Projector architecture incorporating artifact mitigation

• US 10,627,559 B2
• Filed: 08/22/2017
• Issued: 04/21/2020
• Est. Priority Date: 08/22/2016
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Magic Leap, Inc.
• Inventors: Curtis, Kevin, Cheng, Hui-Chuan, Greco, Paul M., Welch, William Hudson, Browy, Eric C., Schuck, Miller, Sissom, Bradley Jay
• Primary Examiner(s): Brooks, Jerry L
• Application Number:
  US15/683,412
• Publication Number:
  US 20180052320A1
• Time in Patent Office: 973 Days
• Field of Search: 353 20
• CPC Class Codes: G02B 2027/0114 comprising dichroic elements
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• CPC Class Codes: G02B 2027/014 comprising information/image processing systems
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0018 with means for preventing ghost images anti-reflection coatings G02B1/11
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G02B 27/1086 operating by diffraction only
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 27/30 Collimators
• CPC Class Codes: G02B 5/1823 in an overlapping or superposed manner
• CPC Class Codes: G02B 5/1857 using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams
• CPC Class Codes: G02B 5/1866 Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence
• CPC Class Codes: G02B 5/1871 Transmissive phase gratings
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 6/0016 : Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0023 : provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: G02B 6/0035 : provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0036 : 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0038 : Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/005 : provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0076 : Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G02B 6/29325 : of the slab or planar or plate like form, i.e. confinement in a single transverse dimension only integrated circuit planar waveguide arrangements G02B6/12007; specially adapted for lighting G02B6/0011
• CPC Class Codes: G02B 6/34 : utilising prism or grating G02B6/293 takes precedence
• CPC Class Codes: G02B 7/008 : with means for compensating for changes in temperature or for controlling the temperature; thermal stabilisation
• CPC Class Codes: G02C 11/10 : Electronic devices other than hearing aids
• CPC Class Codes: G02C 5/16 : resilient or with resilient parts
• CPC Class Codes: G06F 1/163 : Wearable computers, e.g. on a belt
• CPC Class Codes: G06F 1/203 : for portable computers, e.g. for laptops
• CPC Class Codes: G06F 1/206 : comprising thermal management
• CPC Class Codes: G06F 3/011 : Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/013 : Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: G06F 3/147 : using display panels
• CPC Class Codes: G09G 2320/0233 : Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2330/045 : Protection against panel overheating
• CPC Class Codes: G09G 2340/0464 : Positioning
• CPC Class Codes: G09G 3/001 : using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/002 : to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/2003 : Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2044 : using dithering
• CPC Class Codes: H04N 9/3102 : using two-dimensional electronic spatial light modulators micromechanical modulators as such G02B26/0833; liquid crystal modulators as such G02F1/13
• CPC Class Codes: H04N 9/3144 : Cooling systems cooling of liquid crystal cells in general G02F1/133382; cooling of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/16
• CPC Class Codes: H04N 9/3164 : using multiple light sources
• CPC Class Codes: H05K 7/20963 : Heat transfer by conduction from internal heat source to heat radiating structure H05K7/20972 takes precedence

Abstract

An artifact mitigation system includes a projector assembly, a set of imaging optics optically coupled to the projector assembly, and an eyepiece optically coupled to the set of imaging optics. The eyepiece includes an incoupling interface. The artifact mitigation system also 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.

Claims

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 an incoupling interface; and

an artifact prevention element disposed between the set of imaging optics and the eyepiece, the artifact prevention element including;

a linear polarizer;

a first quarter waveplate disposed adjacent the linear polarizer;

a second quarter waveplate disposed between the linear polarizer and the set of imaging optics; and

a color select component disposed adjacent the first quarter waveplate.

2. The artifact mitigation system of claim 1, wherein the second quarter waveplate further comprises an achromatic quarter waveplate.

3. The artifact mitigation system of claim 1, wherein the second quarter waveplate is configured to convert a spatially defined portion of a light beam to linearly polarized light.

4. The artifact mitigation system of claim 1, wherein the linear polarizer is configured to pass a light beam characterized by a first linear polarization.

5. The artifact mitigation system of claim 4, wherein the first 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.

6. The artifact mitigation system of claim 5, wherein the color select component is configured to convert the light beam characterized by the elliptical polarization to wavelength dependent elliptically polarized light.

7. The artifact mitigation system of claim 6, wherein the incoupling interface is configured to reflect a return portion of the wavelength dependent elliptically polarized light, wherein the return portion of the wavelength dependent elliptically polarized light is characterized by an opposite handedness.

8. The artifact mitigation system of claim 7 wherein the color select component is configured to convert the return portion of the wavelength dependent elliptically polarized light characterized by the opposite handedness to an elliptically polarized return portion.

9. The artifact mitigation system of claim 8, wherein the first quarter waveplate is configured to convert the elliptically polarized return portion to a linearly polarized return portion.

10. The artifact mitigation system of claim 9, wherein the linear polarizer is configured to attenuate the linearly polarized return portion.

11. The artifact mitigation system of claim 10, wherein the linearly polarized return portion is perpendicular to the first linear polarization.

12. 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.

13. 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 second side and opposite to the third side.

14. The artifact mitigation system of claim 1, wherein the set of imaging optics are configured to form an image at the incoupling interface.

15. The artifact mitigation system of claim 1, wherein the incoupling interface further comprises at least one of polarizing films, wire grid polarizers, or dielectric stacked coatings.

16. 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 an incoupling interface and the set of imaging optics is configured to form an image at the incoupling interface; and

an artifact prevention element disposed between the set of imaging optics and the eyepiece, the artifact prevention element including;

a linear polarizer;

a first quarter waveplate disposed adjacent the linear polarizer; and

a color select component disposed adjacent the first quarter waveplate.

17. The artifact mitigation system of claim 16, wherein the artifact prevention element further includes an achromatic second quarter waveplate disposed between the linear polarizer and the set of imaging optics.

18. The artifact mitigation system of claim 17, wherein the achromatic second quarter waveplate is configured to convert a spatially defined portion of a light beam to linearly polarized light.

19. The artifact mitigation system of claim 16, wherein:

the linear polarizer is configured to pass a light beam characterized by a first linear polarization;

the first 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;

the color select component is configured to convert the light beam characterized by the elliptical polarization to wavelength dependent elliptically polarized light; and

the incoupling interface is configured to reflect a return portion of the wavelength dependent elliptically polarized light, wherein the return portion of the wavelength dependent elliptically polarized light is characterized by an opposite handedness.

20. The artifact mitigation system of claim 19 wherein the color select component is configured to convert the return portion of the wavelength dependent elliptically polarized light characterized by the opposite handedness to an elliptically polarized return portion.

21. The artifact mitigation system of claim 20, wherein the first quarter waveplate is configured to convert the elliptically polarized return portion to a linearly polarized return portion.

22. The artifact mitigation system of claim 21, wherein the linear polarizer is configured to attenuate the linearly polarized return portion.

23. The artifact mitigation system of claim 22, wherein the linearly polarized return portion is perpendicular to the first linear polarization.

24. The artifact mitigation system of claim 16, 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.

25. The artifact mitigation system of claim 16, 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 second side and opposite to the third side.

26. The artifact mitigation system of claim 16, wherein the incoupling interface further comprises at least one of polarizing films, wire grid polarizers, or dielectric stacked coatings.