Directional pixel for use in a display screen
View Patent ↗A directional pixel for use in a display screen is disclosed. The directional pixel receives a planar lightbeam and includes a light propagating layer and a grating to scatter a portion of the planar lightbeam into a directional lightbeam having a direction and angular spread controlled by the grating.
1. A directional pixel for use in a display screen, the directional pixel to receive a planar lightbeam and comprising:
a light propagating layer to propagate the planar lightbeam; and
a grating in the light propagating layer to scatter a portion of the planar lightbeam out of the light propagating layer as a directional lightbeam having a direction and an angular spread controlled by the grating,
wherein the grating in the light propagating layer is one or both of in a surface of the light propagating layer and in a material on the propagating layer surface.
2. The directional pixel of claim 1 , wherein the light propagating layer comprises a transparent Silicon-Nitride (“SiN”) layer.
3. The directional pixel of claim 1 , wherein the grating has a duty cycle around 50%.
4. The directional pixel of claim 1 , wherein the grating comprises a plurality of substantially parallel and slanted grooves, the grating having a grating period, a grating orientation, a grating length and a grating width.
5. The directional pixel of claim 4 , wherein the grating period and the grating orientation are configured to control the direction of the directional lightbeam.
6. The directional pixel of claim 4 , wherein the grating length and the grating width are configured to control the angular spread of the directional lightbeam.
7. The directional pixel of claim 1 , wherein the directional pixel is substantially planar, a front surface and a back surface of the light propagating layer being substantially parallel to one another.
8. The directional pixel of claim 1 , wherein the display screen is a multi-view display screen, the directional lightbeam having a direction corresponding to a view direction of the multi-view display screen.
9. The directional pixel of claim 1 , wherein the display screen is a privacy display screen.
10. The directional pixel of claim 4 , wherein the grating width is substantially smaller than the grating length and the display screen is a horizontal parallax only display screen.
11. A grating for use in a directional pixel in a display screen, the grating being configured to scatter an incident planar lightbeam into a directional lightbeam, the grating comprising a plurality of substantially parallel and slanted grooves having a period, an orientation, a length, and a width, the period and the orientation being configured to control a direction of the directional lightbeam, the length and the width being configured to control an angular spread of the directional lightbeam, wherein the grating is in a light propagating layer configured to guide the incident planar lightbeam.
12. The grating of claim 11 , wherein the grating is in a surface of the light propagating layer.
13. The grating of claim 11 , wherein the grating is in a material on a surface of the light propagating layer.
14. The grating of claim 11 , wherein the direction of the directional lightbeam is a function of the grating period, the grating orientation, a wavelength of the directional lightbeam, and an effective refractive index of the grating.
15. The grating of claim 11 , wherein the angular spread of the directional lightbeam is a function of the grating length, the grating width, and a wavelength of the directional lightbeam.
16. The grating of claim 11 , wherein the display screen is a multi-view display screen, the directional lightbeam having a direction corresponding to a view direction of a direction pixel of the multi-view display screen.
17. The grating of claim 11 , wherein the display screen is a privacy display screen.
18. The grating of claim 11 , wherein the grating width is substantially smaller than the grating length and the display screen is a horizontal parallax only display screen.
19. A directional pixel for use in a display screen, comprising:
a light propagating layer arranged on a substrate layer to carry a planar lightbeam; and
a grating arranged in the light propagating layer to scatter the planar lightbeam into a directional lightbeam having a direction and an angular spread controlled by the grating.
20. The directional pixel of claim 19 , wherein the grating is in a surface of the light propagating layer.
21. The directional pixel of claim 19 , wherein the grating is in a material at a surface of the light propagating layer.
22. The directional pixel of claim 19 , wherein the display screen is a multi-view display screen.
23. The directional pixel of claim 19 , wherein the display screen is a privacy display screen.