US 11,947,315 B2
Contrast characterization of multi-plane holographic HUD accounting for image artifacts
Thomas A. Seder, Fraser, MI (US); and Kai-Han Chang, Madison Heights, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Apr. 22, 2021, as Appl. No. 17/237,815.
Prior Publication US 2022/0342367 A1, Oct. 27, 2022
Int. Cl. G09G 5/02 (2006.01); B60K 35/00 (2006.01); G03H 1/22 (2006.01); G06F 3/01 (2006.01); G06T 7/521 (2017.01); G06T 7/90 (2017.01)
CPC G03H 1/2294 (2013.01) [B60K 35/00 (2013.01); G03H 1/2249 (2013.01); G06F 3/013 (2013.01); G06T 7/521 (2017.01); G06T 7/90 (2017.01); B60K 2370/1529 (2019.05); B60K 2370/29 (2019.05); G03H 2001/2284 (2013.01); G03H 2225/30 (2013.01)] 20 Claims
OG exemplary drawing
 
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.