Off axis rotation of diffraction grating
US5015069A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1989 |
| Grant date | May 14, 1991 |
| Priority date | — |
| Expiry date | Feb 17, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2003/066
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a spectrophotometer application where high speed positioning is critical, a galvanometer in conjunction with a microprocessor controlled hybrid digital/analog servo system is used to rotate a diffraction grating for wavelength selection. A table containing digital position information for all wavelengths is accessed by the microprocessor to perform wavelength changes. The use of the table permits the determination of grating position to yield a desired wavelength for a system where the axis of rotation does not intersect a point on the surface of the diffraction grating. That is, the diffraction grating can be rotated about an axis coinciding with its center of gravity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.