Free space multiple laser diode modules

Patent metadata

Field	Value
Publication number	US-11300788-B2
Application number	US-201816168694-A
Country	US
Kind code	B2
Filing date	Oct 23, 2018
Priority date	Oct 23, 2017
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

Systems, devices, and methods for optical engines and laser projectors that are well-suited for use in wearable heads-up displays (WHUDs) are described. Generally, the optical engines of the present disclosure integrate a plurality of laser diodes (e.g., 3 laser diodes, 4 laser diodes) within a single, hermetically sealed, encapsulated package. Such optical engines may have various advantages over existing designs including, for example, smaller volumes, better manufacturability, faster modulation speed, etc. WHUDs that employ such optical engines and laser projectors are also described.

First claim

The invention claimed is:

1. A wearable heads-up display (WHUD), comprising:
a support structure that in use is worn on a head of a user;
a laser projector carried by the support structure, the laser projector comprising:
an optical engine, comprising:
a base substrate;
a plurality of chip submounts bonded to the base substrate;
a plurality of laser diodes, each of the plurality of laser diodes bonded to a corresponding one of the plurality of chip submounts;
at least one laser diode driver circuit bonded to the base substrate, the at least one laser diode driver circuit operatively coupled to the plurality of laser diodes to selectively drive current to the plurality of laser diodes;
an optical director element comprising a plurality of faces, wherein a single face of the plurality of faces is shared between the plurality of laser diodes and configured to receive laser light emitted from each laser diode of the plurality of laser diodes;
a plurality of collimation lenses configured to receive the laser light from the single face of the optical director element;
a beam combiner configured to receive and combine the laser light from the plurality of collimation lenses into an aggregated laser light beam;
a cap comprising at least one wall and at least one optical window that together define an interior volume sized and dimensioned to receive at least the plurality of chip submounts and the plurality of laser diodes, the cap being bonded to the base substrate to provide a hermetic seal between the interior volume of the cap and a volume exterior to the cap, and the optical window positioned and oriented to allow light emitted from the plurality of laser diodes to exit the interior volume, wherein the plurality of collimation lenses are further configured to receive the laser light through the optical window, and wherein the beam combiner is disposed external to the cap; and
at least one scan mirror positioned to receive the aggregated laser light beam, the at least one scan mirror controllably orientable to redirect the aggregated laser light beam over a range of angles onto a transparent combiner carried by an eyeglass lens coupled to the support structure.

2. The WHUD of claim 1 , further comprising a processor communicatively coupled to the laser projector to modulate generation of light signals.

3. The WHUD of claim 1 , wherein the transparent combiner is positioned within a field of view of the user, in operation the transparent combiner directs laser light from an output of the laser projector into the field of view of the user.

4. The WHUD of claim 1 , wherein the plurality of laser diodes includes a red laser diode to provide a red laser light, a green laser diode to provide a green laser light, a blue laser diode to provide a blue laser light, and an infrared laser diode to provide infrared laser light.

5. The WHUD of claim 1 , wherein the base substrate is formed from at least one of low temperature co-fired ceramic (LTCC) or alumina.

6. The WHUD of claim 1 , wherein the optical director element is disposed within the interior volume, the optical director element bonded to the base substrate proximate the plurality of laser diodes, and positioned and oriented to reflect the laser light from the plurality of laser diodes toward the plurality of collimation lenses.

7. The WHUD of claim 6 , wherein the optical director element comprises a mirror or a prism.

8. The WHUD of claim 1 , wherein the at least one laser diode driver circuit is bonded to a first surface of the base substrate, and the plurality of chip submounts and the cap are bonded to a second surface of the base substrate, the second surface of the base substrate opposite the first surface of the base substrate.

9. The WHUD of claim 1 , wherein the plurality of collimation lenses is bonded to the optical window, each of the plurality of collimation lenses positioned and oriented to receive light from a corresponding one of the plurality of laser diodes reflected by the single face of the optical director element through the optical window.

10. The WHUD of claim 1 , wherein each of the laser diodes comprises one of an edge emitter laser or a vertical-cavity surface-emitting laser (VCSEL).

11. The WHUD of claim 1 , wherein the at least one wall of the cap comprises at least one continuous sidewall having a lower first end and an upper second end, the lower first end bonded to the base substrate, and the optical window is hermetically sealed to the cap proximate the upper second end.

12. The WHUD of claim 1 , wherein the cap further comprises at least one additional wall disposed in contact with a portion of the optical window through which the light emitted from the plurality of laser diodes exits the interior volume.

13. The WHUD of claim 1 , wherein each of the plurality of laser diodes is bonded to the corresponding one of the plurality of chip submounts such that each of the plurality of laser diodes emit light in a substantially similar direction, wherein each of the plurality of chip submounts are bonded to a same surface of the base substrate.

14. The WHUD of claim 1 , further comprising:
a flange bonded to the base substrate and disposed around a perimeter of the at least one wall.

Assignees

• Google Llc

Inventors

• Pierer Jörg
• James Rony Jose
• Mohrdiek Stefan
• Dykaar Douglas Raymond

Classifications

• H04N9/3129 Primary

  scanning a light beam on the display screen (scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161) · CPC title

• G02B27/141

  using dichroic mirrors · CPC title

• G06F3/013

  Eye tracking input arrangements (G06F3/015 takes precedence) · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title

• G02B26/101

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title