Rotary head scanner including anamorphic beam-shaping apparatus in an optical signal-transmission channel
US4819096A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1988 |
| Grant date | Apr 4, 1989 |
| Priority date | — |
| Expiry date | Jun 27, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B15/14
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Rotary scanner apparatus includes a magnetic head on the periphery of a rotatable headwheel having a central axis of rotation, and an off-axis light source for projecting a collimated beam of information-bearing light obliquely onto a planar photodetector on the axis of the headwheel. To optimize electro-optical "action", and thereby enhance signal-to-noise ratio, optical apparatus, interposed between the light source and the photodetector, has an optical characteristic for shaping the light beam, to cuase the size and shape of its cross section, at a plane of incidence coinciding with the photodetector, to correspond substantially to the size and shape of the light-sensitive surface of the photodetector. Preferably, the optical apparatus includes a prism pair of performing anamorphic beam contraction, to convert the beam shape to circular, in its plane of incidence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.