Triangulation distance sensors represent a critical technology in non-contact measurement, offering high precision for various industrial and commercial applications. Unlike simple time-of-flight sensors, triangulation-based systems rely on geometric principles to determine distance with remarkable accuracy. The core mechanism involves projecting a light spot, typically from a laser diode, onto a target surface. A lens then collects the reflected light and focuses it onto a position-sensitive detector, such as a CCD or CMOS array. The key to measurement lies in the triangle formed by the light source, the detected spot position on the sensor, and the target point. As the distance to the target changes, the angle of the reflected light shifts, causing the focused spot to move laterally across the detector. By precisely calculating this displacement using the known baseline distance between the emitter and detector lenses and the fixed angles within the system, the sensor's onboard processor can compute the exact distance to the target. This method provides significant advantages, including micron-level resolution, high-speed response, and excellent performance on a wide range of surface materials and colors. However, performance can be influenced by the target's optical properties; highly reflective or transparent surfaces may require special treatment or sensor calibration. Common industrial uses include precision thickness gauging, wafer inspection, assembly robot guidance, and profile scanning. In consumer electronics, these sensors enable autofocus systems and gesture recognition. Modern advancements integrate smarter algorithms to compensate for surface variations and environmental light, expanding their usability in challenging conditions. When selecting a triangulation sensor, engineers must consider parameters like measuring range, spot size, linearity, and sampling rate to match the specific application needs. Proper installation, avoiding optical interference, and regular maintenance are essential for sustained accuracy. As automation and quality control demands grow, triangulation distance sensors continue to evolve, becoming more compact, robust, and integral to intelligent manufacturing and IoT systems, providing reliable data for process optimization and innovation.