Patent ID: 11947315
Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Field: Optics (Instruments)
Classification: CPC G  B | IPC B  G

Claim 0:
1. A holographic projection system comprising:
a light source configured to generate a light beam;
a spatial light modulator configured to receive the light beam and generate a modulated beam projected at an eyebox, wherein the modulated beam comprises a plurality of versions of a same test image, wherein the test image comprises a plurality of bright objects and a plurality of transparent regions, and wherein the plurality of transparent regions are selected dark areas of interest for measuring luminance; and
a control module configured to run a test to characterize contrast in each of a plurality of virtual image planes of a head-up display including
controlling the spatial light modulator to generate the modulated beam,
measuring luminance levels of each of the plurality of versions of the same test image displayed in the plurality of virtual image planes,
calculating a plurality of contrast ratios based on the luminance levels of each of the plurality of versions of the same test image,
determining whether the plurality of contrast ratios are within predetermined ranges of predetermined contrast ratios, and
adjusting operation of the spatial light modulator in response to at least one of the plurality of contrast ratios not being within a corresponding one of the predetermined ranges.