| 摘要 |
A position measuring instrument for measuring the relative position of two objects movable relative to one another. The position measuring instrument comprises a periodic measurement scale division having a period t and a scanner unit, wherein the scanner unit and the periodic measurement scale division move relative to one another in a measuring direction. In addition, the scanner unit comprises four groups (A-D) each comprising at least four magnetoresistive elements (An-Dn) (n=1, 2, 3, 4, . . .), which are interconnected in the form of a series-parallel circuit to form a half bridge circuit having an upper branch and a lower branch. The upper branch comprises a magnetoresistive element from each group (A-D) and the lower branch comprises a corresponding magnetoresistive element from each group (A-D). Furthermore, the magnetoresistive elements of the upper branch are offset from the corresponding magnetoresistive elements of the lower branch by t/2. The position measurement instrument further comprises an evaluation device to form position measurement values from position-dependent output signals generated by the magnetoresistive elements in response to relative movement between the periodic measurement scale division and the scanner unit.
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