US 12,282,162 B2
Waveguide-based projection display device with a dynamic scattered light absorber for a vehicle
Michael Arthur Janzer, Unterschleissheim (DE)
Assigned to Bayerische Motoren Werke Aktiengesellschaft, Munich (DE)
Appl. No. 18/038,483
Filed by Bayerische Motoren Werke Aktiengesellschaft, Munich (DE)
PCT Filed Oct. 8, 2021, PCT No. PCT/EP2021/077915
§ 371(c)(1), (2) Date May 24, 2023,
PCT Pub. No. WO2022/156923, PCT Pub. Date Jul. 28, 2022.
Claims priority of application No. 10 2021 101 432.8 (DE), filed on Jan. 22, 2021.
Prior Publication US 2024/0012240 A1, Jan. 11, 2024
Int. Cl. G02B 27/01 (2006.01); F21V 8/00 (2006.01); G02B 5/00 (2006.01); G02B 27/00 (2006.01)
CPC G02B 27/0101 (2013.01) [G02B 5/003 (2013.01); G02B 6/005 (2013.01); G02B 27/0093 (2013.01); G02B 2027/0138 (2013.01); G02B 2027/0196 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A waveguide-based projection display device for use in a vehicle, the projection display device comprising:
an imaging unit;
a flat waveguide having a light output coupling surface formed in a flat side for a beam of light rays generated by the imaging unit, which are couplable into the waveguide laterally;
an at least partially transparent reflection pane, which is arranged in a field of view of a user and is configured to reflect a beam of light rays coupled out from the waveguide toward an eyebox intended for eyes of the user, such that a virtual display image is formed in the field of view of the user behind the reflection pane;
an eye tracking instrument, which is configured to ascertain an eyebox window currently occupied by the eyes of the user, wherein the eyebox window has a predetermined size inside the eyebox; and
a dynamic scattered light absorber, which is configured to shade the light output coupling surface in a surface segment that is dynamically adjustable as a function of the eyebox window and extends respectively from at least one edge of edges of the light output coupling surface, so that the beam of light rays coupled out from the waveguide is restricted at least partially in its cross section to the eyebox window and the eyebox window is fully illuminated.