Optical disc cloud analyzer
US5726748A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 24, 1996 |
| Grant date | Mar 10, 1998 |
| Priority date | — |
| Expiry date | Jul 24, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9506
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An analyzer is employed for detecting a cloud in an optical disc having a transparent surface layer atop a substrate and data pits therebetween. A light beam is projected at an acute incidence angle atop the surface layer to define a light spot covering a plurality of the pits. Light scattered from the pits below the spot is detected obliquely to both the incident light beam and a specular reflection thereof. The light spot is scanned over the surface layer, and variation of detected light intensities over the disc is determined for detecting a cloud. In a preferred embodiment, the scattered light is detected from two different oblique directions to increase contrast of the cloud.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.