Tilting array based display
This disclosure describes a wearable display system configured to project light to the eye(s) of a user to display virtual (e.g., augmented reality) image content in a vision field of the user. The system can include light source(s) that output light, spatial light modulator(s) that modulate the light to provide the virtual image content, and an eyepiece configured to convey the modulated light toward the eye(s) of the user. The eyepiece can include waveguide(s) and a plurality of in-coupling optical elements arranged on or in the waveguide(s) to in-couple the modulated light received from the spatial light modulator(s) into the waveguide(s) to be guided toward the user's eye(s). The spatial light modulator(s) may be movable, and/or may include movable components, to direct different portions of the modulated light toward different ones of the in-coupling optical elements at different times.
1. A head mountable display system configured to project light to an eye of a user to display augmented reality image content in a vision field of the user, the display system comprising:
at least one light source configured to output light;
at least one spatial light modulator arranged to receive at least a portion of the light from the at least one light source and modulate the received light to output modulated light that conveys the augmented reality image content; and
an eyepiece configured to direct, toward the eye of the user, the modulated light that is output by the at least one spatial light modulator, the eyepiece comprising:
a first plurality of waveguides;
a first plurality of in-coupling optical elements on or in the first plurality of waveguides, the first in-coupling optical elements configured to in-couple the modulated light that is output by the at least one spatial light modulator into the first plurality of waveguides to be guided within the first plurality of waveguides; and
a first plurality of out-coupling optical elements on or in the first plurality of waveguides, the first plurality of out-coupling optical elements configured to out-couple light being guided within the first plurality of waveguides out of the first plurality of waveguides toward the eye of the user;
a second plurality of waveguides;
a second plurality of in-coupling optical elements on or in the second plurality of waveguides, the second in-coupling optical elements configured to in-couple the modulated light that is output by the at least one spatial light modulator into the second plurality of waveguides to be guided within the second plurality of waveguides; and
a second plurality of out-coupling optical elements on or in the second plurality of waveguides, the second plurality of out-coupling optical elements configured to out-couple light being guided within the second plurality of waveguides out of the second plurality of waveguides toward the eye of the user;
wherein the at least one spatial light modulator is configured to move to direct, at a first time, a first portion of the modulated light to the first in-coupling optical elements that are on or in the first plurality of waveguides, and to direct, at a second time, a second portion of the modulated light to the second in-coupling optical elements that are on or in the second plurality of waveguides,
wherein the at least one light source is on an opposite side of the eyepiece from the at least one spatial light modulator, and
wherein the at least one light source is arranged to output the light such that the light propagates to the at least one spatial light modulator through a portion of the eyepiece that is between the first plurality of in-coupling optical elements and the second plurality of in-coupling optical elements.
2. The display system of claim 1 , wherein at least a portion of the eyepiece is transparent such that the eyepiece provides a view of a portion of a physical environment while the augmented reality image content is being presented.
3. The display system of claim 1 , further comprising optics having optical power, the optics arranged so as to receive at least a portion of the light output from the at least one light source, the optics arranged with respect to the at least one spatial light modulator such that the light received from the at least one light source passes through the optics and illuminates the at least one spatial light modulator.
4. The display system of claim 3 , wherein the display system is configured such that light illuminating the at least one spatial light modulator is redirected back through the optics and is coupled into at least one of the first plurality of waveguides through at least one of the first plurality of in-coupling optical elements, or is coupled into at least one of the second plurality of waveguides through at least one of the second plurality of in-coupling optical elements.
5. The display system of claim 1 , wherein the first plurality of waveguides comprises a first waveguide that includes a first in-coupling optical element of the first plurality of in-coupling optical elements, and wherein the second plurality of waveguides comprises a second waveguide that includes a second in-coupling optical element of the second plurality of in-coupling optical elements.
6. The display system of claim 5 , wherein the at least one spatial light modulator is configured to tilt to direct more modulated light to the first in-coupling optical element than to the second in-coupling optical element when the at least one spatial light modulator is tilted at a first angle, and wherein the at least one spatial light modulator is configured to tilt to direct more modulated light to the second in-coupling optical element than to the first in-coupling optical element when the at least one spatial light modulator is tilted at a second angle that is different than the first angle.
7. The display system of claim 5 , wherein the first and second waveguides are configured to output light with wavefronts having different amounts of at least one of divergence, convergence, or collimation as if projected from different distances from the eye.
8. The display system of claim 5 , wherein the first and second waveguides are configured such that light out-coupled from the first waveguide is collimated and light out-coupled from the second waveguide diverges.
9. The display system of claim 5 , wherein the first and second waveguides are configured such that light out-coupled from the first waveguide diverges a first amount and light out-coupled from the second waveguide diverges a second amount that is different than the first amount.
10. The display system of claim 5 , wherein the first and second waveguides are configured to output light into different angular fields to extend a field of view for the augmented reality image content presented to the user.
11. The display system of claim 5 , wherein the first waveguide includes a first out-coupling optical element of the first plurality of out-coupling optical elements, wherein the second waveguide includes a second out-coupling optical element of the second plurality of out-coupling optical elements, and wherein first and second out-coupling optical elements are laterally offset with respect to each other so as to provide an increased eye box for the user to view the augmented reality image content.
12. The display system of claim 1 , further comprising:
a controller; and
a rotation stage on which the at least one spatial light modulator is disposed, the rotation stage including at least one actuator configured to tilt the rotation stage in response to a signal received from the controller.
13. The display system of claim 1 , wherein the at least one spatial light modulator is configured to switch between a first state in which the at least one spatial light modulator is tilted at a first angle, and a second state in which the at least one spatial light modulator is tilted at a second angle that is different than the first angle.
14. The display system of claim 13 , wherein the first angle differs from the second angle by at least 7 degrees.
15. The display system of claim 13 , wherein the first angle differs from the second angle by at least 10 degrees.
16. The display system of claim 13 , wherein the first angle differs from the second angle by at least 20 degrees.
17. The display system of claim 13 , wherein the at least one spatial light modulator is configured to switch between the first state and the second state in less than 100 milliseconds.
18. The display system of claim 1 , wherein the at least one spatial light modulator is configured to tilt to direct different amounts of the modulated light having different wavelength ranges to the first plurality of in-coupling optical elements and the second plurality of in-coupling optical elements at different times.
19. The display system of claim 5 , wherein the at least one spatial light modulator is configured to tilt to direct modulated light to the first in-coupling optical element and not to the second in-coupling optical element when the at least one spatial light modulator is tilted at a first angle, and wherein the at least one spatial light modulator is configured to tilt to direct modulated light to the second in-coupling optical element and not to the first in-coupling optical element when the at least one spatial light modulator is tilted at a second angle that is different than the first angle.
20. The display system of claim 1 , wherein different waveguides of at least one of the first or second pluralities of waveguides are configured such that the modulated light that is output from the different waveguides appears to be projected from different depth planes.