Magnetic encoder

Abstract

Abstract PURPOSE: To obtain a higher resolving power by setting the angle between the longitudinal direction of the stripes of a magneto-resistance effect element and the surface of a magnetic recording medium to a specific range. CONSTITUTION: The figure reveals that the output decreases until the output attains a noise level with inclination in the stripes of the magneto-resistance effect element 5 if the angle α between the longitudinal direction of the stripes and the surface of the magnetic recording medium 3 is so set as to be in the range from tan -1 (2(l+g)/p)° 90° where the pitch of the magnetization pattern of the medium 3 is designated as (p), the unit stripe length of the element 5 as l and the nearest distance between the medium 3 and the element 5 as (g). The stripes are so provided that the transverse direction thereof is in parallel with the direction where the magnetization patterns are arranged and, therefore, the direction where the element receives the influence of a diamagnetic field is in the transverse direction of the stripes and since the pitch (p) can be decreased regardless of the stripe width, the higher resolving power is obtainable. Since the intensity (shown by arrows in the figure) of the magnetization of the medium 3 changes within one pitch (p), the change in the resistance of the element 5 arises according to the intensity of the magnetic field leaking from the medium 3. This encoder is usable as a position detector. COPYRIGHT: (C)1989,JPO&Japio

Inventors

• 👤 Mitsuaki Ikeda
• 👤 Kenji Hara

Bibliographic Details