Optical pick-up apparatus, optical element, and objective lens having diffracting section
US6671247B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 2000 |
| Grant date | Dec 30, 2003 |
| Priority date | — |
| Expiry date | Oct 27, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical pickup apparatus for a first optical medium including a first transparent base plate having a thickness of t1 and a second optical medium including a second transparent base plate having a thickness of t2 (t2>t1), comprises a first light source to emit a first light flux having a wavelength of &lgr;1; a second light source to emit a second light flux having a wavelength of &lgr;2 (&lgr;1<&lgr;2); a converging optical system having an objective lens and a diffracting section and to converge the first light flux or the second light flux onto the first optical medium or the second optical medium; and an optical detector. When the converging optical system converges the second light flux onto the second information recording surface so as to conduct reproducing and/or recording the information of the second optical information recording medium, a spherical aberration has at least one discontinuous portion or at least one substantially discontinuous portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.