Scanned Image Projection System Employing Intermediate Image Plane

• US 20130301097A1
• Filed: 05/08/2012
• Published: 11/14/2013
• Est. Priority Date: 05/08/2012
• Status: Active Grant

• Current Assignee: Microvision, Inc.
• Original Assignee: Microvision, Inc.
• Inventors: Hudman, Joshua M., DeJong, Christian Dean
• Granted Patent: US 8,711,458 B2
• Time in Patent Office: Days
• US Class Current: 359/212.1
• CPC Class Codes: G02B 26/101 with both horizontal and vertical deflecting means, e.g. raster or XY scanners colour television using laser beams scanning a display screen H04N9/3129
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

In imaging system (100), a spatial light modulator (101) is configured to produce images (102) by scanning a plurality light beams (104,105,106). A first optical element (107) is configured to cause the plurality of light beams to converge along an optical path (114) defined between the first optical element and the spatial light modulator. A second optical element (115) is disposed between the spatial light modulator and an output of the imaging system. The first optical element and the spatial light modulator are arranged such that an image plane (117) is created between the spatial light modulator and the second optical element. The second optical element is configured to collect the diverging light (118) from the image plane and collimate it. The second optical element then delivers the collimated light to a pupil (120) on the other side of the second optical element relative to the spatial light modulator.

Claims

1. An imaging system, comprising:

a spatial light modulator configured to produce images by scanning a plurality of light beams;

a first optical element configured to cause the plurality of light beams to converge along an optical path defined between the first optical element and the spatial light modulator; and

a second optical element disposed between the spatial light modulator and an output of the imaging system;

wherein the first optical element and the spatial light modulator are arranged such that an image plane exists between the spatial light modulator and the second optical element.

2. The imaging system of claim 1, wherein the first optical element comprises a powered optical element disposed at an output of a plurality of light sources.

3. The imaging system of claim 2, wherein the powered optical element comprises a plurality of powered optical elements.

4. The imaging system of claim 3, further comprising the plurality of light sources configured to produce the plurality of light beams, wherein the plurality of powered optical elements correspond to the plurality of light sources on a one to one basis.

5. The imaging system of claim 1, wherein the first optical element comprises a converging reflective element.

6. The imaging system of claim 5, further comprising:

a plurality of light sources configured to produce the plurality of light beams; and

one or more powered optical elements disposed at the output of the plurality of light sources.

7. The imaging system of claim 1, wherein the second optical element is configured to collect diverging light from the image plane and reimage the diverging light to one of a finite or infinite conjugate.

8. The imaging system of claim 7, further comprising a reflective element disposed on an opposite side of the second optical element relative to the spatial light modulator.

9. The imaging system of claim 8, wherein the second optical element is configured to cause the diverging light to converge along a second optical axis defined between the second optical element and the reflective element.

10. The imaging system of claim 9, wherein the second optical element is configured to cause the diverging light to converge to a pupil at or near the reflective element.

11. The imaging system of claim 8, wherein the reflective element comprises a second spatial light modulator.

12. The imaging system of claim 11, wherein:

the spatial light modulator is configured to scan along a first axis;

the second spatial light modulator is configured to scan along a second axis; and

the first axis and the second axis are substantially orthogonal.

13. The imaging system of claim 8, further comprising a third optical element disposed between the reflective element and the output of the imaging system, wherein the third optical element is configured to collect reflected light from the reflective element and create a pupil on a side of the third optical element disposed opposite the reflective element.

14. The imaging system of claim 1, wherein the second optical element comprises a doublet.

15. An imaging system, comprising:

a spatial light modulator configured to produce images by scanning a plurality of light beams as scanned light;

a first reflector; and

a second reflector;

wherein the first reflector is arranged so as to redirect the scanned light received from the spatial light modulator to the second reflector; and

wherein the second reflector is arranged so as to redirect the scanned light again to the spatial light modulator and cause the scanned light to converge along an optical axis defined between the second reflector and the spatial light modulator.

16. The imaging system of claim 15, wherein the spatial light modulator comprises a scanning mirror.

17. The imaging system of claim 15, wherein the second reflector comprises a concave mirror.

18. A method of producing images in an imaging system, comprising:

scanning a plurality of light beams with a spatial light modulator; and

causing the plurality of light beams to converge as the plurality of light beams travel to the spatial light modulator such that an image plane is created between the spatial light modulator and an optical element disposed between the spatial light modulator and an output of the imaging system.

19. The method of claim 18, further comprising:

collecting diverging light from the image plane; and

collimating the diverging light.

20. The method of claim 19, further comprising delivering the plurality of light beams to a reflective element such that an image pupil is defined at the reflective element.