Optical head device including an optically anisotropic diffraction grating and process for its production
US6271966A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2000 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Mar 13, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/22
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An object is to provide an optical head device whereby the light utilization efficiency can be increased and which can be produced at a low cost. A glass substrate 1 having projections and recesses 2 formed by patterning a SiON type transparent thin film on its inner surface by dry etching, and a second glass substrate 3 having a polyimide film 4 formed as an alignment film on its inner surface, are laminated with a space, the periphery is sealed by a sealing material made of an epoxy resin 5, and liquid crystal 6 is injected under vacuum into the interior to form an optically anisotropic diffraction grating. On the outer surface of this second glass substrate 3, a quarter-wave film 7 is laminated, and a third glass substrate 9 is bonded by a photopolymer 8 to obtain a diffracting element 10. This diffracting element 10 is disposed between a light source and an optical recording medium to obtain an optical head device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.