Image light guide with zoned diffractive optic

An image light guide for conveying a virtual image, comprising:

• a waveguide;
• an in-coupling diffractive optic operable to direct image-bearing light beams into said waveguide;
• and
• an out-coupling diffractive optic operable to direct said image-bearing light beams from said waveguide toward an eyebox;
• wherein said out-coupling diffractive optic comprises two or more zones each comprising a set of diffractive features;
• wherein each said set of diffractive features within each two or more zones comprises a plurality of unit cells arranged in a two-dimensional periodic lattice;
• wherein said two-dimensional periodic lattice is the same for each two or more zones within said out-coupling diffractive optic;
• and
• wherein said unit cells between at least two adjacent zones define diffractive features comprising a different shape.

An image light guide for conveying a virtual image, comprising:

• a waveguide;
• an in-coupling diffractive optic configured to direct image-bearing light beams into said waveguide;
• and
• an out-coupling diffractive optic configured to expand an eyebox in two dimensions and direct at least a portion of said image-bearing light beams from said waveguide toward said eyebox;
• wherein said out-coupling diffractive optic comprises an array of zones arranged along a first dimension and a second dimension, wherein each zone comprises a set of diffractive features;
• wherein successive zones along said first dimension of said out-coupling diffractive optic have respective sets of diffractive features with a different shape, and
• wherein said successive zones along said first dimension output a variable magnitude of a first diffracted order of said image-bearing light.