TAKEX Sensor, SEEKA Sensor ‘s background suppression sensors illuminate the detection object and the reflection is detected by the difference in light angles to and from the sensor. Unlike diffusion reflective sensors, this group of sensors incorporates circuitry and optics to reduce or eliminate variations in received signal strength caused by: material on the lens, quality and variations in the material or color of the object being detected, etc. This feature provides for a uniform output when these conditions are a concern.