Digital fringe projection

Fringe patterns consisting of parallel stripes are projected onto the object surface, and their perspective deformation is recorded by a camera. The high number of points acquired simultaneously delivers even the smallest details. The measurement not only delivers extremely good height resolution (e.g. down to 50 times smaller than the fringe width) it is also very fast.
Some advantage are:

  • Area based measurement
  • Measurement times from Extreme height resolution
  • Large vertical measurement range within a single measurement
  • Very low operational costs

Precise grey-scale intensity values are of the utmost importance for this type of phase measurement. To obtain these very high levels of precision in the illumination field LMI uses the unique advantage of a digital micro mirror display technology (DLP) from Texas Instruments, exclusively utilized for fringe projection by LMI.

The microscopic mirror suspensions (picture to the left, marked in red) have virtually unlimited life expectancy due to the effect of hyper elasticity, this together with high temperature stability and extremely low drift provides for continuously accurate measurements.

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