Transparent waveguide display for tiling a display having plural optical powers using overlapping and offset FOV tiles

Patent metadata

Field	Value
Publication number	US-11448937-B2
Application number	US-202117153588-A
Country	US
Kind code	B2
Filing date	Jan 20, 2021
Priority date	Nov 16, 2012
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

One embodiment provides an apparatus for displaying an image comprising: a first optical substrate comprising at least one waveguide layer configured to propagate light in a first direction, wherein the at least one waveguide layer of the first optical substrate comprises at least one grating lamina configured to extract the light from the first substrate along the first direction; and a second optical substrate comprising at least one waveguide layer configured to propagate the light in a second direction, wherein the at least one waveguide layer of the second optical substrate comprises at least one grating lamina configured to extract light from the second substrate along the second direction; wherein the at least one grating lamina of at least one of the first and second optical substrates comprises an SBG in a passive mode.

First claim

What is claimed:

1. An apparatus for displaying an image comprising:
at least one source of image modulated collimated light over an angular range;
at least one waveguide layer comprising gratings for:
coupling said light into a waveguide path;

wherein said gratings comprise a first element and a second element for forming an exit pupil configured to view a tiled field of view (FOV) displaying the image modulated light;
wherein each element diffracts light out of the waveguide towards the exit pupil and provides a beam expansion in a first direction;
wherein the first element and the second element are partially overlapping and laterally offset;
wherein the tiled FOV comprises a first FOV tile and a second FOV tile;
wherein the first FOV tile and the second FOV tile are partially overlapping and laterally offset;
wherein the source of image modulated collimated light is configured to be electronically switchable between displaying first image data for projection within the first FOV tile and displaying second image data for projecting within the second FOV tile;
wherein the first element has a first optical power for forming the first FOV tile at a first distance from the exit pupil;
wherein the second element has a second optical power for forming the second FOV tile at a second distance from the exit pupil; and
wherein the first distance and the second distance are different.

2. The apparatus of claim 1 , wherein said gratings are selected from a Bragg grating, a SBG, a HPDLC grating, a uniform modulation grating, a reverse mode HPDLC grating and a surface relief grating.

3. The apparatus of claim 1 , comprising a plurality of waveguide layers,
wherein when the plurality of waveguide layers comprises three waveguide layers, the three waveguide layers are configured to propagate red, green, and blue light, and
wherein when the plurality of waveguide layers comprises two waveguide layers, the two waveguide layers are configured to propagate red light and mixed blue and green light.

4. The apparatus of claim 1 , wherein at least one of said gratings comprises at least one characteristic from the group consisting of: rolled k-vectors; multiplexing of at least two different grating prescriptions; an overlap with at least one other grating; and a thickness varying across at least one waveguide.

5. A vehicle or aircraft head up display (HUD) comprising the apparatus of claim 1 , wherein the device is a part of at least one of HMD, HUD, or HDD.

6. The vehicle or aircraft HUD of claim 5 , wherein said at least one waveguide layer further comprises at least one structure selected from the group consisting of:
a plurality of different field of view tiles having different angular ranges,
at least one grating structure for providing separate exit pupils for a driver and a passenger,
an image sensor for capturing images of one or more objects external to said vehicle and in signal communication with the at least one source such that the image modulated collimated light contains information concerning the one or more objects,
a reflecting layer overlaying at least one grating,
a windscreen and wherein the at least one waveguide is combined with or integrated within the windscreen,
a windscreen and wherein the at least one waveguide is a flexible layer bonded onto an inner or an outer surface of the windscreen, and
at least one waveguide curved in at least one plane.

7. The vehicle or aircraft HUD of claim 6 , wherein said at least one source is configured to provide images of objects external to said vehicle captured by the imaging sensor.

8. The apparatus of claim 1 , wherein said at least one source comprises a microdisplay in optical communication with a collimation optic.

9. The apparatus of claim 1 , further comprising a source of structured infrared radiation in optical communication with an infrared detector.

10. The apparatus of claim 9 , wherein the source of the structured infrared radiation and the infrared detector are configured to perform at least one function selected from the group consisting of: gesture detection, detection of objects in the vicinity of the display, and eye tracking.

11. The apparatus of claim 1 , wherein said at least one source of image modulated collimated light comprises a two-dimensional array of grating lenses, wherein each of the grating lenses diffracts incident collimated light into a total internal reflection (TIR) path within the at least one waveguide layer.

12. The apparatus of claim 1 , wherein the at least one source is at least one light emitting diode (LED) having a peak emission wavelength and further comprising a plurality of gratings with peak diffraction efficiency vs. wavelength characteristics shifted by small increments from said peak emission wavelength such that the diffraction efficiency loss in a spectral bandwidth of the at least one LED is compensated.

13. The apparatus of claim 1 , wherein said gratings further comprise an expansion grating configured to provide a beam expansion in a second direction orthogonal to the first direction.

Assignees

• Digilens Inc
• Rockwell Collins Inc

Inventors

• Brown Robert D
• Grant Alastair John
• Hendrick Wyatt L
• Popovich Milan Momcilo
• Stanley James H
• Waldern Jonathan David

Classifications

• G03H2260/34

  Non uniform thickness · CPC title

• G02F1/29 Primary

  for the control of the position or the direction of light beams, i.e. deflection · CPC title

• G02B27/0172

  characterised by optical features · CPC title

• G02B2027/0118

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

• G02B27/4272

  having plural diffractive elements positioned sequentially along the optical path · CPC title