Mode-selectable backlight, method, and display employing directional scattering features

A mode-selectable display comprising:

• a light guide configured to guide light;
• a plurality of light sources configured to provide guided light having different propagation directions within the light guide during different operational modes;
• a plurality of directional scattering features configured to scatter the guided light out of the light guide as emitted light, each directional scattering feature of the directional scattering feature plurality being configured to selectively scatter out guided light having a different one of the propagation directions;
• and
• an array of light valves configured to modulate the emitted light as a displayed image,
• wherein the emitted light during a selected one of the operational modes comprises a plurality of directional light beams having different principal angular directions from one another.

A method of operating a mode-selectable backlight, the method comprising:

• guiding light in a light guide as guided light;
• scattering guided light out from within the light guide as first emitted light during a first operational mode using a first directional scattering feature, the guided light having a first propagation direction during the first operational mode;
• and
• scattering guided light out from within the light guide as second emitted light during a second operational mode using a second directional scattering feature, the guided light having a second propagation direction during the second operational mode,
• wherein the second emitted light comprises a plurality of directional light beams having different principal angular directions from one another, and wherein the first and second propagation directions are different.