Apparatus for positioning a rotating element
US4705996A · kind A · utility
4Cited by
5References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1986 |
| Grant date | Nov 10, 1987 |
| Priority date | — |
| Expiry date | Oct 9, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/37131
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The position of a rotating element is controlled by a galvanometer and a servo system. The position of the rotating element is determined by using a two-grating moire pattern. Movement of the element causes a projected scale image representing radiation reflected from the element to shift relative to a fixed grating thereby generating moire fringes. The accumulated fringes serve to measure absolute position and motion of the element. The servo digitally processes the measured position to generate several force components which are then combined to control the amount of force applied by the galvanometer to rotate the element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.