Electricity + Control June 2018

optoNCDT 1320/1420 laser sensors are distinctive in their unique conception and de-sign.

PLANT MAINTENANCE + TEST + MEASUREMENT

Laser-based optical displacement sensors measure from a large distance to the target using a very small spot which enables measurements on the smallest of parts.

The so-called 'coplanarity' indicates that all the pins are arranged in line with each other and is therefore considered a critical factor that requires inspection using high precision measurement technology. The component is guided over a trian- gulation displacement sensor which comprises a laser beam that scans the pins. After calculation of the distance values, the sensor arrives at a de- cision regarding whether or not the component should be placed or removed. Requirements of the measurement technology are enormous; not only because the parts are ex- tremely small, but also primarily due to rapid shifts from shiny to matt surfaces. While the pins are composed of shiny metal, the circuit board pre- sents a matt surface. Therefore, the receiver ele- ment in the sensor is alternately exposed to strong and then weak reflections at frequent intervals – a task optoNCDT 1420 laser sensors are optimised to perform. The Auto Target Compensation (ATC) feature provides fast control of different reflections and enables a smooth signal frequency of the dis- tance signal. These laser sensors, set new standards in laser triangulation in terms of functionality and design, and have recently been awarded the Red Dot Award Industrial Design. The laser sensors stand out for their combination of various characteristics. The extremely small laser spot size, which is focused through an optical system to a very small diameter, enables the measurement of extremely fine details. Their compact design – without external controller

– enables installation within restricted spaces. Even the integrated evaluation electronics are space-sav- ing and simplify cabling. Laser line triangulation Besides the inspection of one-dimensional quan- tities, there is also a demand for multi-dimension- al quality control in industrial production. Laser profile scanners are increasingly used for profile and contour measurement applications. Their op- erating principle is based on the laser triangulation technique for two-dimensional profile detection. They detect, measure and evaluate profiles on dif- ferent object surfaces. By using special lenses, a laser beam is en- larged to form a static laser line instead of a point and is projected onto the target surface. An optical system projects the diffusely reflected light of this laser line onto a highly sensitive sensor matrix. In addition to distance information (z-axis), the con- troller also uses camera images to calculate the position along the laser line (x-axis). These meas- ured values are then output in a two-dimensional coordinate system that is fixed with respect to the sensor. In the case of moving objects or a travers- ing sensor, it is possible to obtain 3D measure- ment values. Laser scanners are equipped with an integrated, highly sensitive receiving matrix that enables measurements to be conducted on almost all industrial materials, largely independent of the surface reflection. The inspection of adhesive beading in smart-

The optoNCDT 1320/1420 laser point sensors measure smallest details, for example when inspecting the coplanarity of IC pins in pick-and-place machines.

Production control of smartphones, laptops and tablets using laser line triangulation.

Electricity + Control

JUNE 2018

27