Holographic disk scanner having special position-indicating holograms
US4758058A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 1987 |
| Grant date | Jul 19, 1988 |
| Priority date | — |
| Expiry date | Jan 12, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/106
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A holographic scanner includes a rotating glass disk carrying a plurality of scan line generating holograms, a laser light source and means for detecting reflected optical energy. The scanner is improved by adding a plurality of relatively small position-indicating holograms in alternation with the scan line generating holograms. The position-indicating holograms redirect the laser beam along desired paths on the same side of the disk as the laser. The redirected laser beam may be detected by the system photodetector or an auxiliary photodetector to provide signals indicating the current disk position. The position information can be used by a system processor to optimize scanner parameters as a function of the characteristics of the next active scan line generating hologram.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.