product detection on conveyors, robot arm position control, parts supply management in automatic assembly equipment, and product counting in packaging machinery. Unlike proximity sensors or pressure sensors, it features high-precision non-contact detection, enabling high-speed line compatibility and long service life.