Laser illumination scanning

• US 9,297,996 B2
• Filed: 02/15/2012
• Issued: 03/29/2016
• Est. Priority Date: 02/15/2012
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Bohn, David D., Fleck, Rod G.
• Primary Examiner(s): Harrington, Alicia M
• Application Number:
  US13/397,495
• Publication Number:
  US 20130208362A1
• Time in Patent Office: 1,504 Days
• Field of Search: 359630-634, 359/629, 359/636, 359/638, 345 7- 9
• US Class Current: 1/1
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 26/00 Optical devices or arrangements for the control of light using movable or deformable optical elements control of light by modification of the optical properties of the media of the elements involved therein G02F1/00
• CPC Class Codes: G02B 27/017 Head mounted

Abstract

In embodiments of laser illumination scanning, an imaging unit includes a linear array of spatial light modulators that direct light in a direction perpendicular to an imaging scan direction. The lasers each emit the light through a diffractive optic that uniformly illuminates the spatial light modulators, and a scanning mirror then scans the spatial light modulators to generate a two-dimensional image for display. The lasers can include red, green, and blue lasers for RGB illumination of the spatial light modulators, which can be implemented as reflective liquid crystal on silicon (LCOS), transmissive LCOS, or as micro-electro-mechanical systems (MEMS) mirrors.

Claims

1. An imaging unit, comprising:

a linear array of spatial light modulators configured to direct light in a direction perpendicular to an imaging scan direction;

lasers configured to emit the light through a diffractive optic, creating a structured light pattern that uniformly illuminates the spatial light modulators;

a scanning mirror configured to scan the light reflected by the spatial light modulators to generate a two-dimensional image for display; and

a polarizing beam-splitter positioned between the diffractive optic, the linear array of spatial light modulators, and the scanning mirror, the polarizing beam-splitter configured to reflect the structured light pattern from the diffractive optic to the linear array of spatial light modulators and to the scanning mirror.

2. An imaging unit as recited in claim 1, wherein the lasers include a red laser, a green laser, and a blue laser for red, green, and blue (RGB) illumination of the spatial light modulators.

3. An imaging unit as recited in claim 1, wherein the spatial light modulators comprise one of reflective liquid crystal on silicon (LCOS) or transmissive LCOS.

4. An imaging unit as recited in claim 1, wherein the spatial light modulators comprise micro-electro-mechanical systems (MEMS) mirrors.

5. An imaging unit as recited in claim 1, wherein the scanning mirror is a single axis mirror configured to scan the linear array of the spatial light modulators in one dimension to generate the two-dimensional image for display.

6. An imaging unit as recited in claim 1, wherein a field of view in the imaging scan direction corresponds to a range of motion of the scanning mirror.

7. An imaging unit as recited in claim 1, wherein a field of view in the direction perpendicular to the imaging scan direction corresponds to a length of the linear array of the spatial light modulators and a focal length of projection optics of the imaging unit.

8. A method, comprising:

emitting light with lasers that illuminate an array of spatial light modulators;

dispersing the light that is emitted from a laser with a diffractive optic, creating a structured light pattern that uniformly illuminates the spatial light modulators;

reflecting the structured light pattern from the diffractive optic to a scanning mirror and to the array of spatial light modulators;

directing the light from the array of spatial light modulators in a direction perpendicular to an imaging scan direction; and

scanning the light reflected by the spatial light modulators with the scanning mirror to generate a two dimensional image for display.

9. A method as recited in claim 8, wherein the lasers include a red laser, a green laser, and a blue laser for red, green, and blue (RGB) illumination of the spatial light modulators.

10. A method as recited in claim 8, wherein the spatial light modulators comprise one of reflective liquid crystal on silicon (LCOS) or transmissive LCOS.

11. A method as recited in claim 8, wherein the spatial light modulators comprise micro-electro-mechanical systems (MEMS) mirrors.

12. A method as recited in claim 8, wherein the scanning mirror is a single axis mirror that scans the linear array of the spatial light modulators in one dimension to generate the two-dimensional image for display.

13. A method as recited in claim 8, wherein a field of view in the imaging scan direction corresponds to a range of motion of the scanning mirror.

14. A method as recited in claim 8, wherein a field of view in the direction perpendicular to the imaging scan direction corresponds to a length of the linear array of the spatial light modulators and a focal length of projection optics of the imaging unit.

15. A wearable display device, comprising:

left and right display lens systems configured for augmented reality imaging;

an eye-tracking system configured to track user eye position;

left and right imaging units of the respective left and right display lens systems configured to generate an augmented reality image, the left and right imaging units each comprising;

a linear array of spatial light modulators configured to direct light in a direction perpendicular to an imaging scan direction;

lasers configured to emit the light through a diffractive optic, creating a structured light pattern that uniformly illuminates the spatial light modulators and the emitted light configured as an illumination source for the eye-tracking system;

a scanning mirror configured to scan the light reflected by the spatial light modulators to generate a two-dimensional image for display; and

a polarizing beam-splitter positioned between the diffractive optic, the linear array of spatial light modulators, and the scanning mirror, the polarizing beam-splitter configured to reflect the structured light pattern from the diffractive optic to the linear array of spatial light modulators and to the scanning mirror.

16. A wearable display device as recited in claim 15, wherein the lasers include a red laser, a green laser, and a blue laser for red, green, and blue (RGB) illumination of the spatial light modulators.

17. A wearable display device as recited in claim 15, wherein the spatial light modulators comprise one of reflective liquid crystal on silicon (LCOS) or transmissive LCOS.

18. A wearable display device as recited in claim 15, wherein the spatial light modulators comprise micro-electro-mechanical systems (MEMS) mirrors.

19. A wearable display device as recited in claim 15, wherein the scanning mirror is a single axis mirror configured to scan the linear array of the spatial light modulators in one dimension to generate the two-dimensional image for display.

20. A wearable display device as recited in claim 15, wherein:

a field of view in the imaging scan direction corresponds to a range of motion of the scanning mirror; and

the field of view in the direction perpendicular to the imaging scan direction corresponds to a length of the linear array of the spatial light modulators and a focal length of projection optics of the imaging unit.