Optical head and information storage device
US7106664B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2005 |
| Grant date | Sep 12, 2006 |
| Priority date | — |
| Expiry date | Apr 4, 2025 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB82Y10/00
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical head including a first dielectric layer having a first refractive index, a pair of second dielectric layers located adjacent to the first dielectric layer on both sides thereof, each of the second dielectric layers having a second refractive index larger than the first refractive index, a pair of third dielectric layers located adjacent to the second dielectric layers, and a pair of fourth dielectric layers located adjacent to the third dielectric layers, each of the fourth dielectric layers having a third refractive index larger than the first refractive index. Light is incident on the optical head in a direction orthogonal to a layering direction of the first to fourth dielectric layers. The first dielectric layer and each of the third dielectric layers have different refractive indices or different thicknesses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.