| 摘要 |
PROBLEM TO BE SOLVED: To materialize speeding up and price reduction of a photoelectric incremental type encoder by performing detection by using a light receiving element array of a long pitch as in the past, even if the grating pitch of a scale becomes narrow. SOLUTION: In this photoelectric incremental type encoder of a three-grating type, a first grating 14 for modulating light from a light source 10, a second grating 22 formed on the scale 20, and a third grating 30 with an interference fringe 24 projected thereonto which is formed by the first and second gratings 14 and 22. The incremental type encoder is equipped with a lens optical system 50 for projecting Moire fringes 32, generated on the third grating 30, onto the light-receiving element array 40. COPYRIGHT: (C)2007,JPO&INPIT
|
