Apparatus for optically scanning a radiation-reflecting information plane
US4908506A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1989 |
| Grant date | Mar 13, 1990 |
| Priority date | — |
| Expiry date | Mar 14, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1353
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Optical scanning apparatus which includes a diode laser producing a radiation beam which is focussed by a lens system on a reflecting information plane to be scanned thereby. The reflected radiation is diffracted by a composite diffraction grating which includes a pair of sub-gratings, forming respective radiation spots on respective pairs of radiation detectors. The detectors in each pair are separated by a separating strip, the separating strips being substantially parallel to or co-linear with the bonding line between the sub-gratings. Such arrangement achieves correction for wavelength variations of the radiation beam, as well as fairly wide tolerances in the relative positioning of the various optical elements of the apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.