Light-Transmitting Pane for Displaying an Image of a Head-Up Display for Polarized Sunglasses

• US 20140307176A1
• Filed: 04/11/2014
• Published: 10/16/2014
• Est. Priority Date: 04/12/2013
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: NEUMANN, Alexander, COSTA, Louis
• Granted Patent: US 10,551,621 B2
• Time in Patent Office: Days
• US Class Current: 349/11
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0149 characterised by mechanical features G02B27/0176 takes precedence
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02F 1/0045 Liquid crystals characterised by their physical properties

Abstract

A light-transmitting pane for displaying an image of a head-up display is provided. The light-transmitting pane includes a cholesteric liquid-crystal layer arrangement, which is arranged in the interior of the pane or is arranged on a surface of the pane. Depending on the polarization of the incident light, at least a portion of the light generated by an image generating device of a head-up display arrangement can be reflected on the cholesteric liquid-crystal layer arrangement such that the reflected light has a p-polarized fraction, which can be perceived through polarized sunglasses.

Claims

1-15. -15. (canceled)

16. A light-transmitting pane for a head-up display arrangement for displaying an image that is visible through polarized sunglasses, the light-transmitting pane comprising:

a cholesteric liquid-crystal layer arrangement, which is arranged in an interior of the pane or is arranged on a surface of the pane.

17. The light-transmitting pane according to claim 16, wherein:

the cholesteric liquid-crystal layer arrangement comprises at least one helical molecule arrangement with a pitch in a layer plane, and

the at least one helical molecule arrangement is spirally wound and has a chirality within a period of the pitch.

18. The light-transmitting pane according to claim 17,

wherein the at least one helical molecule arrangement has a right-handed winding of its molecules within the period of the pitch.

19. The light-transmitting pane according to claim 16, wherein:

the cholesteric liquid-crystal layer arrangement comprises a plurality of helical molecule arrangements in different layer planes that are arranged above one another,

the helical molecule arrangements in the different layer planes have at least one of a different pitch or a different overall length, and

the helical molecule arrangements in the different layer planes have a same chirality.

20. The light-transmitting pane according to claim 16, wherein:

the cholesteric liquid-crystal layer arrangement comprises first helical molecule arrangements and second helical molecule arrangements,

the first helical molecule arrangements are arranged in different first layer planes that are arranged above one another, and the first helical molecule arrangements in the different first layer planes have at least one of a different pitch or a different overall length,

the second helical molecule arrangements are arranged in different second layer planes that are arranged above one another, and the second helical molecule arrangements in the different second layer planes have at least one of a different pitch or a different overall length,

the second layer planes are arranged above or below the first layer planes, and

the first helical molecule arrangements have a different chirality than the second helical molecule arrangements.

21. The light-transmitting pane according to claim 16,

wherein the cholesteric liquid-crystal layer arrangement is arranged on a substrate.

22. The light-transmitting pane according to claim 21,

wherein the substrate is a polymer layer.

23. The light-transmitting pane according to claim 21,

wherein the substrate is embedded in the interior of the pane.

24. The light-transmitting pane according to claim 21,

wherein the substrate is constructed as a polymer foil and is arranged on a surface of the pane.

25. A head-up display arrangement comprising:

a light-transmitting pane comprising a cholesteric liquid-crystal layer arrangement, which is arranged in an interior of the pane or is arranged on a surface of the pane; and

an image generating device for generating a virtual image from rays of light generated at an output side of the image generating device,

wherein the pane and the image generating device are arranged such that the light generated by the image generating device impinges on the cholesteric liquid-crystal layer arrangement.

26. The head-up display arrangement according to claim 25,

wherein the cholesteric liquid-crystal layer arrangement is configured to reflect at least a portion of the light impinging on the cholesteric liquid-crystal layer arrangement.

27. A head-up display arrangement according to claim 25,

wherein the image generating device is configured to generate circularly polarized light.

28. The head-up display arrangement according to claim 25,

wherein the image generating device is configured to generate light that is polarized exclusively parallel to a plane of incidence of the pane.

29. The head-up display arrangement according to claim 26,

wherein the cholesteric liquid-crystal layer arrangement is configured to reflect the portion of the light impinging on the cholesteric liquid-crystal layer arrangement as circularly polarized light.

30. The head-up display arrangement according to claim 25,

wherein the cholesteric liquid-crystal layer arrangement is configured to transmit at least 70% of non-polarized light impinging on the cholesteric liquid-crystal layer arrangement.

31. A vehicle comprising:

a head-up display comprising;

a light-transmitting pane comprising a cholesteric liquid-crystal layer arrangement, which is arranged in an interior of the pane or is arranged on a surface of the pane; and

an image generating device for generating a virtual image from rays of light generated at an output side of the image generating device,

wherein the pane and the image generating device are arranged such that the light generated by the image generating device impinges on the cholesteric liquid-crystal layer arrangement.