Displacement pickup
US7034948B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 2003 |
| Grant date | Apr 25, 2006 |
| Priority date | — |
| Expiry date | Sep 25, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/34707
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A displacement pickup is provided which includes a displaceable scale (12) having defined therein a first area (12a) where positional information is recorded with a predetermined pitch and a second area (12b) where positional information is recorded with a predetermined pitch different from that in the first area (12a), a first reading system (10) to read the positional information recorded in the first area (12a), a first phase detector (14) to detect a first phase on the basis of the positional information read by the first reading system (10), a second reading system (11) to read the positional information recorded in the second area (12b), a second phase detector (15) to detect a second phase on the basis of the positional information read by the second reading system (11), a phase comparator (16) to make a comparison between the first and second phases, and an origin signal generator (17) to generate an origin signal according to the result of comparison from the phase comparator (16).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.