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JP-7855275-B2 - Optical system including a two-dimensional extension optical guide element having a retarder element

JP7855275B2JP 7855275 B2JP7855275 B2JP 7855275B2JP-7855275-B2

Inventors

  • ロネン・クリキ
  • エラド・シャーリン
  • ツィオン・アイゼンフェルト
  • シモン・グレイバーニク

Assignees

  • ルーマス リミテッド

Dates

Publication Date
20260508
Application Date
20250623
Priority Date
20210216

Claims (12)

  1. An optical system for directing image illumination incident on a coupled input region to an eye movement box for viewing by the user's eye, wherein the optical system comprises a light guide optical element (LOE) formed from a transparent material, the LOE having a set of mutually parallel main surfaces for supporting the propagation of image illumination by internal reflection within the LOE, A first optical aperture expansion device associated with the first region of the LOE is used to sequentially redirect the image illumination propagating in the first in-plane direction to propagate in the second in-plane direction. A second optical aperture expansion device associated with a second region of the LOE is used to sequentially redirect the image illumination propagating in a second in-plane direction to coupled output from the LOE toward the eye movement box, The present invention further includes an optical retarder positioned between the first region and the second region to rotate the polarization of light deflected by the first optical aperture expander before it reaches the second optical aperture expander, At least one of the first and second optical aperture expansion devices includes a diffractive optical element, An optical system in which the main surfaces extend across the first and second regions such that both the first optical aperture expanding device and the second optical aperture expanding device are located between the main surfaces without any gaps in between.
  2. The optical system according to claim 1, further comprising an image projector optically coupled to the LOE such that the image illumination is incident on the coupled input region of the LOE such that the image illumination is confined in one dimension by internal reflections at the set of main surfaces.
  3. The optical system according to claim 2, wherein the image projector is configured to generate a collimated image.
  4. The optical system according to claim 1, wherein the diffractive optical element is a surface grating.
  5. The optical system according to claim 1, wherein the diffractive optical element is a volume grating.
  6. The optical system according to claim 1, wherein the diffractive optical element is a holographic grating.
  7. The optical system according to claim 1, wherein one of the first and second optical aperture expansion devices includes the diffractive optical element, and the other of the first and second optical aperture expansion devices includes a set of mutually parallel partial reflective surfaces arranged within the LOE.
  8. The optical system according to claim 1, wherein both the first and second optical aperture expansion devices include diffractive optical elements.
  9. The optical system according to claim 1, wherein the retarder is disposed within the LOE so as to extend between the main surfaces substantially perpendicular to the main surfaces.
  10. The optical system according to claim 1, wherein the retarder is disposed within the LOE so as to extend between the main surfaces at an oblique angle to the main surfaces.
  11. The optical system according to claim 1, wherein the retarder is arranged within the LOE so as to be oriented substantially parallel to the main surface.
  12. The optical system according to claim 11, wherein the retarder is oriented substantially adjacent to one of the main surfaces.

Description

The subject matter currently disclosed relates to optical systems, and more specifically, to optical systems including light guide elements (LOEs) configured for two-dimensional image augmentation. In recent years, consumer demand for "smart" eyewear, such as head-mounted displays (HMDs) and augmented reality (AR) glasses, collectively known as near-eye display systems, has been increasing. Therefore, in this rapidly developing technological field, there is a growing need for optics that are smaller and lighter, yet provide a relatively large field of view (FOV) and produce bright, high-quality images. Some known optical systems use waveguides (also referred to herein as “light guides,” “light guide optical elements,” or “LOEs”) to propagate an input image along a substrate embedded with one or more partially reflective inner surfaces (“facets”), thereby magnifying the input image. One known problem with this type of optical system is that a small amount of light is lost due to polarization mismatch between partial reflections from non-parallel facets. To understand the present invention and to see how it can be put into practice, embodiments will be described as non-limiting examples with reference to the accompanying drawings: Figures 1A-1D show an example of a near-eye display system using LOE for 2D image magnification according to prior art. Figures 1A-1D show an example of a near-eye display system using LOE for 2D image magnification according to prior art. Figures 1A-1D show an example of a near-eye display system using LOE for 2D image magnification according to prior art. Figures 1A-1D show an example of a near-eye display system using LOE for 2D image magnification according to prior art. Figures 2A and 2B show enlarged views of the LOE in Figures 1A and 1B according to the prior art. Figures 2A and 2B show enlarged views of the LOE in Figures 1A and 1B according to the prior art. Figure 3 shows the reflectivity characteristics of a ray of light at a certain incident angle in the S-polarized and P-polarized states. Figure 4 shows a retarder embedded in a LOE according to one embodiment of the disclosed subject matter. Figures 5A–5E show various configurations of the retarder 40 having LOE according to the disclosed embodiment of the subject matter. Figures 5A–5E show various configurations of the retarder 40 having LOE according to the disclosed embodiment of the subject matter. Figures 5A–5E show various configurations of the retarder 40 having LOE according to the disclosed embodiment of the subject matter. Figures 5A–5E show various configurations of the retarder 40 having LOE according to the disclosed embodiment of the subject matter. Figures 5A–5E show various configurations of the retarder 40 having LOE according to the disclosed embodiment of the subject matter. Figures 6A-6C show known manufacturing methods for optical polarization retarders. Figures 6A-6C show known manufacturing methods for optical polarization retarders. Figures 6A-6C show known manufacturing methods for optical polarization retarders. Figures 7A-7D show one embodiment of a method for manufacturing an LOE having an embedded retarder according to an embodiment of the subject disclosed, Figures 7A-7D show one embodiment of a method for manufacturing an LOE having an embedded retarder according to an embodiment of the subject disclosed, Figures 7A-7D show one embodiment of a method for manufacturing an LOE having an embedded retarder according to an embodiment of the subject disclosed, Figures 7A-7D show one embodiment of a method for manufacturing an LOE having an embedded retarder according to an embodiment of the subject disclosed, Figures 8A–8E show an example of a method for manufacturing an LOE having an embedded retarder, according to another embodiment of the disclosed subject matter, and Figures 8A–8E show an example of a method for manufacturing an LOE having an embedded retarder, according to another embodiment of the disclosed subject matter, and Figures 8A–8E show an example of a method for manufacturing an LOE having an embedded retarder, according to another embodiment of the disclosed subject matter, and Figures 8A–8E show an example of a method for manufacturing an LOE having an embedded retarder, according to another embodiment of the disclosed subject matter, and Figures 8A–8E show an example of a method for manufacturing an LOE having an embedded retarder, according to another embodiment of the disclosed subject matter, and Figures 9A and 9B show an embodiment of a diffraction LOE with an embedded retarder. Figures 9A and 9B show an embodiment of a diffraction LOE with an embedded retarder. In the following detailed description, numerous specific examples are described in detail to provide a complete understanding of the present invention. However, those skilled in the art will understand that the subject matter currently disclosed can be carried out without these specific details. In other embodiment