Contrast readers detect the finest differences

Contrast readers are versatile and are therefore suitable for a whole range of applications, e.g. as pulse generators for counting devices, for non-contact position detection, for position and orientation detection of fast-moving objects, for high-precision detection of object edges, for position control of print or color marks, for discrimination of brightness deviations on objects, or for intensity control of so-called self-illuminators, such as LEDs, displays, etc.


Contrast readers are high-resolution optical sensors that distinguish objects or marks according to the reflectivity or contrast of their surface. For the devices to function smoothly, it is crucial that there is a sufficient difference with respect to the environment or the marking substrate, whether this tends to be bright (higher reflectance) or dark (lower reflectance).


This white paper describes how ipf electronic‘s contrast scanners work and provides an overview of both the compact devices, which operate primarily with visible laser light, and the high-end solutions for connecting fiber optics. Finally, an application example gives an impression of the potential of these devices in industrial practice.