Light turning feature patterns for lightguides

An apparatus comprising:

• one or more light emitters;
• and
• a light guide comprising:
• an array of light turning means, each light turning means configured to turn light from the one or more light emitters,
• wherein the light turning means are spaced apart along a first axis such that distances separating adjacent light turning means vary non-monotonically along the first axis, and
• wherein the light turning means occupy rows extending parallel to a second axis that crosses the first axis, wherein neighboring light turning means in each of the rows are spaced apart from each other with substantially the same progression along the second axis.

A computer-implemented method comprising:

• under control of one or more configured computer systems,
• obtaining an intensity profile corresponding to an initial placement of light turning features within an area of a light guide;
• determining, based on the intensity profile, a plurality of desired pitches between pairs of light turning features along a first axis, each desired pitch corresponding to a position within the area and along the first axis;
• and
• deriving, based on the desired pitches, an updated placement of light turning features within the area, wherein one or more pitches between adjacent light turning features of the initial placement along the first axis are adjusted in the updated placement.