A contrast photoelectric sensor, also known as a contrast sensor or contrast scanner, is a type of optical sensor used to detect and distinguish contrasting colors or patterns on a surface. These sensors are designed to detect variations in light reflectivity, allowing them to identify objects based on differences in color, brightness, or surface texture. Contrast photoelectric sensors are commonly used in industrial automation applications for tasks such as object detection, part identification, web guiding, print mark detection, and quality control.