Head up display (HUD) using a bent waveguide assembly

Patent metadata

Field	Value
Publication number	US-9507150-B1
Application number	US-201313892026-A
Country	US
Kind code	B1
Filing date	May 10, 2013
Priority date	Sep 30, 2011
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

The head up display provides light from an image source. The head up display includes a waveguide assembly comprising a first waveguide for disposition at an angle with respect to a top surface of a glare shield and a second waveguide disposed at an angle with respect to the first waveguide. The first waveguide has a first diffractive coupler at a first end and a second waveguide has a second diffractive coupler at a second end. The first waveguide is positioned as a combiner and allows viewing of an outside scene and information from the image source. At least part of the first waveguide is disposed beneath the top surface of a glare shield.

First claim

What is claimed is:

1. A head up display for providing light from an image source, the head up display for disposition in a vehicle having a glare shield disposed above vehicle instrumentation, the glare shield having a top surface, the head up display comprising:
a waveguide assembly comprising a first waveguide disposed at an angle with respect to the top surface of the glare shield and a second waveguide disposed at an angle with respect to the first waveguide, the first waveguide having a first diffractive coupler at a first end of the first waveguide and the second waveguide having a second diffractive coupler at a second end of the second waveguide, and the first waveguide being positioned as a combiner and allowing viewing of an outside scene and information from the image source, wherein at least part of the first waveguide is configured to be disposed beneath the top surface of the glare shield, wherein the second waveguide is disposed entirely below the top surface and a first end of the second waveguide provides light to a second end of the first waveguide beneath the top surface of the glare shield, wherein the second waveguide is configured so that the light travels from the second end of the first waveguide to the first end of the second waveguide by total internal reflection, wherein the first waveguide and the second waveguide are not a single waveguide and the first waveguide is tilted with respect to the second waveguide, wherein the second diffractive coupler is provided at a planar main surface of the second waveguide, the planar main surface being approximately parallel to the glare shield.

2. The head up display of claim 1 , wherein the first and second diffractive couplers are diffraction gratings.

3. The head up display of claim 2 , wherein the first and second diffractive couplers are surface relief gratings.

4. The head up display of claim 3 , wherein the first and second diffractive couplers are holographic diffractive elements and the vehicle is an aircraft.

5. The head up display of claim 1 , wherein the image source is part of a projector disposed entirely below the top surface of the glare shield, wherein the projector is disposed below the second waveguide at the second end of the second waveguide, wherein the second waveguide is disposed substantially parallel to the top surface of the glare shield.

6. The head up display of claim 1 , wherein the first waveguide is disposed at an obtuse degree angle with respect to the second waveguide.

7. The head up display of claim 5 , wherein light from the image source enters the second waveguide via the second diffractive coupler at the second end vertically with respect to gravity at the planar main surface, the planar main surface being a bottom surface and the bottom surface is horizontal with respect to gravity.

8. The head up display of claim 7 , wherein second waveguide is at an obtuse angle with respect to the first waveguide.

9. The head up display of claim 1 , wherein the light from a primary ray enters the first waveguide at a 90° angle from a surface of the first waveguide and leaves the second waveguide at a 90° angle from a surface of the second waveguide.

10. The head up display of claim 1 , wherein the second diffractive coupler has a greater efficiency than the first diffractive coupler.

11. A cockpit comprising:
a glare shield for shielding aircraft instrumentation having a top surface; and
a head up display comprising:
a collimator; and
a combiner assembly, wherein the combiner assembly includes a first waveguide positioned to receive light from the collimator, wherein the combiner assembly includes a second waveguide disposed as a combiner, the second waveguide being disposed at an angle with respect to the first waveguide, the second waveguide being disposed at least partially above a top surface of the glare shield, the first waveguide having a first waveguide end disposed next to a second waveguide end of the second waveguide beneath the top surface of the glare shield, the first waveguide and the collimator being entirely disposed beneath the top surface of the glare shield, wherein the collimator is entirely disposed beneath a main planar surface of the first waveguide, wherein the main planar surface includes an input coupler configured to receive light from the collimator and the main planar surface is disposed approximately parallel to the top surface of the glare shield.

12. The cockpit of claim 11 , wherein image source includes a laser or LED illuminator providing light through a beam splitter.

13. The cockpit of claim 11 , wherein an output diffraction grating for the combiner is disposed above the glare shield and the second waveguide is not parallel to a top surface of the glare shield.

14. The cockpit of claim 11 , wherein the first waveguide includes a diffraction grating.

Assignees

• Stratton Eric P
• Buchholz Christopher M
• Brown Robert D
• Keith Christopher A
• Stanley James H
• Rockwell Collins Inc

Inventors

• Stratton Eric P
• Buchholz Christopher M
• Brown Robert D
• Keith Christopher A
• Stanley James H

Classifications

• G02F1/163

  Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor · CPC title

• G02B6/0016

  Grooves, prisms, gratings, scattering particles or rough surfaces · CPC title

• G02B2027/0118

  comprising devices for improving the contrast of the display / brillance control visibility · CPC title

• G02B2027/0125

  Field-of-view increase by wavefront division · CPC title

• G02B2027/0145

  creating an intermediate image · CPC title