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EP-4273601-B1 - METHODS AND APPARATUSES FOR REDUCING STRAY LIGHT EMISSION FROM AN EYEPIECE OF AN OPTICAL IMAGING SYSTEM

EP4273601B1EP 4273601 B1EP4273601 B1EP 4273601B1EP-4273601-B1

Inventors

  • YARAS, Fahri
  • BROWY, ERIC C.
  • LIU, Victor Kai
  • BHARGAVA, SAMARTH
  • SINGH, VIKRAMJIT
  • VAUGHN, MICHAL BEAU DENNISON
  • SAWICKI, JOSEPH CHRISTOPHER

Dates

Publication Date
20260506
Application Date
20180927

Claims (14)

  1. An eyepiece for a head-mounted display, comprising: one or more first planar waveguides (108) arranged to receive light from a spatial light modulator (106) at a first edge (128), guide at least some of the received light to a second edge opposite the first edge, and extract at least some of the light through a face (116) of the one or more first planar waveguides between the first and second edges; characterized in that the eyepiece further comprises a second waveguide (504) positioned to receive light exiting the one or more first planar waveguides at the second edge and guide the received light to one or more light absorbers (506), the light absorbers comprising an optically dark material.
  2. The eyepiece of claim 1, further comprising optical structures (704) arranged between the second edge of the one or more first planar waveguides and the second waveguide (504), the optical structures being configured to couple light from the one or more first planar waveguides into the second waveguide.
  3. The eyepiece of claim 1, further comprising a reflector, the second waveguide (504) being arranged between the reflector and the one or more first planar waveguides (108), the reflector being configured to reflect light that enters the second waveguide from the one or more first planar waveguides so that the light is guided to the one or more light absorbers (506).
  4. The eyepiece of claim 1, wherein the head-mounted display is configured to display content to a user according to a field of view, and wherein the one or more absorbers (506) are located out of the field of view.
  5. The eyepiece of claim 1, further comprising one or more additional waveguides positioned to receive light exiting the one or more first planar waveguides at one or more additional edges of the one or more first planar waveguides, and guide the received light from the one or more additional edges to one or more additional light absorbers.
  6. The eyepiece of claim 1, wherein the one or more first planar waveguides (108) are located in a field of view of a user during operation of the head-mounted display by the user.
  7. The eyepiece of claim 1, wherein the one or more first planar waveguides (108) comprise one or more diffractive optical elements (110) extending between the first edge and the second edge, wherein the one or more diffractive optical elements are configured to extract at least some of the light through a face of the one or more first planar waveguides between the first and second edge, preferably wherein at least one of the one or more diffractive optical elements is disposed within an interior of the one or more first planar waveguides or along a periphery of the one or more first planar waveguides.
  8. The eyepiece of claim 1, wherein the eyepiece further comprises: a third planar waveguide arranged to receive light from the spatial light modulator (106) at a third edge, guide at least some of the received light to a fourth edge opposite the third edge, extract at least some of the light through a face of the third planar waveguide between the third and fourth edges; and a fourth waveguide positioned to receive light exiting the third planar waveguide at the fourth edge and guide the received light to one or more second light absorbers, wherein the third planar waveguide and the fourth planar waveguide are arranged in a stack with the first planar waveguide (106) and second waveguide (504).
  9. The eyepiece of claim 1, wherein the second waveguide (504) defines a grating pattern along its periphery.
  10. The eyepiece of claim 9, wherein the second waveguide (504) is integral with the one or more first planar waveguides (108), preferably wherein the grating pattern is defined on at least one of a first face of the second waveguide or second face of the second waveguide, the first face of the second waveguide being opposite to the second face of the second waveguide.
  11. The eyepiece of claim 9, wherein the second waveguide (504) is distinct from the one or more first planar waveguides (108).
  12. The eyepiece of claim 9, further comprising a light absorbing material deposited along the grating pattern, preferably wherein the grating pattern is defined along an entirely of the periphery of the second waveguide (504), the light absorbing material is deposited along an entirely of the periphery of the second waveguide, the grating pattern is defined along a subset of the periphery of the second waveguide, or the light absorbing material is deposited along a subset of the periphery of the second waveguide.
  13. The eyepiece of claim 1, comprising an optical coupler subsystem (104) configured to receive the light from the spatial light modulator (106) and direct the light in a first direction towards the first edge (128) of the one or more first planar waveguides (108) along a primary emission axis.
