Combined birefringent material and reflective waveguide for multiple focal planes in a mixed-reality head-mounted display device
US11953686B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2021 |
| Grant date | Apr 9, 2024 |
| Priority date | — |
| Expiry date | Feb 23, 2042 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0187
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical combiner in a display system of a mixed-reality head-mounted display (HMD) device comprises a lens of birefringent material and a ferroelectric liquid crystal (FLC) modulator that are adapted for use with a reflective waveguide to provide multiple different focal planes on which holograms of virtual-world objects (i.e., virtual images) are displayed. The birefringent lens has two orthogonal refractive indices, ordinary and extraordinary, depending on the polarization state of the incident light. Depending on the rotation of the polarization axis by the FLC modulator, the incoming light to the birefringent lens is focused either at a distance corresponding to the ordinary refractive index or the extraordinary refractive index. Virtual image light leaving the birefringent lens is in-coupled to a see-through reflective waveguide which is configured to form an exit pupil for the optical combiner to enable an HMD device user to view the virtual images from the source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.