Light field display
An angular image of a scene may be displayed using a light field display. The light field display may comprise a plurality of projection units. Each of the projections units may comprise an imaging system and an optical system. The imaging system may illuminate pixels of a planar image of the scene. Light corresponding to each of the pixels may be directed towards the optical system. The optical system may comprise first and second lenses for redirecting each light beam corresponding to a pixel in different directions. In some embodiments the first and second lenses form a globe lens. A diffusion system may conceal the optical systems. Additionally, or alternatively, the diffusion system may produce a uniform distribution of light at a plurality of different viewing angles.
1. A light field display for displaying an angular image, the light field display comprising:
a plurality of projection units spaced laterally apart from one another in one or more lateral directions, each projection unit having an optical axis which is orthogonal to the one or more lateral directions, each projection unit comprising:
an imaging system for providing a precursor image on an image plane;
an optical system comprising one or more lenses shaped and located to receive light from pixels of the precursor image and to emit redirected light transmitted therethrough;
a diffusion system located to receive the redirected light and operative to laterally spread light that is transmitted therethrough and to thereby emit diffuse light;
wherein the diffuse light emitted from the diffusion systems of the plurality of projection units provides an angular image perceptible to a human viewer;
wherein adjacent pixels of the precursor image are directed at different angles of the angular image; and
wherein the lateral spreading of the diffuse light emitted from the diffusion systems of the plurality of projection units obfuscates the existence of the projection units from being discernable within the angular image by the human viewer;
wherein the diffusion system comprises one or more diffusion elements, each of which is shaped by patterning and/or located relative to other components of the light field display to achieve a desired tradeoff between minimizing spatial diffusion of the diffuse light and spatial uniformity of the diffuse light.
2. The light field display according to claim 1 wherein the diffusion system comprises a first diffuser proximate, in an axial direction, to the optical system and a second diffuser spaced apart, in the axial direction, from the first diffuser.
3. The light field display according to claim 1 wherein the optical system further comprises a first lens and a second lens that are shaped and/or located to provide a globe lens.
4. The light field display according to claim 1 wherein the optical system further comprises a first lens and a second lens and an optical aperture located in a gap between the first and second lenses.
5. The light field display according to claim 1 wherein each of the projection units has a lateral cross-section dimension of about 2.5 cm.
6. The light field display according to claim 1 wherein the image plane is operable to compensate for distortions introduced by the optical system.
7. A light field display for displaying an angular image, the light field display comprising:
a plurality of projection units spaced laterally apart from one another in one or more lateral directions, each projection unit having an optical axis which is orthogonal to the one or more lateral directions, each projection unit comprising:
an imaging system for providing a precursor image on an image plane;
an optical system comprising one or more lenses shaped and located to receive light from pixels of the precursor image and to emit redirected light transmitted therethrough;
a diffusion system located to receive the redirected light and operative to laterally spread light that is transmitted therethrough and to thereby emit diffuse light;
wherein the diffuse light emitted from the diffusion systems of the plurality of projection units provides an angular image perceptible to a human viewer;
wherein adjacent pixels of the precursor image are directed at different angles of the angular image; and
wherein the lateral spreading of the diffuse light emitted from the diffusion systems of the plurality of projection units obfuscates the existence of the projection units from being discernable within the angular image by the human viewer;
wherein the angular image has a plurality of depth planes;
wherein the diffusion system comprises one or more diffusion elements, each of which is shaped by patterning and/or located relative to other components of the light field display to achieve a desired tradeoff between minimizing spatial diffusion of the diffuse light and spatial uniformity of the diffuse light.
8. The light field display according to claim 7 wherein the diffusion system comprises a first diffuser proximate, in an axial direction, to the optical system and a second diffuser spaced apart, in the axial direction, from the first diffuser.
9. The light field display according to claim 7 wherein the optical system further comprises a first lens and a second lens, wherein one or both of the first and second lenses comprise faceted surfaces.
10. The light field display according to claim 7 wherein the image plane is operable to compensate for distortions introduced by the optical system.
11. The light field display according to claim 7 wherein the image plane comprises red, green and blue precursor images, each of the precursor images generated in a different way to compensate for chromatic aberration.
12. A light field display for displaying an angular image, the light field display comprising:
a plurality of projection units spaced laterally apart from one another in one or more lateral directions, each projection unit having an optical axis which is orthogonal to the one or more lateral directions, each projection unit comprising:
an imaging system for providing a precursor image on an image plane;
an optical system comprising one or more lenses shaped and located to receive light from pixels of the precursor image and to emit redirected light transmitted therethrough;
a diffusion system located to receive the redirected light and operative to laterally spread light that is transmitted therethrough and to thereby emit diffuse light;
wherein the diffuse light emitted from the diffusion systems of the plurality of projection units provides an angular image perceptible to a human viewer;
wherein adjacent pixels of the precursor image are directed at different angles of the angular image; and
wherein the lateral spreading of the diffuse light emitted from the diffusion systems of the plurality of projection units obfuscates the existence of the projection units from being discernable within the angular image by the human viewer;
wherein the diffusion system is shaped, for a given viewing angle ø, to produce a distribution of light provided at least approximately by L(ø), where:
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and wherein lens spacing is an axial direction distance between opposing inner surfaces of lenses of the optical system and d diffuser spacing is an axial distance between the first and second diffusers.
