Measuring method and apparatus
US4273448A · kind A · utility
Inventor
Key dates
| Filing date | Jun 4, 1979 |
| Grant date | Jun 16, 1981 |
| Priority date | — |
| Expiry date | Jun 4, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2066
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention relates to method and apparatus for improving the accuracy of optical or electrical position measuring apparatus wherein movement of one object relative to another is measured. One known system employs primary and secondary windings each comprising a multiplicity of series-connected conductors arranged on adjacent faces of relatively movable members of insulating material. In another system an optical Moire fringe pattern is moved in correspondence as regards extent and sense with the movement with the object and the number of fringes displaced from a fiducial line are counted. The improvement is applicable to either system and includes placing a series of parallel lines or parallel conductors on the scale or movable object at an angle with respect to the path of movement of the object and placing another set of parallel lines or parallel conductors on the slider or reader followed by providing for controlled movement of the scale transversely of the path of movement of the object to vary the "count" of the lines or conductors on the scale and those on the slider or reader in order to compensate for machine or scale error and render the resulting operational "counts"…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.