Projector architecture incorporating artifact mitigation
An artifact mitigation system includes a projector assembly and a set of imaging optics optically coupled to the projector assembly. The artifact mitigation system also includes an eyepiece optically coupled to the set of imaging optics. The eyepiece includes a diffractive incoupling interface. The artifact mitigation system further includes an artifact prevention element disposed between the set of imaging optics and the eyepiece. The artifact prevention element includes a linear polarizer, a first quarter waveplate disposed adjacent the linear polarizer, and a color select component disposed adjacent the first quarter waveplate.
1. An artifact mitigation system comprising:
a projector assembly;
a set of imaging optics optically coupled to the projector assembly;
an eyepiece optically coupled to the set of imaging optics, wherein the eyepiece includes a diffractive incoupling interface and the set of imaging optics is configured to form an image at the diffractive incoupling interface; and
an artifact prevention element disposed between the projector assembly and the set of imaging optics, the artifact prevention element including a circular polarizer.
2. The artifact mitigation system of claim 1 , wherein the circular polarizer comprises:
a linear polarizer; and
a quarter waveplate disposed adjacent the linear polarizer.
3. The artifact mitigation system of claim 2 , wherein:
the linear polarizer is configured to pass a light beam characterized by a first linear polarization; and
the quarter waveplate is configured to convert the light beam characterized by the first linear polarization to a light beam characterized by an elliptical polarization and to pass the light beam characterized by the elliptical polarization.
4. The artifact mitigation system of claim 3 , wherein the set of imaging optics is configured to reflect a return portion of the light beam characterized by the elliptical polarization, wherein the return portion of the light beam is characterized by an opposite handedness to the light beam characterized by the elliptical polarization.
5. The artifact mitigation system of claim 4 , wherein the quarter waveplate is configured to convert the return portion of the light beam characterized by the opposite handedness to a linearly polarized return portion.
6. The artifact mitigation system of claim 5 , wherein the linear polarizer is configured to attenuate the linearly polarized return portion.
7. The artifact mitigation system of claim 5 , wherein the linearly polarized return portion is perpendicular to the first linear polarization.
8. The artifact mitigation system of claim 1 , wherein the projector assembly further comprises:
a polarization beam splitter (PBS);
a set of spatially displaced light sources disposed adjacent to the PBS; and
a display panel disposed adjacent to the PBS,
wherein the set of imaging optics is disposed adjacent to the PBS.
9. The artifact mitigation system of claim 8 , wherein the set of spatially displaced light sources includes a set of three LEDs having different colors.
10. The artifact mitigation system of claim 1 , wherein the projector assembly further comprises:
a polarization beam splitter (PBS);
a set of spatially displaced light sources disposed adjacent to a first side of the PBS;
a collimator disposed adjacent to a second side of the PBS; and
a display panel disposed adjacent to a third side of the PBS, wherein the set of imaging optics is disposed adjacent a fourth side of the PBS and wherein the fourth side is positioned between the first side and the third side and opposite to the second side.
11. The artifact mitigation system of claim 10 , wherein the set of spatially displaced light sources includes a set of three LEDs having different colors.
12. The artifact mitigation system of claim 10 , wherein the display panel comprises a liquid crystal on silicon (LCOS) spatial light modulator (SLM).
13. The artifact mitigation system of claim 10 , wherein the collimator is a mirrored lens, a reflective lens, or a curved reflector.
14. The artifact mitigation system of claim 1 wherein the diffractive incoupling interface is operable to couple light in a first wavelength range and a second wavelength range into the eyepiece.
15. The artifact mitigation system of claim 14 wherein the artifact prevention element is operable to transmit light in the first wavelength range.
16. The artifact mitigation system of claim 1 wherein the artifact prevention element comprises a retarder stack film (RSF) filter.
17. The artifact mitigation system of claim 1 wherein the diffractive incoupling interface is coupled to a waveguide element.
18. The artifact mitigation system of claim 1 wherein the artifact prevention element is disposed a predetermined distance from the eyepiece, the predetermined distance being measured normal to the eyepiece.
19. The artifact mitigation system of claim 1 wherein the diffractive incoupling interface comprises:
a first incoupling grating coupled to a first waveguide;
a second incoupling grating coupled to a second waveguide; and
a third incoupling grating coupled to a third waveguide.