In this paper, we investigate the combination of two gratings for a compact optical displacement encoder. The modulated pitch gratings are considered to obtain the sinusoidal signal as a function of displacement. In addition, the phase grating with the pitch modulation is examined to suppress the contrast change of the encoder signal as a function of the gap between the index and main scales. By these investigations, we find some combinations of gratings to satisfy the above requirements.
|Number of pages
|Proceedings of SPIE - The International Society for Optical Engineering
|Published - 1999
|Proceedings of the 1999 Optical Engineering for Sensing and Nanotechnology (ICOSN '99) - Yokohama, Jpn
Duration: 1999 Jun 16 → 1999 Jun 18