Displacement detecting apparatus
US6031885A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1997 |
| Grant date | Feb 29, 2000 |
| Priority date | — |
| Expiry date | Sep 3, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/24404
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A displacement detecting apparatus outputs a displacement information signal obtained by interpolating a phase modulation. A direction block obtains a direction signal indicative whether the cycle of the phase modulation signal is longer than the cycle of the reference signal. A phase difference block obtains the number of the interpolation clock pulses which number corresponds to a phase difference between the phase modulation signal and the reference signal. An up/down counter counts to an interpolation number upon receiving the direction signal and a pulse train corresponding to the phase difference. The presetting block presets the number of pulses corresponding to the phase difference in the up/down counter. The displacement information block outputs a Glay code converted from continuous 2 bits of the count value of the up/down counter as displacement information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.