US 12,345,897 B2
Glare mitigation module for a head-up display system
Kai-Han Chang, Madison Heights, MI (US); and Thomas A. Seder, Fraser, MI (US)
Assigned to GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed by GM Global Technology Operations LLC, Detroit, MI (US)
Filed on Mar. 22, 2022, as Appl. No. 17/700,920.
Prior Publication US 2023/0305311 A1, Sep. 28, 2023
Int. Cl. G02B 27/42 (2006.01); B60K 35/00 (2024.01); B60K 35/23 (2024.01); B60K 35/40 (2024.01); G02B 5/18 (2006.01); G02B 27/01 (2006.01)
CPC G02B 27/4233 (2013.01) [B60K 35/00 (2013.01); G02B 5/1861 (2013.01); G02B 27/0101 (2013.01); B60K 35/23 (2024.01); B60K 35/415 (2024.01); B60K 2360/333 (2024.01); G02B 2027/0118 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A glare mitigation module for use with a head-up display system and configured to transmit display light emitted from an illumination device therethrough, the glare mitigation module comprising:
an input surface through which the display light from the illumination device enters the glare mitigation module;
an output surface through which the display light from the illumination device exits the glare mitigation module in a display direction; and
a diffractive optical element comprising a plurality of layers stacked successively between the input and output surfaces, with the plurality of layers arranged to transmit the display light of the illumination device therethrough and to diffract an external light that enters the glare mitigation module through the output surface, wherein the diffractive optical element is arranged to diffract the external light in a diffracted direction away from eyes of an occupant, and wherein for each of the plurality of layers a thickness is about 10 μm, a ratio between a periodicity λ and a central wavelength λ is from 3:1 to 1:1, and a refractive index is from 1.4 to 1.8.