| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve highly accurate position detection by reducing the error component of a detection waveform. <P>SOLUTION: This optical encoder is characterized such that transmittance distribution or reflectance distribution set in the scale track of a displacement scale has a first modulation cycle and a second modulation cycle with respect to a scale displacement direction, and that a light reception element array is arrayed so as to detect a first signal group including a two-phase signal in which a relative phase in the first modulation cycle is inverted and a second signal group including a two-phase signal in which a relative phase in the second modulation cycle is inverted, and that first positional information in the first modulation cycle is detected from the first signal group while second positional information in the second modulation cycle is detected from the second signal group, and that the second modulation cycle is the odd-numbered multiple of the first modulation cycle. <P>COPYRIGHT: (C)2012,JPO&INPIT |
