Variable resolution eye mounted displays
A display device (e.g., in a contact lens) is mounted on the eye. The eye mounted display contains multiple sub-displays, each of which projects light to different retinal positions within a portion of the retina corresponding to the sub-display. Additionally, a “locally uniform resolution” mapping may be used to model the variable resolution of the eye. Accordingly, various aspects of the display device may be based on the locally uniform resolution mapping. For example, the light emitted from the sub-displays may be based on the locally uniform resolution mapping.
1. An eye mounted display device comprising a contact lens containing a plurality of femto projectors, each femto projector projecting a plurality of pixels onto a user's retina when the contact lens is mounted on the user's eye, the pixels from the femto projectors creating in the aggregate an image of an object space, wherein a subset of the pixels are displayed on the retina with a size that approximately follows a locally uniform resolution mapping and the locally uniform resolution mapping is a mapping from a ScreenSurface of square pixel elements used for rendering the pixels to a ViewSphere that is a unit sphere.
2. The eye mounted display device of claim 1 , wherein the ScreenSurface is a function of coordinates (u,v), the ViewSphere is a function of coordinates (φ,θ), and the locally uniform resolution mapping is defined by
u
=
ϕ
·
SW
2
π
v
=
(
SW
2
π
·
log
e
[
tan
[
θ
2
]
]
)
-
SW
2
π
·
log
e
[
tan
[
θ
min
2
]
]
where SW is a range of the coordinate u, and θ min defines a lower limit for a range of the coordinate θ.
3. The eye mounted display device of claim 1 , wherein the subset of pixels are displayed on the retina with a magnification that approximately follows the locally uniform resolution mapping.
4. The eye mounted display device of claim 3 , wherein different femto projectors project the subset of pixels to different ranges of eccentricities, and the amount of magnification varies between femto projectors projecting to different ranges of eccentricities approximately according to the locally uniform resolution mapping.
5. The eye mounted display device of claim 1 , wherein, for the subset of pixels, the number of pixels displayed at any given eccentricity is approximately constant over a range of eccentricities.
6. The eye mounted display device of claim 1 , wherein the subset of pixels are displayed on the retina with an aspect ratio that is approximately constant over a range of eccentricities.
7. The eye mounted display device of claim 1 , wherein, pixels displayed at eccentricities below a predefined threshold are outside the subset and are displayed on the retina at an approximately fixed size on the retina.
8. The eye mounted display device of claim 7 , wherein the predefined threshold is in a range of 6 to 8 degrees of eccentricity.
9. The eye mounted display device of claim 7 , wherein the approximately fixed size is smaller than a size of pixels displayed on the retina at eccentricities above the predefined threshold.
10. The eye mounted display device of claim 1 , wherein the locally uniform resolution mapping locally preserves shape.
11. A method for displaying images of an object space, comprising:
rendering a plurality of pixels;
transmitting the plurality of rendered pixels to a plurality of femto projectors contained in a contact lens; and
the femto projectors projecting the plurality of pixels onto a user's retina when the contact lens is mounted on the user's eye, the plurality of pixels from the femto projectors creating in the aggregate an image of an object space, wherein a subset of the pixels are displayed on the retina with a size that approximately follows a locally uniform resolution mapping;
wherein rendering the plurality of pixels comprises rendering the subset of pixels on a ScreenSurface of square pixel elements, and the locally uniform resolution mapping is a mapping from the ScreenSurface to a ViewSphere that is a unit sphere.
12. The method of claim 11 , wherein the ScreenSurface is a function of coordinates (u,v), the ViewSphere is a function of coordinates (φ,θ), and the locally uniform resolution mapping is defined by
u
=
ϕ
·
SW
2
π
v
=
(
SW
2
π
·
log
e
[
tan
[
θ
2
]
]
)
-
SW
2
π
·
log
e
[
tan
[
θ
min
2
]
]
where SW is a range of the coordinate u, and θ min defines a lower limit for a range of the coordinate θ.
13. The method of claim 11 , wherein the subset of pixels are displayed on the retina with a magnification that approximately follows the locally uniform resolution mapping.
14. The method of claim 13 , wherein different femto projectors project the subset of pixels to different ranges of eccentricities, and the amount of magnification varies between femto projectors projecting to different ranges of eccentricities approximately according to the locally uniform resolution mapping.
15. The method of claim 11 , wherein, for the subset of pixels, the number of pixels displayed at any given eccentricity is approximately constant over a range of eccentricities.
16. The method of claim 11 , wherein the subset of pixels are displayed on the retina with an aspect ratio that is approximately constant over a range of eccentricities.
17. The method of claim 11 , wherein, pixels displayed at eccentricities below a predefined threshold are outside the subset and are displayed on the retina at an approximately fixed size on the retina.
18. The method of claim 17 , wherein the predefined threshold is in a range of 6 to 8 degrees of eccentricity.
19. The method of claim 17 , wherein the approximately fixed size is smaller than a size of pixels displayed on the retina at eccentricities above the predefined threshold.
20. The method of claim 19 , wherein the locally uniform resolution mapping locally preserves shape.