Diffractive optical elements with varying direction for depth modulation
US9864208B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2015 |
| Grant date | Jan 9, 2018 |
| Priority date | — |
| Expiry date | Apr 4, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0178
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In an optical display system that includes a waveguide with multiple diffractive optical elements (DOEs), one or more of the DOEs is configured with gratings that have varying depth and varying directions for depth modulation, in which the modulation direction is aligned with the steepest change (i.e., slope) of grating depth. Depth modulation direction may change at a point of transition between different regions in the DOE. For example, with a zero axis being defined along a line parallel to a long side of a DOE, the depth modulation direction can change from a negative angle, with respect to the axis in the plane of the waveguide in one region, to a positive angle in another region, or vice versa. By varying depth modulation direction in a DOE, display uniformity in the optical display system may be increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.