Electrical zeroing of light beam
US4265536A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1979 |
| Grant date | May 5, 1981 |
| Priority date | — |
| Expiry date | Jun 25, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N30/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus for measuring deflection of a light beam by sensing the beam with means providing two optical measurements, and providing an electrical output dependent upon the difference between the two measurements, with the instantaneous magnitude of each measurement being dependent upon the instantaneous deflection of the beam and upon the instantaneous intensity of the beam, the apparatus including electrical circuitry for including in the output an offset term dependent upon a scale factor and upon the instantaneous magnitude of at least one of the measurements, thereby making the offset term dependent upon the instantaneous intensity of the light beam, and means for initially zeroing the apparatus by adjusting the scale factor so as to make the output equal to a predetermined base value, whereby changes in the measurements due to changes in light beam intensity are offset by corresponding changes in the offset term, so as to thereby reduce the influence of beam intensity on the output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.