Most optical stylus sensors composed of laser diode as a light source and objective lens are troubled with signal noise when being traversed over machined engineering surfaces. Its main causes are ...irregularity and asymmetry of reflected light intensity distribution due to speckle noise inevitably included in the reflected light and geometrical inclination of sample surface. The optical compensation method of reducing the speckle noise was developed in the previous report. This paper describes the effect of sample surface inclination on the detected displacement signal and reveals that such component can be corrected by using the same optical system as the speckle noise reduction system. Experimental verification of the total error compensation propriety is also presented.
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