| 摘要 |
PURPOSE:To obtain an encoder having a stable spacing characteristic by a method wherein the stripe length direction of a magnetoresistance (MR) element is made perpendicular substantially to the surface of a magnetic recording medium while the strip width direction thereof is made parallel to the direction of a magnetized pattern array. CONSTITUTION:A magnetic recording medium 1 is formed on the outer peripheral part of a drum 4 fixed to a rotating shaft 3, while an MR element 2 and a terminal 6 are formed on a glass substrate 5 and connected to a drive detector circuit 8 through a lead wire 7. The stripe length direction of the element 2 is made perpendicular substantially to the surface of the recording medium 1, while the stripe width direction thereof is made parallel to a magnetized pattern array of the recording medium 1. Arrows marked on the recording medium 1 represent the degree of intensity of magnetization and are magnetized by means of a ring head. On the occasion, the distribution of the intensity of magnetization shows a triangular shape in one magnetized pattern array, and a phase difference between first and second arrays is 90 deg.. Thus, a change in the resistance of the element 2 occurs in accordance with the intensity of magnetic field leaking from the recording medium 1. An output signal of this change is inputted to the circuit 8, and the position of a motor can be detected from the amplitude of the signal.
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