Position detecting device employing a magnet and back yoke relatively movable with respect to a hall sensor
US5369361A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 16, 1992 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | Jul 16, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/9517
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Disclosed is a position detecting device of magnetic detection type capable of accurate position detection. The device comprises a magnet consisting of an N-pole part and an S-pole part, a back yoke formed with upstanding projections extending up to the surface level of the N-pole part of the magnet, the S-pole part of the magnet being bonded to the central area of the back yoke, and a Hall IC located to make parallel movement relative to both the exposed upper surface of the N-pole part of the magnet and the upper end surfaces of the projections of the back yoke in slightly spaced apart relation. When the Hall IC moves above narrow spaces, which are defined between the magnet and the projections of the back yoke and in each of which the magnetic flux density is zero (the neutral zone between the N pole and the S pole), the threshold of the Hall IC is crossed by the magnetic flux density curve in each of these narrow spaces, so that the position can be detected without any substantial error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.