Phase-measurement device
US5723989A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 17, 1996 |
| Grant date | Mar 3, 1998 |
| Priority date | — |
| Expiry date | May 17, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R25/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device for determining the phase difference between a first and a second digital input signal (S1, S2) is disclosed. In a first embodiment, a clock signal (CLOCK) is supplied as a first counting signal (18) to a first counter (16), which is reset by the appearance of a predetermined edge (31) of the first input signal (S1). This embodiment permits phase measurement values in the range between zero and 360.degree. to be generated at a high measurement rate. In second and third embodiments, which are preferably connected and, if desired, combined with the first embodiment, second and third switching signals (FORWARD, BACK) are generated from the digital input signals (S1, S2) and are supplied to a forward-backward counter (20). The second and third embodiments are suited for determining phase differences between the two digital input signals (S1, S2) which are multiples of 360.degree.. The device in accordance with the invention is particularly suited for evaluating the phase difference which occurs between the output signals from two photoelectric detectors used in a heterodyne interferometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.