Waveguide assembly
In various embodiments, a waveguide assembly includes first and second waveguide slabs. The first waveguide slab is to receive image-bearing light and enlarge a pupil size of the light parallel to a first axis. The first waveguide slab includes a first input-coupling device to couple image-bearing light into the first waveguide slab under total internal reflection (TIR), and a first out-coupling region to decouple image-bearing light out of the first waveguide slab by reflection. The second waveguide slab is to couple at least a portion of the out-coupled image-bearing light from the first waveguide slab into the second waveguide slab and enlarge the pupil size parallel to a second axis, which is substantially orthogonal to the first axis. The second waveguide slab includes a diffractive in-coupling region and a transmissive diffractive out-coupling region, through which a user can view real world imagery and the out-coupled image-bearing light simultaneously.
1 . A waveguide assembly comprising:
a first waveguide slab, arranged to receive image-bearing light and enlarge a pupil size of the image-bearing light parallel to a first axis, the first waveguide slab comprising a first input coupling device arranged to couple image-bearing light into the first waveguide slab under total internal reflection (TIR), and a first out-coupling region arranged to decouple image-bearing light out of the first waveguide slab by means of reflection;
a second waveguide slab, arranged to couple at least a portion of out-coupled image-bearing light from the first waveguide slab into the second waveguide slab and enlarge the pupil size parallel to a second axis, the second axis being substantially orthogonal to the first axis, the second waveguide slab comprising a diffractive in-coupling region and a transmissive diffractive out-coupling region, arranged such that a user can view real world imagery and the out-coupled image-bearing light simultaneously; and
a third waveguide slab arranged to couple, under TIR into the third waveguide slab, image-bearing light from the first waveguide slab not coupled into the second waveguide slab, the third waveguide slab comprising a transmissive diffractive out-coupling region, through which the user can view real world imagery and the out-coupled image-bearing light simultaneously, the second waveguide slab being between the first waveguide slab and the third waveguide slab, light coupled into the third waveguide slab being input into the third waveguide slab in a direct optical path from the first waveguide slab that does not pass through the second waveguide slab, such that the light does not interact with the second waveguide slab before being input into the second waveguide slab.
2 . The waveguide assembly according to claim 1 , wherein the first out-coupling region is coupled to an outer surface of the first waveguide slab.
3 . The waveguide assembly of claim 1 , wherein the image-bearing light is to be decoupled substantially uniformly across the out-coupling region.
4 . The waveguide assembly of claim 1 , wherein the first input coupling device comprises a prismatic device.
5 . The waveguide assembly of claim 1 , wherein the first out-coupling region is selected to have at least one optical characteristic selected from optical characteristics of being substantially fully reflective and being substantially non-transmissive.
6 . The waveguide assembly according to claim 1 , wherein light coupled into the third waveguide slab is configured not to interact with the second waveguide slab before being input into the second waveguide.
7 . The waveguide assembly according to claim 1 , wherein the in-coupling region of the second waveguide slab and the in-coupling region of the third waveguide slab have different grating pitch sizes that are dissimilar to one another.
8 . The waveguide assembly according to claim 1 , wherein the third waveguide slab is substantially coplanar with the second waveguide slab in the first axis and second axis and offset in a third axis, the third axis being substantially orthogonal to the first axis and the second axis.
9 . The waveguide assembly according to claim 1 , wherein the second waveguide slab and the third waveguide slab are bonded together.
10 . The waveguide assembly according to claim 1 , wherein the second waveguide slab and the third waveguide slab are different thicknesses.
11 . The waveguide assembly according to claim 1 , wherein the second waveguide is selected to have at least one physical shape chosen from shapes including a curved shaped and a non-planar shape.
12 . The waveguide assembly according to claim 1 , wherein the first waveguide slab is arranged to receive collimated image-bearing light.
13 . The waveguide assembly according to claim 1 , further comprising a collimating device to output a collimated exit pupil to be received by the first waveguide.
14 . A binocular arrangement, comprising:
a first waveguide assembly to provide a first image to a first eye of a user, and a second waveguide assembly to provide a second image to a second eye of a user, each waveguide assembly comprising:
a first waveguide slab, arranged to receive image-bearing light and enlarge a pupil size of the image-bearing light parallel to a first axis, the first waveguide slab comprising a first input coupling device arranged to couple image-bearing light into the first waveguide slab under total internal reflection (TIR), and a first out-coupling region arranged to decouple image-bearing light out of the first waveguide slab by means of reflection;
a second waveguide slab, arranged to couple at least a portion of the out-coupled image-bearing light from the first waveguide slab into the second waveguide slab and enlarge the pupil size parallel to a second axis, the second axis being substantially orthogonal to the first axis, the second waveguide slab comprising a diffractive in-coupling region and a transmissive diffractive out-coupling region, arranged such that the user can view real world imagery and the out-coupled image-bearing light simultaneously; and
a third waveguide slab arranged to couple, under TIR into the third waveguide slab, image-bearing light from the first waveguide slab not coupled into the second waveguide slab, the third waveguide slab comprising a transmissive diffractive out-coupling region, through which the user can view real world imagery and the out-coupled image-bearing light simultaneously, the second waveguide slab being between the first waveguide slab and the third waveguide slab, light coupled into the third waveguide slab being input into the third waveguide slab in a direct optical path from the first waveguide slab that does not pass through the second waveguide slab, such that the light does not interact with the second waveguide slab before being input into the second waveguide slab.
15 . The binocular arrangement of claim 14 , wherein the binocular arrangement comprises augmented reality glasses.
16 . A head-mounted display or a head-up display, comprising:
a first waveguide slab, arranged to receive image-bearing light and enlarge a pupil size of the image-bearing light parallel to a first axis, the first waveguide slab comprising a first input coupling device arranged to couple image-bearing light into the first waveguide slab under total internal reflection (TIR), and a first out-coupling region arranged to decouple image-bearing light out of the first waveguide slab by means of reflection;
a second waveguide slab, arranged to couple at least a portion of the out-coupled image-bearing light from the first waveguide slab into the second waveguide slab and enlarge the pupil size parallel to a second axis, the second axis being substantially orthogonal to the first axis, the second waveguide slab comprising a diffractive in-coupling region and a transmissive diffractive out-coupling region, arranged such that a user can view real world imagery and the out-coupled image-bearing light simultaneously; and
a third waveguide slab arranged to couple, under TIR into the third waveguide slab, image-bearing light from the first waveguide slab not coupled into the second waveguide slab, the third waveguide slab comprising a transmissive diffractive out-coupling region, through which the user can view real world imagery and the out-coupled image-bearing light simultaneously, the second waveguide slab being between the first waveguide slab and the third waveguide slab, light coupled into the third waveguide slab being input into the third waveguide slab in a direct optical path from the first waveguide slab that does not pass through the second waveguide slab, such that the light does not interact with the second waveguide slab before being input into the second waveguide slab.