Patent ID: 9250102
Filing Date: 2016-02-02
CPC Classification: G01D

Claim Text:
1. A magnetic encoder including plural rows of annular magnetic encoder tracks arranged adjacent to each other, each of the plural rows of magnetic encoder tracks being configured to be read by a corresponding sensor, comprising: an AB magnetic encoder track including a magnetic pattern having N poles and S poles arranged in alternate fashion magnetized thereto to generate magnetic signals for detection of rotation; and a Z magnetic encoder track that is different from the AB magnetic encoder track, the Z magnetic encoder track being adjacent to the AB magnetic encoder track and the Z magnetic encoder track providing a reference position for rotation, each of the AB magnetic encoder track and the Z magnetic encoder track being configured to be employed spaced through an air gap from the corresponding sensors that read magnetic signals of each of the respective magnetic encoder tracks, the magnetic pattern magnetized to the AB magnetic encoder track being configured to have an unequal pitch such that a magnetic pattern of the magnetic signal acting on and read by the corresponding sensor is, under an interference of magnetisms of the AB magnetic encoder track and the Z magnetic encoder track, detected by the corresponding sensor as an equal pitch magnetic pattern.