13. The light field display according to claim 12 wherein the optical system further comprises a first and a second lens, wherein one or both of the first and second lenses comprise a Fresnel lens.
14. A light field display for displaying an angular image, the light field display comprising:
a plurality of projection units spaced laterally apart from one another in one or more lateral directions, each projection unit having an optical axis which is orthogonal to the one or more lateral directions, each projection unit comprising:
an imaging system for providing a precursor image on an image plane;
an optical system comprising one or more lenses shaped and located to receive light from pixels of the precursor image and to emit redirected light transmitted therethrough;
a diffusion system located to receive the redirected light and operative to laterally spread light that is transmitted therethrough and to thereby emit diffuse light;
wherein the diffuse light emitted from the diffusion systems of the plurality of projection units provides an angular image perceptible to a human viewer;
wherein adjacent pixels of the precursor image are directed at different angles of the angular image; and
wherein the lateral spreading of the diffuse light emitted from the diffusion systems of the plurality of projection units obfuscates the existence of the projection units from being discernable within the angular image by the human viewer;
wherein each of the plurality of projection units:
is arranged to form a lateral grid-like pattern of projection units that spans a laterally extending plane of the light field display; and
comprises a light source operable to emit light and a field lens shaped and/or located to:
receive the emitted light; and
focus the emitted light through an aperture of the optical system.
15. A light field display for displaying an angular image, the light field display comprising:
a plurality of projection units spaced laterally apart from one another in one or more lateral directions, each projection unit having an optical axis which is orthogonal to the one or more lateral directions, each projection unit comprising:
an imaging system for providing a precursor image on an image plane;
an optical system comprising one or more lenses shaped and located to receive light from pixels of the precursor image and to emit redirected light transmitted therethrough;
a diffusion system located to receive the redirected light and operative to laterally spread light that is transmitted therethrough and to thereby emit diffuse light;
wherein the diffuse light emitted from the diffusion systems of the plurality of projection units provides an angular image perceptible to a human viewer;
wherein adjacent pixels of the precursor image are directed at different angles of the angular image; and
wherein the lateral spreading of the diffuse light emitted from the diffusion systems of the plurality of projection units obfuscates the existence of the projection units from being discernable within the angular image by the human viewer;
wherein the image plane is an active element that is operable to update the precursor image at any time.
16. A light field display for displaying an angular image, the light field display comprising:
a plurality of projection units spaced laterally apart from one another in one or more lateral directions, each projection unit having an optical axis which is orthogonal to the one or more lateral directions, each projection unit comprising:
an imaging system for providing a precursor image on an image plane;
an optical system comprising one or more lenses shaped and located to receive light from pixels of the precursor image and to emit redirected light transmitted therethrough;
a diffusion system located to receive the redirected light and operative to laterally spread light that is transmitted therethrough and to thereby emit diffuse light;
wherein the diffuse light emitted from the diffusion systems of the plurality of projection units provides an angular image perceptible to a human viewer;
wherein adjacent pixels of the precursor image are directed at different angles of the angular image; and
wherein the lateral spreading of the diffuse light emitted from the diffusion systems of the plurality of projection units obfuscates the existence of the projection units from being discernable within the angular image by the human viewer;
wherein the angular image has a plurality of depth planes;
wherein the image plane is an active element that is operable to update the precursor image at any time.
17. A light field display for displaying an angular image, the light field display comprising:
a plurality of projection units spaced laterally apart from one another in one or more lateral directions, each projection unit having an optical axis which is orthogonal to the one or more lateral directions, each projection unit comprising:
an imaging system for providing a precursor image on an image plane;
an optical system comprising one or more lenses shaped and located to receive light from pixels of the precursor image and to emit redirected light transmitted therethrough;
a diffusion system located to receive the redirected light and operative to laterally spread light that is transmitted therethrough and to thereby emit diffuse light;
wherein the diffuse light emitted from the diffusion systems of the plurality of projection units provides an angular image perceptible to a human viewer;
wherein adjacent pixels of the precursor image are directed at different angles of the angular image; and
wherein the lateral spreading of the diffuse light emitted from the diffusion systems of the plurality of projection units obfuscates the existence of the projection units from being discernable within the angular image by the human viewer;
wherein the angular image has a plurality of depth planes;
one or more motion sensors operative to detect one or more changes in orientation of the light field display; and
an image processing engine configured to adjust the precursor image based on the one or more detected changes in orientation to produce an angular image that counters one or more of the detected changes in orientation.