Apparatus for detecting the presence of an optical disk
US5418766A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1993 |
| Grant date | May 23, 1995 |
| Priority date | — |
| Expiry date | Dec 9, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0037
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical disk apparatus which can exactly determine whether or not an optical disk is loaded therein in a short time. The optical disk apparatus determines the presence of the optical disk having a transparent film provided on a recording surface by means of a focusing performed by an optical pick-up. The optical pick-up receives a reflected light beam reflected by the optical disk and splits the received light beam into at least two light beams so as to output signals corresponding to each of the split light beams. A controlling unit controls a movement of the optical pick-up in a direction perpendicular to the recording surface of the optical disk. A signal generating unit generates a focus error signal when signals corresponding to the reflected light beam are supplied by the optical pick-up. A determining unit determines whether or not the optical disk is loaded in the optical disk apparatus by counting the number of the focus error signals. The determination is carried out while the optical pick-up travels in a single direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.