Display system having a plurality of light pipes for a plurality of light emitters

• US 10,775,545 B2
• Filed: 02/24/2017
• Issued: 09/15/2020
• Est. Priority Date: 02/26/2016
• Status: Active Grant

• Current Assignee: Magic Leap, Inc.
• Original Assignee: Magic Leap, Inc.
• Inventors: Curtis, Kevin, Hall, Heidi Leising, St. Hilaire, Pierre, Tinch, David
• Primary Examiner(s): Thomas, Brandi N
• Application Number:
  US15/442,564
• Publication Number:
  US 20170248750A1
• Time in Patent Office: 1,299 Days
• Field of Search: 359619-633
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 2027/0114 comprising dichroic elements
• CPC Class Codes: G02B 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0194 with combiner of laminated type, for optical or mechanical aspects
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/141 using dichroic mirrors
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre
• CPC Class Codes: G02B 6/0025 Diffusing sheet or layer; Prismatic sheet or layer
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• 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 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0076 Stacked arrangements of multiple light guides of the same or different cross-sectional area
• CPC Class Codes: G02B 6/34 utilising prism or grating G02B6/293 takes precedence

Abstract

In some embodiments, a display system is provided. The display system comprises a plurality of light pipes and a plurality of light sources configured to emit light into the light pipes. The display system also comprises a spatial light modulator configured to modulate light received from the light pipes to form images. The display system may also comprise one or more waveguides configured to receive modulated light from the spatial light modulator and to relay that light to a viewer.

Claims

1. A display system comprising:

a plurality of light pipes;

a plurality of light sources configured to emit light into the light pipes; and

a spatial light modulator configured to modulate light received from the light pipes to form a plurality of component color images,

wherein each of the light pipes comprises first and second opposing ends and a sidewall extending from the first end to the second end,

wherein the first end comprises a light input surface configured to receive light from an associated light source,

wherein the second end comprises a light output surface configured to output light to the spatial light modulator,

wherein each light pipe is oriented to localize outputted light on a different location on the spatial light modulator than other light pipes, and

wherein the display system is configured to form different ones of the plurality of component color images at the different locations receiving light from the light pipes.

2. The display system of claim 1, wherein the light output surface of each of the light pipes has a larger area than the light input surface of the respective light pipe.

3. The display system of claim 1, wherein at least one of the light pipes are proximate to and configured to receive light from a corresponding two or more of the light sources through the light input surface of the at least one of the light pipes.

4. The display system of claim 3, wherein a first light pipe of the plurality of light pipes has a first height between a light input surface and a light output surface of the first light pipe, wherein a second light pipe of the plurality of light pipes has a second height between a light input surface and a light output surface of the second light pipe, wherein the first height is different from the second height.

5. The display system of claim 1, wherein the light input surface of each of the light pipes has a first geometry and the associated light output source has a second geometry different from the first geometry.

6. The display system of claim 5, wherein the plurality of light pipes each have an associated inner width.

7. The display system of claim 6, wherein the inner width varies throughout a length of a light pipe.

8. The display system of claim 3, wherein each of the corresponding two or more of the light sources are configured to emit light of different ranges of wavelengths.

9. The display system of claim 3, wherein the at least one of the light pipes comprises a light redirecting feature at the light input end.

10. The display system of claim 9, wherein the light redirecting feature comprises one or more of a diffuser, a grating, and a prism.

11. The display system of claim 3, further comprising:

a stack of waveguides, each waveguide comprising a light incoupling optical element configured to receive light from the spatial light modulator,

wherein the light incoupling optical element of one or more first waveguides is spatially offset from the light incoupling optical element of two or more other waveguides, as seen in a plan view viewed from a direction along the axis of propagation of the light into the stack, and

wherein the light incoupling optical elements of at least two of the two or more other waveguides at least partially overlap, as seen in the plan view.

