A photoelectric sensor is a device that detects objects using a beam of light, usually infrared or visible. It consists of a light emitter and a receiver that work together to sense when the light beam is interrupted or reflected. There are three main types of photoelectric sensors, and each works in a slightly different way depending on the application.
The first type is the through-beam photoelectric sensor, where the emitter and receiver are placed opposite each other. The sensor detects an object when it blocks the light beam. This type provides the longest sensing distance and the highest reliability, making it ideal for applications like detecting objects on conveyors or monitoring large packages. The second type is the retro-reflective photoelectric sensor, where the emitter and receiver are housed in the same unit, and a reflector is placed opposite. The sensor detects an object when it interrupts the reflected light beam. It offers good range and easy alignment, perfect for general-purpose detection tasks. The third type is the diffuse-reflective photoelectric sensor, which also has the emitter and receiver in one housing but detects objects based on the light reflected directly from the object’s surface. It is commonly used for short-range detection and in applications like part presence or color sensing.
Omron Photo Sensor products include all three of these types, designed for dependable performance in industrial automation. Omron’s through-beam, retro-reflective, and diffuse-reflective sensors are widely used in packaging, assembly, and material handling systems because they offer stable detection, long life, and easy installation. Each type serves a specific need — through-beam for long distance, retro-reflective for easy setup, and diffuse-reflective for flexible short-range detection.