Granted Patent B2

US 9,720,227 · App. 14/561,990 · Granted Aug 1, 2017

Abstract

Claims (61)

1. A compact optics module for a head mounted display including a digital light processor (“DLP”) image source comprising:

a polarized light source providing illumination light;

a flat reflective polarizer to reflect the illumination light toward the DLP image source and transmit image light, wherein the illumination light is provided at an angle to the DLP;

a quarter wave retarder to change the polarization state of the illumination light as it is reflected by the DLP image source thereby providing image light;

at least one light trap to absorb a portion of off-state image light;

a lens element to provide a viewable field of view of on-state image light in an image displayed by the DLP image source; and

a combiner to reflect the on-state image light toward a user's eye and provide a see-through view of a surrounding environment;

wherein the lens element includes at least one diffractive surface.

2. The compact optics module of claim 1 , wherein the flat reflective polarizer extends beyond a lens element surface.

3. The compact optics module of claim 1 , wherein the process of reflecting the illumination light and reflecting the on-state image light provides a multiply folded optical path that reduces the thickness and height of the compact optics module.

4. The compact optics module of claim 1 , further comprising a rear optical element selected from the group consisting of a protective plate and a prescriptive optic.

5. The compact optics module of claim 4 , wherein the protective plate is connected to a sidewall of a housing of the compact optics module.

6. The compact optics module of claim 1 , wherein the reflective polarizer reflects light of one polarization state and transmits light of the other polarization state.

7. The compact optics module of claim 1 , wherein the light trap is recessed into a wall of a housing of the compact optics module.

8. The compact optics module of claim 1 , wherein the light trap comprises a coating of black paint.

9. The compact optics module of claim 1 , wherein the light trap comprises at least one of a mask and a guard to block scattered light and prevent the light trap from being viewed adjacent to a displayed image.

10. The compact optics module of claim 1 , wherein the combiner includes a holographic mirror.

11. The compact optics module of claim 10 , wherein if a monochrome image is desired, a single wavelength reflection design for the holographic mirror is included on a surface of the combiner.

12. The compact optics module of claim 11 , wherein if a multiple color image is desired, a multiple wavelength holographic mirror is included on a surface of the combiner.

13. A compact optics module for a head mounted display including a digital light processor (“DLP”) image source comprising:

a polarized light source providing illumination light;

a flat reflective polarizer to reflect the illumination light toward the DLP image source and transmit image light, wherein the illumination light is provided at an angle to the DLP;

a quarter wave retarder to change the polarization state of the illumination light as it is reflected by the DLP image source thereby providing image light;

at least one light trap to absorb a portion of off-state image light;

a lens element to provide a viewable field of view of on-state image light in an image displayed by the DLP image source;

a combiner to reflect the on-state image light toward a user's eye and provide a see-through view of a surrounding environment; and

an absorptive polarizer adjacent to the lens element and oriented to absorb incident illumination light and transmit image light.

14. A compact optics module for a head mounted display including a digital light processor (“DLP”) image source comprising:

a polarized light source providing illumination light;

a flat reflective polarizer to reflect the illumination light toward the DLP image source and transmit image light, wherein the illumination light is provided at an angle to the DLP;

a quarter wave retarder to change the polarization state of the illumination light as it is reflected by the DLP image source thereby providing image light;

at least one light trap to absorb a portion of off-state image light;

a lens element to provide a viewable field of view of on-state image light in an image displayed by the DLP image source; and

a combiner to reflect the on-state image light toward a user's eye and provide a see-through view of a surrounding environment;

wherein the flat reflective polarizer is adjacent the lens element; and the compact optics module further comprises a second flat reflective polarizer that transmits illumination light and reflects image light toward the lens element.

15. The compact optics module of claim 4 , wherein the light source is positioned behind the second flat reflective polarizer.

16. A compact optics module for a head mounted display including a digital light processor (“DLP”) image source comprising:

a polarized light source providing illumination light;

a flat reflective polarizer to reflect the illumination light toward the DLP image source and transmit image light, wherein the illumination light is provided at an angle to the DLP;

a quarter wave retarder to change the polarization state of the illumination light as it is reflected by the DLP image source thereby providing image light;

at least one light trap to absorb a portion of off-state image light;

a lens element to provide a viewable field of view of on-state image light in an image displayed by the DLP image source; and

a combiner to reflect the on-state image light toward a user's eye and provide a see-through view of a surrounding environment;

wherein the see-through view of the surrounding environment includes unpolarized light and the combiner transmits over 50 % of the unpolarized light.

17. A compact optics module for a head mounted display including a digital light processor (“DLP”) image source comprising:

a polarized light source providing illumination light;

a flat reflective polarizer to reflect the illumination light toward the DLP image source and transmit image light, wherein the illumination light is provided at an angle to the DLP;

a quarter wave retarder to change the polarization state of the illumination light as it is reflected by the DLP image source thereby providing image light;

at least one light trap to absorb a portion of off-state image light;

a lens element to provide a viewable field of view of on-state image light in an image displayed by the DLP image source; and

a combiner to reflect the on-state image light toward a user's eye and provide a see-through view of a surrounding environment;

wherein the combiner is a partial mirror.

18. A compact optics module for a head mounted display including a digital light processor (“DLP”) image source comprising:

a polarized light source providing illumination light;

a flat reflective polarizer to reflect the illumination light toward the DLP image source and transmit image light, wherein the illumination light is provided at an angle to the DLP;

a quarter wave retarder to change the polarization state of the illumination light as it is reflected by the DLP image source thereby providing image light;

at least one light trap to absorb a portion of off-state image light;

a lens element to provide a viewable field of view of on-state image light in an image displayed by the DLP image source; and

a combiner to reflect the on-state image light toward a user's eye and provide a see-through view of a surrounding environment;

wherein the combiner is a notch mirror.

19. The compact optics module of claim 18 , wherein the notch mirror is a tristimulus notch mirror.

Assignments (9)