| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a non-contact thickness detector capable of accurately detecting thickness of a work piece, and a grinder equipped with the thickness detector. <P>SOLUTION: A thickness detector is equipped with: detection light irradiation means which includes an illuminant which has a predetermined wavelength region with transparency to a work piece, and a condenser; a condenser lens which condenses reflected light reflected on the upper surface and the lower surface of the work piece irradiated by the detection light irradiation means and held in a chuck table; diffraction gratings which diffract interference of the reflected light condensed by the condenser lens; an image sensor which detects light intensity of the reflected light diffracted by the diffraction gratings in a predetermined wavelength region; and control means for calculating a spectroscopic interference waveform based on a detection signal from the image sensor, and calculating the thickness of the work piece based on difference in optical path length between the optical path length of the reflected light reflected on the upper surface of the work piece and the optical path length of the reflected light reflected on the lower surface of the work piece, in which the detection light irradiation means irradiates the upper surface of the work piece with P polarization light at a predetermined incidence angle. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
