Optical disk thickness discriminating apparatus
US5831952A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 1996 |
| Grant date | Nov 3, 1998 |
| Priority date | — |
| Expiry date | Jul 25, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disk apparatus comprising a device for moving a focal point of a light beam for reproducing information recorded on an information face of a disk, in the direction perpendicular to the information face; a device for detecting a reflected light from the disk; and a device for discriminating whether the disk set in the apparatus is a disk having a thick base substrate or a disk having a thin base substrate. In this apparatus, a maximum value AS1L.sub.max of an output signal from the reflected light detecting device and a maximum value ENV.sub.max of an amplitude of an information reproducing signal are detected while driving the focal point moving device so that the focal point passes through the information face, and the discriminating device discriminates whether the disk set in the apparatus is a disk having a thick base substrate or a disk having a thin base substrate, on the basis of the ratio of ENV.sub.max to AS1L.sub.max. Therefore, it is possible to discriminate between a DVD having a thin base substrate and a CD having a thick base substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.