Methods and apparatuses for reducing stray light emission from an eyepiece of an optical imaging system
View Patent ↗An eyepiece for a head-mounted display includes one or more first 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 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.
1. An eyepiece for a head-mounted display, comprising:
one or more first 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 waveguides between the first and second edges;
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 first light absorbers;
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; and
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.
2. The eyepiece of claim 1 , further comprising 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.
3. The eyepiece of claim 1 , further comprising a reflector, the second waveguide being arranged between the reflector and the one or more first waveguides, the reflector being 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 first light absorbers.
4. The eyepiece of claim 1 , wherein the one or more absorbers are located out of a field of view of a user during operation of the head-mounted display by the user.
5. The eyepiece of claim 1 , further comprising 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.
6. The eyepiece of claim 1 , wherein the one or more first waveguides 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 waveguides comprise one or more diffractive optical elements 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 waveguides between the first and second edge.
8. The eyepiece of claim 7 , wherein at least one of the one or more diffractive optical elements is disposed within an interior of the one or more first waveguides.
9. The eyepiece of claim 7 , wherein at least one of the one or more diffractive optical elements is disposed along a periphery of the one or more first waveguides.
10. The eyepiece of claim 1 , wherein the second waveguide defines a grating pattern along its periphery.
11. The eyepiece of claim 10 , wherein the second waveguide is integral with the one or more first waveguides.
12. The eyepiece of claim 11 , 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.
13. The eyepiece of claim 10 , wherein the second waveguide is distinct from the one or more first waveguides.
14. The eyepiece of claim 10 , further comprising a light absorbing material deposited along the grating pattern.
15. The eyepiece of claim 14 , wherein the grating pattern is defined along an entirely of the periphery of the second waveguide.
16. The eyepiece of claim 14 , wherein the light absorbing material is deposited along an entirely of the periphery of the second waveguide.
17. The eyepiece of claim 14 , wherein the grating pattern is defined along a subset of the periphery of the second waveguide.
18. The eyepiece of claim 14 , wherein the light absorbing material is deposited along a subset of the periphery of the second waveguide.
19. The eyepiece of claim 1 , comprising an optical coupler subsystem configured to receive the light from the spatial light modulator and direct the light in a first direction towards the first edge of the one or more first waveguides along a primary emission axis.
20. The eyepiece of claim 19 , wherein the second waveguide comprises a peripheral edge in a second direction from the optical coupler subsystem, the second direction being opposite from the first direction, the peripheral edge being inclined with respect to the primary emission axis.