| 摘要 |
<p>A first pattern which repeats change in the longitudinal direction with a predetermined pitch and a second pattern which changes in the longitudinal direction with a pitch which is different at least from that of the first pattern; both formed of a predetermined material, are disposed on a surface of a rod section. A detection head section is provided in proximity to the rod section, responds individually to the first pattern and the second pattern, changes its relation of correspondence to the respective patterns in accordance with it linear position with respect to the rod section and produces output signals in accordance with the relation of correspondence to the respective patterns. In accordance with the output signals corresponding to the respective patterns, first and secondd absolute position data of different ranges whose one cycle is constituted of one pitch of the respective patterns can be obtained. By combining these absolute position data, linear position of the detection head section with respect to the rod section can be specified in an absolute value. By disposing the first and second patterns in a mixed state on a single rod section, the construction of the device can be simplified.</p> |
