Multibeam backlight, multiview display, and method with diffraction grating filling fraction

A multiview display comprising:

• a light guide configured to guide light along the light guide as guided light;
• an array of multibeam elements spaced apart from one another along the light guide and configured to scatter out the guided light from the light guide as directional light beams having directions corresponding to view directions of the multiview display, a multibeam element of the array of multibeam elements comprising a diffraction grating having diffractive features and filling features;
• and
• an array of light valves configured to modulate the directional light beams to provide a multiview image,
• wherein a filling fraction of the diffractive features relative to the filling features within the diffraction grating is configured to control a diffractive scattering efficiency of the multibeam element;
• wherein the diffractive features of the diffraction grating comprise an orientation orthogonal to a propagation direction of the guided light, the diffraction grating further comprising filling features having an orientation parallel to the propagation direction and being configured to intersect and interrupt the diffractive features of the diffraction grating to establish the filling fraction as a ratio of an area of the diffractive features relative to an area of the filling features within the diffraction grating;
• and
• wherein both the diffractive features and the filling features comprise grooves in a surface of the light guide, an intersection between a groove of the diffractive feature and a groove of the filling feature being configured to introduce a gap in the diffractive feature to interrupt the diffractive feature.

A method of multiview display operation comprising:

• guiding light along a light guide as guided light;
• scattering out a portion of the guided light as directional light beams using a multibeam element of a plurality of multibeam elements arranged along the light guide, the multibeam element comprising a diffraction grating having diffractive features and filling features that interrupt the diffractive features;
• and
• modulating the directional light beams using an array of light valves to provide a multiview image, the directional light beams having directions corresponding to view directions of the multiview image,
• wherein a filling fraction of the diffractive features relative to the filling features within the diffraction grating controls a diffractive scattering efficiency of the multibeam element as a function of distance along the light guide;
• wherein the multibeam element further comprises a reflective island having an extent corresponding to an extent of the diffraction grating and is configured to redirect a portion of diffractively scattered light in a direction of the directional light beams;
• and
• wherein the reflective island comprises a reflective material layer having openings, a ratio of an area of the reflective material layer to an area of the openings within the diffraction grating corresponding to the filling fraction of the diffractive features.