Image generator having an improved illumination system

• US 20020027779A1
• Filed: 07/23/2001
• Published: 03/07/2002
• Est. Priority Date: 07/02/1999
• Status: Active Grant

• Current Assignee: Compound Photonics Limited
• Original Assignee: Zight Corporation (Three-Five Systems, Inc.)
• Inventors: Cassarly, William J., Schuck, Miller H. III
• Granted Patent: US 6,488,389 B2
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00

Abstract

The invention provides an illumination system for a head-mounted display. The illumination system includes a plurality of illuminators which irradiate light over an area. The area has a central region where the light has a selective intensity, and outer regions on opposing sides of the central regions where the light has higher intensities than the selective intensity.

Claims

1. An illumination system for a head-mounted display, which includes:

a plurality of illuminators radiating light over an area having a central region where the light has a selected intensity, and outer regions, on opposing sides of the central region, where the light has higher intensities than the selected intensity.

2. An illumination system according to claim 1 wherein the intensity of the light at one of the outer regions is substantially equal to the intensity of the light at the other outer region.

3. An illumination system according to claim 1 which includes at least a first illuminator and a second illuminator, the first illuminator creating light having a first color and the second illuminator creating light having a second color which is different from the first color, the light from the first illuminator and the second illuminator being radiated over the area.

4. An illumination system according to claim 3 which includes at least a third illuminator and a fourth illuminator, the third illuminator creating light having the first color and the fourth illuminator creating light having the second color, the light from the first, second, third, and fourth illuminators being radiated over the area.

5. An illumination system according to claim 4 wherein the first and third illuminators are spaced by a distance which substantially equals a distance by which the second and fourth illuminators are spaced.

6. An illumination system according to claim 1 which includes at least a first illuminator which creates red light, a second illuminator which creates green light, and a third illuminator which creates blue light, the light from the first, second, and third illuminators being radiated over the area.

7. An illumination system according to claim 6 which includes at least a fourth illuminator which creates red light, a fifth illuminator which creates green light, and a sixth illuminator which creates blue light, the light from the first, second, third, fourth, fifth and sixth illuminators being radiated over the area.

8. An illumination system according to any one of claims 1 to 7 which includes a reflective surface from which the light reflects before passing through the area.

9. An illumination system according to claim 8 wherein the illuminators are located in a first group and a second group, the light passing through a space between the first and second groups after being reflected from the reflective surface and before passing through the area, the illuminators of each group including at least a red illuminator, a green illuminator, and a blue illuminator.

10. An illumination system according to claim 9 wherein each illuminator is spaced by a respective distance from a center of the space, the respective distances being substantially equal.

11. An illumination system for a head-mounted display, which includes:

a housing defining an enclosure having a reflective inner surface, the housing having an opening out of the enclosure;

one illuminator located on a first side of the opening in a position wherein light radiated from that illuminator reflects off the reflective surface at least once and then passes through the opening out of the enclosure; and

another illuminator located on a second side of the opening in a position wherein light radiated from that illuminator reflects off the reflective surface at least once and then passes through the opening and out of the enclosure.

12. An illumination system according to claim 11 wherein the illuminators are located around the opening.

13. An illumination system according to claim 12 wherein the light leaving the opening has an intensity distribution over an area wherein the distribution of the intensity on one side of the area is substantially a mirror image of the distribution of the intensity on an opposing side of the area.

14. An illumination system according to claim 11 which includes:

a first group of illuminators, on the first side of the opening, comprising a first illuminator, a second illuminator, and a third illuminator, at least one of the first, second, and third illuminators creating red light, one creating green light, and one creating blue light; and

a second group of illuminators, on the second side of the opening, comprising a fourth illuminator, a fifth illuminator, and a sixth illuminator, at least one of the fourth, fifth, and sixth illuminators creating red light, one creating green light, and one creating blue light.

15. An illumination system according to claim 14 wherein the first, second, third, fourth, fifth, and sixth illuminators are in each located by a respective distance from a center of the opening, the distances being substantially equal.

18. An image generator according to claim 17 wherein the lens has an f-number which is less than 1.

16. An illumination system for a head-mounted display, which includes:

a first illuminator which creates red light;

a second illuminator which creates green light;

a third illuminator which creates blue light, the first second and third illuminators being located in a first group;

a fourth illuminator which creates red light;

a fifth illuminator which creates green light;

a sixth illuminator which creates blue light, the fourth, fifth, and sixth illuminators being located in a second group, the illuminators being located in a circle, the first and fourth illuminators being spaced by a distance which is substantially the same as the distance by which the second and fifth illuminators are spaced, which is substantially the same as a distance by which the third and sixth illuminators are spaced;

a reflective surface from which light from the first, second, third, fourth, fifth, and sixth illuminators reflects, whereafter the light passes through a space between the first and second groups, whereafter the light passes through an area over which the light from the first, second, third, fourth, fifth, and sixth illuminators is radiated, the area having a central region where the light has a selected intensity, and the outer regions, on opposing sides of the central region, where the light has higher intensities than the selected intensity, the intensity of the light at one of the outer regions is substantially equal to the intensity of the light at the other outer region, and light having an intensity distribution in the one outer region which is substantially a mirror image of an intensity distribution of the light in the other outer region.

17. An image generator for a head-mounted display, which includes:

a plurality of illuminators radiating light over an area having a central region where the light has a selected intensity, and outer regions, on opposing sides of the central region, where the light has higher intensities than the selected intensity;

a lens located in a position wherein the light passes therethrough; and

a display which the light illuminates after leaving the lens.

19. A method of generating an image in a head-mounted display, comprising:

creating light, utilizing a plurality of illuminators, over an area having a central region where the light has a selected intensity, and outer regions, on opposing sides of the central region, where the light has higher intensities than the selected intensity whereafter the light passes through a lens and then illuminates a display.