Abstract: A displacement sensing device includes a sensor of magnetoresistance elements located opposite to a magnetic scale, and is adapted to measure a relative amount of movement between the magnetic scale and the sensor through the use of a variation in a resistive value of the magnetoresistance elements due to the effect of a magnetic pattern on the magnetic scale. The sensor includes magnetoresistance element sections comprised of a first pair of magnetoresistance elements and a second pair of magnetoresistance elements of a pitch different from that of the first pair of magnetoresistance elements. The magnetoresistance element sections are selectively used in accordance with the pitch of the magnetic pattern on the magnetic scale.

Abstract: A multi-gap head apparatus employed in a measuring system using a magnetic scale. First and second thin plates, making up core members, are stamped out with a selected width near the center portion of alternately stacked first rolled plates and second rolled plates made of a highly permeable material and a non-magnetic material, respectively. A compensator plate is interposed between the core members in order to compensate for output distortion due to a thickness error of the first and second thin plates.

Abstract: A measuring system using a magnetic scale is disclosed, which can be readily adjusted when mounting it on a machine tool or the like. A magnetic scale support supporting a magnetic scale bar is secured to a machine tool body. A magnetic head support supporting a magnetic head is secured to a movable member of the machine tool body. An adjusting member secured to the magnetic scale support has a projection, while a cap secured to the magnetic scale support has a recess extending parallel to the magnetic scale bar. The mounting position of the magnetic scale bar in the direction of movement of the movable member is adjusted by moving the movable member, with the projection inserted in the recess.