| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively utilize reflected light by increasing a light receiving area. <P>SOLUTION: Light receiving element groups 140L, 140R for incremental patterns are disposed separately in the circumferential direction of a rotating disk 110 so as to interpose a light source 130 between them, and first and second light receiving element groups 150D, 150U for absolute patterns are disposed on both outer and inner sides of the light source 130 in the radial direction of the rotating disk 110. Thus, while first and second light receiving elements 151, 152 for absolute patterns are continuously disposed, the light receiving element groups 140L, 140R for incremental patterns and the light receiving element groups 150D, 150U for absolute patterns can be disposed so as to surround the light source 130 from four directions. <P>COPYRIGHT: (C)2012,JPO&INPIT |
