Hologram optical element, fabrication method thereof, and image display apparatus
US7999982B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2008 |
| Grant date | Aug 16, 2011 |
| Priority date | — |
| Expiry date | Oct 11, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2222/55
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A volume-phase reflection hologram optical element is fabricated by exposing a hologram photosensitive material to two coherent light beams. One exposure light beam has an axis-asymmetric wavefront, and the other exposure light beam has focus points different in the optical axis direction (Z-direction) between on a plane (ZX-plane) including one of two directions (X- and Y-directions) mutually perpendicular on a sectional plane perpendicular to that light beam and on a plane (YZ-plane) including the other of those two directions. Thus, an image display apparatus is realized in which at the time of reproduction, the component of a predetermined wavelength of the image light diffraction-reflected by the hologram optical element is focused at positions different in the optical axis direction between on the ZX-plane and on the YZ-plane, offering different image viewing characteristics between in the X- and Y-directions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.