Objective lens for optical pick-up device and optical pick-up device
US6710939B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 12, 2002 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Nov 12, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2007/0006
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An objective lens is provided with plural optical functional regions including an inside optical functional region, an outside optical functional region and an intermediate optical functional region provided between the inside and outside optical functional regions. The absolute value of an amount of a spherical aberration of a light flux coming to the second optical information recording medium after having passed through the intermediate optical functional region is made larger than that of an amount of a spherical aberration of a light flux coming to the second optical information recording medium after having passed through the inside optical functional region when recording and/or reproducing information is conducted for the second optical information recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.