Apparatus and method for adjusting focus of a multi-element optical detector
US4810091A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 30, 1987 |
| Grant date | Mar 7, 1989 |
| Priority date | — |
| Expiry date | Dec 30, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/2803
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A multi-element optical detector having a planar array of detector elements is focused at the focal plane of an optical spectrometer by placing the detector with the detecting surface of the array facing the optical spectrometer and being substantially perpendicular to the axis of the path of the light from the optical spectra to the focal plane. Relative movement is provided between the detector and the focal plane along said axis so that the detector array is placed at several different positions with respect to the focal plane. At each position the output values of the detector elements of the array are measured and the second difference of the output values is determined by the equation (-F1+2.times.F2-F3), where F1, F2, and F3 are the output values of three of the elements. The optical detector is placed at the position which provides the maximum value of the second difference, which is the position of the focal plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.