Magnetic encoder

摘要

To provide a magnetic encoder that is stable relative to an outside force and has only small variation of a gap between a magnetic sensor and a magnetic medium. The magnetic encoder includes a magnetic medium placed on a first member and a magnetic sensor placed on the second member, the first and second member for moving relative to each other. The magnetic sensor includes a sensor substrate, a sensor holding plate for holding the sensor substrate, and a wire for extracting a signal from the magneto-resistive element to outside. The sensor holding plate includes a fixing portion for fixing the sensor holding plate to the second member, a sensor holding member for holding the sensor substrate, and a plurality of arm portions provided in the relative movement direction with the sensor holding member in-between and extending from the fixing portion to constitute a cantilever.

主权项

1. A magnetic encoder, comprising:
a magnetic medium placed on a first member and a magnetic sensor placed on a second member, the first member and the second member for moving relative to each other, wherein the magnetic sensor includes
a sensor substrate having a magneto-resistive element mounted thereon for detecting a magnetic field emanating from the magnetic medium, for reciprocatively sliding relative to the magnetic medium;a sensor holding plate for holding the sensor substrate; anda wire for extracting a signal from the magneto-resistive element to outside, the sensor holding plate includes
a fixing portion for fixing the sensor holding plate to the second member;a sensor holding member for holding the sensor substrate; anda plurality of arm portions provided in the direction of relative movement, with the sensor holding member in-between, and extending from the fixing portion so as to each constitute a cantilever, and the arm portion has a portion of which width becomes larger either continuously or stepwisely from a side of the sensor holding member toward the fixing portion, and the arm portion has a slit arranged in a horizontal direction and a connecting portion that extends from the slit portion connecting the arm portion to the sensor holding plate.