Laser beam system for optically recording information signals on a record disc
US4115809A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 29, 1976 |
| Grant date | Sep 19, 1978 |
| Priority date | — |
| Expiry date | Nov 29, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24085
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The inventive system optically records information signals on a recording disc. A light source, such as a laser beam, for example, emits a light which is modulated in conformance with an information signal that is to be recorded. An optical system converts this light into a beam having a large width in the longitudinal direction of a track formed on the recording disc. There is a small beam dimension in the transverse direction of the track. A slit plate within the optical system limits the width of the light to cause a constant beam width in the transverse direction of the track. A focusing lens receiving, as incident light, such a limited light beam forms a light spot on the recording disc which is small in the longitudinal direction of the track and large in the transverse direction of the track. The light spot forms a plurality of pits in the upper surface of the recording disc. Each of these pits has a small width in the longitudinal direction of the track and a constant large width in the transverse direction of the track, thereby to record the information signal along the track on the recording disc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.