Patent ID: 11906828
Assignee: SIOPTICA GMBH
Field: Optics (Instruments)
Classification: CPC G | IPC F  G

Claim 19:
20. A display screen which can be operated in at least two operating modes, a first operating mode for a free viewing mode and a second operating mode for a limited viewing mode, comprising:
a two-dimensionally extensive backlight which contains an optical element according to claim 10 and which emits light, the back light configured to be switched on in the second operating mode,
a plate-shaped light guide which is located in front of the backlight in a viewing direction and which has out-coupling elements on a surface of the light guide and/or within a volume of the light guide, wherein the light guide is at least 40% transparent to light emanating from the backlight,
illuminants arranged laterally on at least one narrow side of the light guide, the illuminants configured to be switched on in the first operating mode and switched off in the second operating mode,
a linear polarization filter arranged in front of the backlight or in front of the light guide in the viewing direction so that light emanating from the backlight and passing through the polarization filter is limited with respect to its propagation directions,
a transmissive imaging display device which is arranged upstream of the light guide in the viewing direction and in which the linear polarization filter is arranged.