Systems, devices, and methods for eyebox expansion in wearable heads-up displays

Patent metadata

Field	Value
Publication number	US-9989764-B2
Application number	US-201615046254-A
Country	US
Kind code	B2
Filing date	Feb 17, 2016
Priority date	Feb 17, 2015
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

Systems, devices, and methods for eyebox expansion by exit pupil replication in wearable heads-up displays (“WHUDs”) are described. A WHUD includes a scanning laser projector (“SLP”), a holographic combiner, and an optical splitter positioned in the optical path therebetween. The optical splitter receives light signals generated by the SLP and separates the light signals into N sub-ranges based on the point of incidence of each light signal at the optical splitter. The optical splitter redirects the light signals corresponding to respective ones of the N sub-ranges towards the holographic combiner effectively from respective ones of N spatially-separated virtual positions for the SLP. The holographic combiner converges the light signals to respective ones of N spatially-separated exit pupils at the eye of the user. In this way, multiple instances of the exit pupil are distributed over the area of the eye and the eyebox of the WHUD is expanded.

First claim

The invention claimed is:

1. A wearable heads-up display comprising:
a support structure that in use is worn on a head of a user;
a scanning laser projector carried by the support structure, wherein the scanning laser projector has a total scan range Ω in a first dimension, where 0°<Ω<180°;
a holographic combiner carried by the support structure, wherein the holographic combiner is positioned within a field of view of an eye of the user when the support structure is worn on the head of the user; and
an optical splitter carried by the support structure and positioned in an optical path between the scanning laser projector and the holographic combiner, the optical splitter comprising at least one optical element arranged to receive light signals generated by the scanning laser projector and redirect each light signal towards the holographic combiner effectively from one of N spatially-separated virtual positions for the scanning laser projector, where N is an integer greater than 1, the particular virtual position for the scanning laser projector from which a light signal is redirected by the optical splitter determined by a point of incidence at which the light signal is received by the optical splitter, wherein at least one optical element of the optical splitter is arranged to separate the total scan range Ω of the scanning laser projector in the first dimension into X sub-ranges ω i in the first dimension, where 1<X≤N and

∑

i
=
1

X

⁢

ω
i

=
Ω

,

and wherein each one of the X sub-ranges ω i corresponds to a different one of the N spatially-separated virtual positions for the scanning laser projector, and wherein the holographic combiner comprises at least one hologram positioned and oriented to redirect the light signals towards the eye of the user.

2. The wearable heads-up display of claim 1 wherein the scanning laser projector has a total two-dimensional scan range θ and at least one optical element of the optical splitter is arranged to separate the total two-dimensional scan range θ of the scanning laser projector into N two-dimensional sub-ranges φ i , where

∑

i
=
1

N

⁢

φ
i

=
θ

,

and wherein each one of the N sub-ranges φ i corresponds to a respective one of the N spatially-separated virtual positions for the scanning laser projector.

3. The wearable heads-up display of claim 2 wherein at least one optical element of the optical splitter is arranged to:
receive light signals corresponding to a sweep of the total two-dimensional scan range θ by the scanning laser projector;
separate the light signals corresponding to the sweep of the total two-dimensional scan range θ into the N two-dimensional sub-ranges (p, based on point of incidence at the optical splitter; and
redirect the light signals corresponding to the sweep of the total two-dimensional scan range θ towards the holographic combiner effectively from each of the N spatially-separated virtual positions for the scanning laser projector, the particular virtual position for the scanning laser projector from which each light signal in the sweep of the total two-dimensional scan range θ is redirected by the optical splitter determined by the particular two-dimensional sub-range φ i to which the light signal corresponds.

4. The wearable heads-up display of claim 1 wherein at least one optical element of the optical splitter is arranged to:
receive light signals corresponding to a sweep of the total scan range Ω in the first dimension by the scanning laser projector;
separate the light signals corresponding to the sweep of the total scan range Ω in the first dimension into the X sub-ranges coin the first dimension based on point of incidence at the optical splitter; and
redirect the light signals corresponding to the sweep of the total scan range Ω in the first dimension towards the holographic combiner effectively from at least X of the N spatially-separated virtual positions for the scanning laser projector, the particular virtual position for the scanning laser projector from which each light signal in the sweep of the total scan range Ω in the first dimension is redirected by the optical splitter determined by the particular sub-range ω i in the first dimension to which the light signal corresponds.

5. The wearable heads-up display of claim 1 wherein the scanning laser projector has a total scan range ψ in a second dimension, where 0°<ψ<180°, and at least one optical element of the optical splitter is arranged to separate the total scan range ψ of the scanning laser projector in the second dimension into Y sub-ranges β i in the second dimension, where 1<Y≤N and

∑

i
=
1

Y

⁢

β
i

=
Ψ

,

and wherein each one of the Y sub-ranges β i corresponds to a different one of the N spatially-separated virtual positions for the scanning laser projector.

6. The wearable heads-up display of claim 5 wherein at least one optical element of the optical splitter is arranged to:
receive light signals corresponding to a sweep of the total scan range ψ in the second dimension by the scanning laser projector;
separate the light signals corresponding to the sweep of the total scan range ψ in the second dimension into the Y sub-ranges β i in the second dimension based on point of incidence at the optical splitter; and
redirect the light signals corresponding to the sweep of the total scan range ψ in the second dimension towards the holographic combiner effectively from at least Y of the N spatially-separated virtual positions for the scanning laser projector, the particular virtual position for the scanning laser projector from which a light signal in the sweep of the total scan range ψ in the second dimension is redirected by the optical splitter determined by the particular sub-range β i in the second dimension to which the light signal corresponds.

7. The wearable heads-up display of claim 1 wherein the support structure has a general shape and appearance of an eyeglasses frame.

8. The wearable heads-up display of claim 7 , further comprising a prescription eyeglass lens, wherein the holographic combiner is carried by the prescription eyeglass lens.

9. The wearable heads-up display of claim 1 wherein the at least one hologram of the holographic combiner converges

Assignees

• Thalmic Labs Inc

Inventors

• Alexander Stefan
• Bailey Matthew
• Morrison Vance R
• Holland Lloyd Frederick
• Moore Joshua

Classifications

• G06F3/013

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

• G02B2027/0174

  holographic · CPC title

• G03H2001/266

  Wavelength multiplexing · CPC title

• G06F3/011

  Arrangements for interaction with the human body, e.g. for user immersion in virtual reality (blind teaching G09B21/00) · CPC title

• G02B2027/0112

  comprising device for genereting colour display · CPC title