Optical device with tilt and power microlenses

• US 7,762,683 B2
• Filed: 02/23/2007
• Issued: 07/27/2010
• Est. Priority Date: 02/23/2007
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Williams, Darin S.
• Primary Examiner(s): ALSOMIRI, ISAM A
• Application Number:
  US11/678,229
• Publication Number:
  US 20080204731A1
• Time in Patent Office: 1,250 Days
• Field of Search: 356/4.01, 362/244, 362/330, 362/329, 362/620, 362/619, 362/606, 362/607, 362223-225
• US Class Current: 362/244
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 3/005 arranged along a single direction only, e.g. lenticular sheets G02B3/0043 takes precedence

Abstract

A microlens array includes plural powered microlenses or microlens elements for tilting different light-emitting elements or portions of a light-emitting device. Each microlens or microlens element both has optical power, and adjusts the tilt of the wavefront so that in combination the individual microlenses act like a more complex multiple-element optic where each element shifts light from only a portion of the light-emitting device. Such an optical device may be incorporated into eyewear for projecting subtitles or other information above or below a far-away image, such as on a movie screen. Another potential use of the microlens array is for use in a heads-up display. Still another potential use for the microlens array to provide soft focusing of emitted laser light to achieve a target light spot of a desired diameter.

Claims

1. An optical device comprising:

a light-emitting device containing multiple light-emitting elements; and

plural microlens elements having optical power, operatively coupled to the light-emitting device such that the microlens elements individually differently tilt wavefronts of light emitted by different of the light-emitting elements;

wherein the microlens elements tilt the light of the light-emitting elements substantially toward a single focal point.

2. The optical device of claim 1, wherein the microlens elements are parts of a single piece of material.

3. The optical device of claim 2, wherein the single piece of material is a stamped plastic piece.

4. The optical device of claim 1, wherein the microlens elements are refractive elements.

5. The optical device of claim 1, wherein the microlens elements shift apparent focus of the light from the light-emitting device.

6. The optical device of claim 5, wherein the microlens elements shift the apparent focus substantially to infinity.

7. The optical device of claim 1, wherein the light-emitting device and the microlens elements are incorporated into a head-mounted device.

8. The optical device of claim 1, wherein the light-emitting device and the microlens elements are parts of a heads-up display device.

9. The optical device of claim 1, wherein the light-emitting device is a light emitting diode display.

10. The optical device of claim 1, wherein the microlens elements collimate portions of the light emitted by different of the light-emitting elements.

11. The optical device of claim 10, wherein the microlens elements tilt and collimate the light from each of light-emitting elements, sending the light from each of the light-emitting elements on its own unique collimated path.

12. The optical device of claim 11, wherein the microlens elements alter the wavefronts from curved wavefronts to substantially straight wavefronts.

13. The optical device of claim 1, wherein in combination the microlens elements act as a more complex multiple-element optic.

14. The optical device of claim 1, wherein the microlens elements alter the wavefronts from curved wavefronts to substantially straight wavefronts.

15. A method of optical display, the method comprising:

emitting light from multiple light-emitting elements of a light-emitting device; and

individually differently tilting wavefronts of the light emitted by different of the light-emitting elements using plural microlens elements having optical power;

wherein the tilting includes tilting the light of the light-emitting elements substantially toward a single focal point.

16. The method of claim 15, wherein the tilting includes shifting apparent focus of the light substantially to infinity.

17. The method of claim 15, wherein the tilting includes the microlens elements collimating portions of the light emitted by different of the light-emitting elements.

18. The method of claim 15, wherein the tilting includes altering the wavefronts from curved wavefronts to substantially straight wavefronts.