376 Prakt. Met. Sonderband 46 (2014) 
The precision optics of InfiniteFocus consists of various lens systems and can be equipped smoot 
with different objectives, allowing measurements with different resolution. With a beam cleara 
splitting mirror, light emerging from a white light source is inserted into the optical path of One c 
the system and focused onto the specimen via the objective. Depending on the the ‘re 
topography of the specimen, the light is reflected into several directions as soon as it hits a radi 
the specimen. If the topography includes diffuse reflective properties. the light is reflected Alicon 
equally strong into each direction. elliptic 
In case of specular reflections, the light is reflected mainly into one direction. All rays resolu 
emerging from the specimen and hitting the objective are bundled in the optics and region 
gathered by a light sensitive sensor behind the beam splitting mirror. Due to the small In ad 
depth of field of the optics only small regions of the object are sharply imaged. To allow a Infinite 
complete detection of the surface with full depth of field, the precision optics is moved detail 
vertically along the optical axis. This means that each region of the object is sharply for th 
focused. A sensor captures a series of 2D datasets during this scanning process. Thereby, visual 
all sensor parameters are optimized at each vertical position according to the reflective 
properties of the surface. After the scanning process, the 2D datasets are evaluated to 
generate 3D information as well as an image with full depth of field. This is achieved by 
analyzing the variation of focus along the vertical axis. Due to the large amount of data 
mechanical restrictions can be eliminated, allowing measurement results with a high 
resolution. Once all height measurements are determined, an image with full depth of field 
is computed. 
To measure those steep flanks, InfiniteFocus uses light coming from different directions. In 
addition, the measurement of the maximum flank angle is not restricted by the numerical 
aperture. This is achieved via add-ons such as optional ring light or polarisation to support 
the measurement of complex geometries. Also, highly polished components and materials 
with varying surface characteristics or reflection patterns are now measurable. This is 
achieved with modulated light, providing optimal illumination throughout the whole 
measurement area. Operators measure glossy, ground, rough, reflective and diffuse 
components. 
The technique of Focus-Variation has been accepted in the draft of a new ISO standard 
25178, which is a recently developed standard for area-based roughness measurements. 
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5. FURTHER APPLICATIONS comp: 
The range of areas where Focus-Variation can be applied is almost unlimited. In tool- and 
mold making, quality assurance with InfiniteFocus is a worldwide standard. Quality 5.2 CI 
assurance and in-production measurement include cutting edge measurement as well as 
full form and roughness measurement of drills, millers, inserts etc. With InfiniteFocus in The « 
both material and process optimization manufacturer maximize turnover also in micro instrul 
manufacturing, automotive industry, medical device development, pharmaceutical industry. meas 
injection molding, aerospace industry, electronics and forensics. conce 
mach 
manu 
5.1 CUTTING EDGE MEASUREMENT Meas 
For both profile- and area-based surface measurement, Focus-Variation is used to verify adher 
dimensional tolerances in the field of cutting edge preparation. Users apply the technology auton 
to traceably and repeatably measure the complex geometries of deburred. ground manu