Optical element and image display apparatus
US12393045B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 2022 |
| Grant date | Aug 19, 2025 |
| Priority date | — |
| Expiry date | Apr 11, 2044 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B2027/0178
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical element includes a light guide plate, an incidence portion, and an emission portion, in which the incidence/emission portion includes an Λ1 diffraction element having a diffraction period Λ1, an Λ2 diffraction element having a diffraction period Λ2, and an Λ3 diffraction element having a diffraction period Λ3, “Λ1:Λ2:Λ3=1:1√2±0.015:1/2±0.015” is satisfied, an angle between periodic directions of the Λ1 diffraction element and the Λ2 diffraction element and an angle between periodic directions of the Λ2 diffraction element and the Λ3 diffraction element is 45° or 135° (±0.5°), and an angle between the periodic directions of the Λ2 diffraction elements in the incidence portion and the emission portion is any one of 0°, 90°, 180°, or 270° (±0.5°).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.