Method for enhancing the image of autostereoscopic 3D displays based on angular filtering
View Patent ↗Embodiments include 3D display devices and methods of operation. In an example device, a light-emitting layer is provided with an addressable array of light-emitting elements. An optical layer overlays the light-emitting layer. The optical layer includes an array of lenses operative to substantially collimate light from the light-emitting layer. To suppress stay light, an angular filter layer is provided along an optical path from the light-emitting layer to an exterior of the display. The angular filter is operative to substantially block light having an incident angle greater than a threshold angle and to substantially transmit light having an incident angle less than a threshold angle. The angular filter may be a thin-film interference bandpass filter. Different regions of the angular filter may be tuned for different wavelengths of light.
1. A multiview display device comprising:
a light-emitting layer comprising an addressable array of light-emitting elements;
an optical layer overlaying the light-emitting layer, the optical layer comprising an array of lenses, wherein each respective lens overlays a group of light-emitting elements of the array of light-emitting elements and wherein light emitted from a light-emitting element of the group of light-emitting elements is collimated by the respective lens into a primary direction and collimated by another lens into a secondary direction; and
an interference filter layer along an optical path from the light-emitting layer to an exterior of the display device, the interference filter layer being operative to substantially block the light collimated into the secondary direction and to substantially transmit the light collimated into the primary direction, wherein light is transmitted if emitted from the light-emitting layer with emission angle smaller then than a first angle and is blocked if hit the optical layer with an incident angle larger than a second angle.
2. The display of claim 1 , wherein the optical layer is a substantially two-dimensional array of converging lenses.
3. The display of claim 1 , wherein the optical layer is a lenticular array.
4. The display of claim 1 , wherein the interference filter layer comprises:
a first coating on the flat lens surface of the optical layer, the first coating being operative to transmit light from the light-emitting layer having an emission angle smaller than the first angle; and
a second coating on the curved lens surface of the optical layer, the second coating being operative to block light transmitted by the first coating having an incident angle greater than the second angle.
5. The display of claim 1 , wherein the interference filter layer comprises an interference filter having a plurality of dielectric layers.
6. The display of claim 1 , wherein the interference filter layer comprises a bandpass interference filter layer.
7. The display of claim 6 , wherein the bandpass interference filter layer comprises different interference layer regions with different passbands.
8. The display of claim 6 , wherein the bandpass interference filter layer comprises:
a set of red-tuned interference layer regions with a passband substantially tuned for red light,
a set of green-tuned interference layer regions with a passband substantially tuned for green light, and
a set of blue-tuned interference layer regions with a passband substantially tuned for blue light.
9. The display of claim 8 ,
wherein each light-emitting element underlies a corresponding interference layer region,
and
wherein:
the light-emitting elements underlying the red-tuned interference layer regions are configured to emit substantially red light,
the light-emitting elements underlying the green-tuned interference layer regions are configured to emit substantially green light, and
the light-emitting elements underlying the blue-tuned interference layer regions are configured to emit substantially blue light.
10. The display of claim 1 ,
wherein the optical layer is a substantially two-dimensional array of converging lenses,
wherein the interference filter layer comprises a bandpass interference filter layer,
wherein the bandpass interference filter layer comprises different interference layer regions with different passbands, and
wherein each interference layer region corresponds to a respective one of the converging lenses.
11. The method of claim 1 , wherein the first angle is defined relative to a line perpendicular to the light-emitting layer, and wherein the second angle is defined relative to a line perpendicular to the optical layer at a location the light hits the optical layer.
12. A method of operating a multiview display device, the method comprising:
selectively operating a light-emitting layer comprising an addressable array of light-emitting elements to emit light;
at an optical layer overlaying the light-emitting layer, using an array of lenses to substantially collimate light emitted from the light-emitting layer, wherein each respective lens overlays a group of light-emitting elements of the array of light-emitting elements and wherein light emitted from a light-emitting element of the group of light-emitting elements is collimated by the respective lens into a primary direction and collimated by another lens into a secondary direction; and
transmitting the light through an interference filter layer along an optical path from the light-emitting layer to an exterior of the display device, the interference filter layer being operative to substantially block the light collimated into the secondary direction and to substantially transmit the light collimated into the primary direction, wherein light is transmitted if emitted from the light-emitting layer with emission angle smaller than a first angle and is blocked if hit the optical layer with an incident angle larger than a second angle.
13. The method of claim 12 , wherein the interference filter layer comprises:
a first coating on the flat lens surface of the optical layer, transmitting light from the light-emitting layer having an emission angle smaller than the first angle; and
a second coating on the curved lens surface of the optical layer, blocking light transmitted by the first coating having an incident angle greater than the second angle.
14. The method of claim 12 ,
wherein the optical layer is a substantially two-dimensional array of converging lenses,
wherein the interference filter layer comprises a bandpass interference filter layer,
wherein the bandpass interference filter layer comprises different interference layer regions with different passbands, and
wherein each interference layer region corresponds to a respective one of the converging lenses.
15. The method of claim 12 , wherein the interference filter layer comprises a bandpass interference filter layer.
16. The method of claim 15 , wherein the bandpass interference filter layer comprises:
a set of red-tuned interference layer regions with a passband substantially tuned for red light,
a set of green-tuned interference layer regions with a passband substantially tuned for green light, and
a set of blue-tuned interference layer regions with a passband substantially tuned for blue light.
17. The method of claim 12 , wherein the first angle is defined relative to a line perpendicular to the light-emitting layer, and wherein the second angle is defined relative to a line perpendicular to the optical layer at a location the light hits the optical layer.