Relative-rotational-position detection apparatus
US6581479B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 2002 |
| Grant date | Jun 24, 2003 |
| Priority date | — |
| Expiry date | Apr 11, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L3/105
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An outer cylinder having patterns of open windows of first to fourth channels is formed of a magnetic-shielding or antimagnetic substance. An inner cylinder is inserted in the outer cylinder, is formed of a magnetic substance and has patterns of nonmagnetic windows of the first to fourth channels. First to fourth coils excitable by A.C. are provided for the first to fourth channels. For each of the channels, the pattern of the open window in the outer cylinder and the pattern of the nonmagnetic window in the inner cylinder are arranged to overlap with each other. Arrangement of the windows in the channels is set such that: degree of overlap between the pattern of the open window and the pattern of the nonmagnetic window in each of the channels varies in accordance with a variation in a relative rotational position to be detected; a variation in the degree of overlap in the second channel presents a differential characteristic relative to a variation in the degree of overlap in the first channel; a variation in the degree of overlap in the fourth channel presents a differential characteristic relative to a variation in the degree of overlap in the third channel; and variations in th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.