Aberration correcting apparatus and optical apparatus using the same
US6320699A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 2000 |
| Grant date | Nov 20, 2001 |
| Priority date | — |
| Expiry date | Feb 10, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0948
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An aberration correcting apparatus and an optical pickup apparatus using this apparatus, in which a spherical aberration based on a thickness error of an optical disc substrate can be preferably eliminated and a thickness error permission range of the optical disc substrate can be widened even if an objective lens of a high numerical aperture is used. The aberration correcting apparatus is arranged on an optical axis of an optical path in an optical apparatus, the aberration correcting apparatus comprises a pair of light transmitting substrates each of which is arranged so as to intersect perpendicularly to the optical axis, wherein at least one of the light transmitting substrates is held rotatably around the optical axis, each of the light transmitting substrates has distributions of optical path lengths which mutually complementarily decrease or increase within a predetermined range on a concentric circle in which the optical axis is set to the center, and the distribution of the total optical path length of the pair of light transmitting substrates is uniformly changed within the predetermined range on the concentric circle in which the optical axis is set to the center in acco…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.