Multi-depth exit pupil expander
An example head-mounted display device includes a light projector and an eyepiece. The eyepiece includes a light guiding layer and a first focusing optical element. The first focusing optical element includes a first region having a first optical power, and a second region having a second optical power different from the first optical power. The light guiding layer is configured to: i) receive light from the light projector, ii) direct at least a first portion of the light to a user's eye through the first region to present a first virtual image to the user at a first focal distance, and iii) direct at least a second portion of the light to the user's eye through the second region to present a second virtual image to the user at a second focal distance.
1 . An eyepiece for a head-mounted display device, the eyepiece comprising:
a first progressive optical lens comprising:
a first region having a first optical power, and
a second region having a second optical power different from the first optical power, and
a second progressive optical lens comprising:
a third region having a third optical power, and
a fourth region having a fourth optical power,
wherein the third optical power is an inverse of the first optical power and the fourth optical power is an inverse of the second optical power, and
wherein the eyepiece is configured, during operation of the head-mounted display device, to:
receive light from a light projector,
direct at least a first portion of the light to a user's eye through the first region of the first progressive optical lens to present a first virtual image to the user at a first focal distance, such that the first virtual image is overlaid with the user's environment, and
direct at least a second portion of the light to the user's eye through the second region of the first progressive optical lens to present a second virtual image to the user at a second focal distance different from the first focal distance, such that the second virtual image is overlaid with the user's environment.
2 . The eyepiece of claim 1 , wherein the first progressive optical lens and the second progressive optical lens are aligned such that the first region of the first progressive optical lens at least partially overlaps with the third region of the second progressive optical lens.
3 . The eyepiece of claim 2 , wherein the first progressive optical lens and the second progressive optical lens are aligned such that the second region of the first progressive optical lens at least partially overlaps with the fourth region of the second progressive optical lens.
4 . The eyepiece of claim 1 , wherein the eyepiece is configured, during operation of the head-mounted display device, to:
receive ambient light from the user's environment,
direct at least a first portion of the ambient light to the user's eye through the third region of the second progressive optical lens and the first region of the first progressive optical lens, and
direct at least a second portion of the ambient light to the user's eye through the fourth region of the second progressive optical lens and the second region of the first progressive optical lens.
5 . The eyepiece of claim 4 , wherein the ambient light comprises light from an object positioned in the user's environment.
6 . The eyepiece of claim 1 , wherein the first progressive optical lens is a negative optical lens.
7 . The eyepiece of claim 6 , wherein the second progressive optical lens is a positive optical lens.
8 . The eyepiece of claim 1 , wherein the eyepiece is configured such that, when the head-mounted display device is worn by the user, the first region of the first progressive optical lens corresponds to a first range of gaze vectors of an eye of the user.
9 . The eyepiece of claim 8 , wherein the eyepiece is configured such that, when the head-mounted display device is worn by the user, the second region of the first progressive optical lens corresponds to a second range of gaze vectors of the eye of the user, wherein the first range of gaze vectors is different from the second range of gaze vectors.
10 . The eyepiece of claim 9 , wherein the first range of gaze vectors comprises a first gaze vector extending in a straight ahead direction from the eye of the user.
11 . The eyepiece of claim 10 , wherein the second range of gaze vectors comprises a second gaze vector extending in a vertically downward direction from the eye of the user.
12 . The eyepiece of claim 1 , wherein the first progressive optical lens further comprises:
one or more additional regions having an additional optical power different from the first optical power and the second optical power.
13 . The eyepiece of claim 12 , wherein the first progressive optical lens comprises two additional regions disposed on respective opposing sides of the first progressive optical lens, the two additional regions having an additional optical power different from the first optical power and the second optical power.
14 . The eyepiece of claim 1 , further comprising at least one of a diffractive optical element or a holographic optical element.
15 . The eyepiece of claim 1 , further comprising at least one of an analog surface relief grating (ASR), a binary surface relief structure (BSR), or a switchable diffractive optical element.
16 . A head-mounted display device comprising:
the eyepiece of claim 1 ; and
the light projector of claim 1 .
17 . An eyepiece for a head-mounted display device, the eyepiece comprising:
a first progressive optical lens comprising:
a first region having a first optical power, and
a second region having a second optical power different from the first optical power, and
a first polarizing filter and a second polarizing filter,
wherein the first polarizing filter is configured to prevent at least some light from the first region of first progressive lens from being emitted, and
wherein the second polarizing filter is configured to prevent at least some light from the second region of first progressive lens from being emitted, and
wherein the eyepiece is configured, during operation of the head-mounted display device, to:
receive light from a light projector,
direct at least a first portion of the light from the light projector to a user's eye through the first region of the first progressive optical lens to present a first virtual image to the user at a first focal distance, such that the first virtual image is overlaid with the user's environment, and
direct at least a second portion of the light to the user's eye through the second region of the first progressive optical lens to present a second virtual image to the user at a second focal distance different from the first focal distance, such that the second virtual image is overlaid with the user's environment.
18 . The eyepiece of claim 17 , wherein the first region and the second region of the first progressive optical lens are separated by a boundary, and the first optical power transitions discretely to the second optical power across the boundary.
19 . The eyepiece of claim 17 , wherein the first progressive optical lens comprises a fifth region arranged between the first region and the second region and an optical power of the fifth region continuously transitions from the first optical power to the second optical power in a direction from the first region to the second region of the first progressive optical lens.