  14. The eyepiece of claim 13, wherein the second waveguide (504) comprises a peripheral edge in a second direction from the optical coupler subsystem (104), the second direction being opposite from the first direction, the peripheral edge being inclined with respect to the primary emission axis.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of the filing date of U.S. Provisional Application No. 62/564,528, filed on September 28, 2017. TECHNICAL FIELD This disclosure relates to components for reducing stray light emission in an eyepiece for a head-mounted display. BACKGROUND Imaging systems can be used to present visual information to a user. For example, an imaging system can include an optical component that projects images onto an imaging surface, such that one or more users can view the image. In some cases, imaging systems can be incorporated into a head-mounted display device to present visual information in a more immersive manner. For example, head-mounted displays can be used to present visual information for virtual reality (VR) or augmented reality (AR) systems. Patent document US 2017/0255016 A1 discloses systems and methods for selectively incoupling light having different wavelengths into one of a plurality of waveguides using reflective switching. SUMMARY The invention is defined by the attached set of claims. In an aspect, an eyepiece for a head-mounted display includes one or more first planar waveguides arranged to receive light from a spatial light modulator at a first edge, guide at least some of the received light to a second edge opposite the first edge, and extract at least some of the light through a face of the one or more first planar waveguides between the first and second edges. The eyepiece also includes a second waveguide positioned to receive light exiting the one or more first waveguides at the second edge and guide the received light to one or more light absorbers, the light absorbers comprising an optically dark material. Implementations of this aspect can include one or more of the followign features. In some implementations, the eyepiece can further include optical structures arranged between the second edge of the one or more first waveguides and configured to couple light from the one or more first waveguides into the second waveguide. In some implementations, the eyepiece can further include a reflector. The second waveguide can be arranged between the reflector and the one or more first waveguides. The reflector can be configured to reflect light that enters the second waveguide from the one or more first waveguides so that the light is guided to the one or more light absorbers. In some implementations, the one or more absorbers can be located out of a field of view of a user during operation of the head-mounted display by the user. In some implementations, the eyepiece can further include one or more additional waveguides positioned to receive light exiting the one or more first waveguides at one or more additional edges of the one or more first waveguides, and guide the received light from the one or more additional edges to one or more additional light absorbers. In some implementations, the one or more first waveguides can be located in a field of view of a user during operation of the head-mounted display by the user. In some implementations, the one or more first waveguides can include one or more diffractive optical elements extending between the first edge and the second edge. The one or more diffractive optical elements can be configured to extract at least some of the light through a face of the one or more first waveguides between the first and second edge. In some implementations, at least one of the one or more diffractive optical elements can be disposed within an interior of the one or more first waveguides. In some implementations, at least one of the one or more diffractive optical elements can be disposed along a periphery of the one or more first waveguides. In some implementations, the eyepiece can further include a third waveguide arranged to receive light from the spatial light modulator at a third edge, guide at least some of the received light to a fourth edge opposite the third edge, extract at least some of the light through a face of the third waveguide between the third and fourth edges. The eyepiece can further include a fourth waveguide positioned to receive light exiting the third waveguide at the fourth edge and guide the received light to one or more second light absorbers. In some implementations, the second waveguide can be define a grating pattern along its periphery. In some implementations, the second waveguide can be integral with the one or more first waveguides. In some implementations, the grating pattern can be defined on at least one of a first face of the second waveguide or second face of the second waveguide. The first face of the second waveguide can be opposite to the second face of the second waveguide. In some implementations, the second waveguide can be distinct from the one or more first waveguides. In some implementations, the eyepiece can further include a light absorbing material deposited along the grating pattern. In some implementations, the grating pattern can be defined a