Laser Profile Scanners: High Precision to the Most Minute Detail

The miniaturization trend is growing more and more - even in machine design and machine building. Therefore, the components to be installed have got to become even smaller. The new laser profile scanners of the scanCONTROL product series are ideally suited to this development. Their compact size coupled with the maximum resolution with the smallest possible laser line allows new dimensions in quality control.

scanCONTROL Laser Scanners

With regards to their accuracy, size and measuring rate, the scanCONTROL laser scanners belong in the group of the world’s highest performing laser profile sensors. Their operating principle is based on the laser triangulation method for 2D profile detection. The sensors detect, measure and assess profiles on varying object surfaces. By employing special lenses, a laser beam is enlarged to create a static laser line instead of a point and is aimed onto the target surface.

An optical system aims the diffusely reflected light of this laser line onto a very sensitive sensor matrix. Besides distance information (z-axis), the integrated controller in the sensors also uses this camera image to estimate the position along the laser line (x-axis). These measured values are then output in a 2D coordinate system that is fixed with respect to the sensor. In the case of a traversing sensor or moving objects, it is thus possible to acquire 3D measurement values.

Micro-Epsilon’s laser profile scanners are available in a variety of classes. The COMPACT sensors are designed to provide calibrated profile data for external profile analysis, for instance, on a PC. They are ideal for dynamic and static measurements. HIGHSPEED class sensors with a profile frequency of up to 4000 Hz offer everything for cutting-edge high speed and 3D applications. The scanCONTROL SMART series delivers plug & play solutions for simple-to-complex measurement operations, eliminating the need for any external PC or controller. The GAP class offers a plug & play solution specifically for gap measurements. The gapCONTROL Setup Software enables the required set up and configuration for various gap types and to store them in the sensor.

The scanCONTROL 29xx-10/BL sets a new standard with regards to profile resolution. Fitted with Micro-Epsilon’s advanced Blue Laser technology, the scanCONTROL 29xx-10/BL laser profile scanner offers an effective measuring range of just 10 mm with a profile resolution of 1280 points. This results in a point distance of just 7.8 µm, which enables the laser profile scanner to offer twice the resolution of earlier laser scanners with a 25 mm measuring range. The blue laser line used can be projected considerably more sharply than the red one. While allowing higher stability, the blue laser light does not penetrate the measurement object because of the shorter wavelength of the blue-violet laser. Red-hot glowing and even organic objects are measured more reliably than the red laser scanners. These special features enable these laser scanners to detect even smallest parts with maximum precision.

The scanCONTROL 29xx-10/BL is used in applications where the maximum precision and resolution are required, such as precision mechanics, electronics, medicine, and in the production of precision parts. For instance, when checking the position of razor blades relative to each other, checking electronic components for positional tolerances, or verifying laser-welded seams for completeness, the new scanCONTROL model exhibits its technical strengths. The total electronics is housed in a compact sensor body, where all the signal processing occurs, which eliminates the requirement for an external controller.

Modern technical devices such as laptops and mobile phones need absolute precision. Thus, reliable quality control involving the monitoring of individual production steps is essential. This operation is realized using the state-of-the-art scanCONTROL 29xx-10/BL laser profile scanner, which is specially designed for measuring very small target objects. The inspection of adhesive beading in smartphone housing is a common application. A specific challenge in this case is the extremely fine contours within the smartphone and very thin, partially semi-transparent adhesive beading. Here, absolute reliability and 100% control of the fullness of the beading, the width and height of the applied adhesive are needed. This also applies to the logos on laptops and tablets: grooves are milled into the aluminum housing, in which the logo elements are glued later.

Production control of smartphones, laptops and tablets.

Production control of smartphones, laptops and tablets.

The latter has to be flush with the housing. Haptics (i.e. touch sensation) is an important factor, as the customer would instantly feel any protruding logo or depression. Using laser line scanners, these depressions are measured so as to establish the planarity as well as the depth. The parts being glued are also measured so as to guarantee a perfect fit.

Especially in medicine, excellence is a vital requirement. The mounting process of insulin pens, for instance, demands 100% reliable control. Improper engagement of these pens can result in incorrect dosage of the volume of insulin, which potentially could cause life-threatening low or high blood sugar levels. In the manufacture of insulin pens, both parts of the pen have to be inspected to confirm whether they are properly engaged. This is a very challenging task for conventional measurement systems. As well as the high cycle rate, the measuring gaps are extremely small and the difference between engaged and not engaged is only 50 µm. This challenging monitoring operation is effectively accomplished using laser profile sensors with a blue laser line. The very high resolution of the scanCONTROL 29xx-10/BL permits the reliable detection of the closed gap.

Pacemakers are needed when the natural pacemakers of the heart do not work efficiently anymore. Pacemakers normalize everyday life for patients and enhance their performance and exercise tolerance. The devices are only as large as a two-euro coin. The weld seams that connect the two halves of the pacemaker housing are much smaller. These seams have miniature pores with dimensions of merely 40 µm. The seams must be checked geometrically at high precision so as to detect any leakages that may sacrifice the functionality of the devices. Elevations of the weld seam could cause micro injuries in extreme cases. In this case, laser profile scanners from Micro-Epsilon are also used.

Inspection of smallest, electronic components using scanCONTROL 29xx-10/BL.

Inspection of smallest, electronic components using scanCONTROL 29xx-10/BL.

Other fields of application in Medical Engineering include the manufacture of needles where the precise tip angle is vital, the gap measurement of implants and prostheses, as well as the measurement of blade angles, and the cutting length of medical blades.

Furthermore, with modern razor blades, precision is an important factor, focusing on realizing optimum results on smooth skin, avoiding irritations and perfect application comfort. Thus, multi-blade razor production needs an ideal angle position of the three or five single blades with respect to the head, as this is important for the final shaving performance.

scanCONTROL 29xx-10/BL for precise measurements of tiny objects.

scanCONTROL 29xx-10/BL for precise measurements of tiny objects.

Moreover, it must be guaranteed that all blade points are correctly aligned and that no blades are protruding. The special challenge of this measurement operation is how small the measurement objects are, which here are the blade points – a small reference surface for angle measurements. Just 1 mm width per blade is visible. The blade point is below 150 µm. A miniature, small surface area has to be measured during production control.


In automated processes, high precision measurement is of great significance. Laser profile sensors can achieve dimensional measurements, capture measuring points much quicker and measurement data is normally available in real time in digital format. This facilitates the automatic correction, control and quality assurance of live processes.

This information has been sourced, reviewed and adapted from materials provided by Micro Epsilon.

For more information on this source, please visit Micro Epsilon.

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