12. The display system of claim 11, wherein the light incoupling optical elements of at least two of the two or more other waveguides are configured to incouple light from different ones of the corresponding two or more of the light sources,

wherein the light incoupling optical elements of at least two of the two or more other waveguides are laterally shifted relative to one another such that none of the light incoupling optical elements of at least two of the two or more other waveguides are centered on a light pipe transmitting light to be incoupled into the two or more other waveguides.

13. The display system of claim 12, wherein each waveguide of the stack of waveguides comprises a light outcoupling optical element configured to output incoupled light with different amounts of divergence in comparison to one or more other waveguides of the stack of waveguides.

14. The display system of claim 1, wherein two or more of the light pipes are part of a unitary piece of optically transmissive material.

15. The display system of claim 14, wherein all of the plurality of light pipes are part of the unitary piece of optically transmissive material.

16. The display system of claim 1, wherein one or more light sources are configured to emit light of different wavelengths than other light sources.

17. The display system of claim 16, wherein the light sources form groups of light sources, wherein each group emits light of a different range of wavelengths.

18. The display system of claim 17, wherein the light sources form three groups of light sources, wherein a first of the groups emit red light, wherein a second of the groups emit green light, and wherein a third of the groups emit blue light.

19. The display system of claim 16, wherein one or more light pipes have different heights than other light pipes.

20. The display system of claim 19, wherein the heights of the light pipes varies depending upon the wavelengths of light emitted by the light source corresponding to the light pipe.

21. The display system of claim 20, wherein the heights of the light pipes increase as an average wavelength of light emitted by a corresponding light source increases.

22. The display system of claim 1, wherein the spatial light modulator comprises a liquid crystal display (LCD) or a digital light processing (DLP) display.

23. The display system of claim 1, further comprising a diffuser at the light output end of the light pipe.

24. The display system of claim 1, further comprising baffling configured to block light leakage between each of the light pipes.

25. The display system of claim 1, wherein one or more of the light pipes have a different maximum width than other light pipes.

26. The display system of claim 1, wherein the light sources comprise a blue light emitter and further comprising a color-changing film comprising:

one or more of a phosphor and quantum dot configured to receive blue light from and emit light of another color.

27. The display system of claim 26, wherein the color-changing film is on the surface of one or more of the light pipes.

28. The display system of claim 1, further comprising a stack of waveguides, each waveguide comprising a light incoupling optical element configured to receive light from the spatial light modulator.

29. The display system of claim 28, wherein the light incoupling optical element of each waveguide is spatially offset from the light incoupling optical element of other waveguides, as seen in a plan view viewed from a direction along the axis of propagation of the light into the stack.

30. The display system of claim 29, wherein, as seen in a plan view, a spatial arrangement of light output ends of the light pipes corresponds one-to-one with a spatial arrangement of the light incoupling optical elements.

31. The display system of claim 28, wherein each waveguide of the stack of waveguides comprises a light outcoupling optical element configured to output light with different amounts of divergence in comparison to one or more of the other waveguides of the stack of waveguides.

32. The display system of claim 1, wherein the light pipes comprise plastic or glass.

33. The display system of claim 1, further comprising a prism interposed between a light source and a light pipe.

34. A display system comprising:

a partially transmissive reflector;

a first light source;

a first light pipe proximate to and configured to;

receive light from the first light source; and

direct the light from the first light source to the reflector in a first direction;

a second light source;

a second light pipe proximate to and configured to;

receive light from the second light source; and

direct the light from the second light source to the reflector in a second direction,

wherein the partially transmissive reflector is configured to;

transmit light from the first light source; and

reflect light from the second light source,

wherein each of the light pipes comprises first and second opposing ends and a sidewall extending from the first end to the second end,

wherein the first end comprises a light input surface configured to receive light from an associated light source,

wherein the second end comprises a light output surface configured to output light to the spatial light modulator, and

wherein each light pipe is oriented to localize outputted light on a different location on the spatial light modulator than other light pipes.

35. The display system of claim 34, wherein light from the first light source has a different range of wavelengths than light from the second light source.

36. The display system of claim 34, wherein the partially transmissive reflector is a dichroic mirror.